f2c49dd248
prime objectives are: o Implement a syscall path based on the epc inststruction (see sys/ia64/ia64/syscall.s). o Revisit the places were we need to save and restore registers and define those contexts in terms of the register sets (see sys/ia64/include/_regset.h). Secundairy objectives: o Remove the requirement to use contigmalloc for kernel stacks. o Better handling of the high FP registers for SMP systems. o Switch to the new cpu_switch() and cpu_throw() semantics. o Add a good unwinder to reconstruct contexts for the rare cases we need to (see sys/contrib/ia64/libuwx) Many files are affected by this change. Functionally it boils down to: o The EPC syscall doesn't preserve registers it does not need to preserve and places the arguments differently on the stack. This affects libc and truss. o The address of the kernel page directory (kptdir) had to be unstaticized for use by the nested TLB fault handler. The name has been changed to ia64_kptdir to avoid conflicts. The renaming affects libkvm. o The trapframe only contains the special registers and the scratch registers. For syscalls using the EPC syscall path no scratch registers are saved. This affects all places where the trapframe is accessed. Most notably the unaligned access handler, the signal delivery code and the debugger. o Context switching only partly saves the special registers and the preserved registers. This affects cpu_switch() and triggered the move to the new semantics, which additionally affects cpu_throw(). o The high FP registers are either in the PCB or on some CPU. context switching for them is done lazily. This affects trap(). o The mcontext has room for all registers, but not all of them have to be defined in all cases. This mostly affects signal delivery code now. The *context syscalls are as of yet still unimplemented. Many details went into the removal of the requirement to use contigmalloc for kernel stacks. The details are mostly CPU specific and limited to exception_save() and exception_restore(). The few places where we create, destroy or switch stacks were mostly simplified by not having to construct physical addresses and additionally saving the virtual addresses for later use. Besides more efficient context saving and restoring, which of course yields a noticable speedup, this also fixes the dreaded SMP bootup problem as a side-effect. The details of which are still not fully understood. This change includes all the necessary backward compatibility code to have it handle older userland binaries that use the break instruction for syscalls. Support for break-based syscalls has been pessimized in favor of a clean implementation. Due to the overall better performance of the kernel, this will still be notived as an improvement if it's noticed at all. Approved by: re@ (jhb)
2056 lines
49 KiB
C
2056 lines
49 KiB
C
/*
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|
* Copyright (C) 2001 Julian Elischer <julian@freebsd.org>.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice(s), this list of conditions and the following disclaimer as
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* the first lines of this file unmodified other than the possible
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* addition of one or more copyright notices.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice(s), this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/smp.h>
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#include <sys/sysctl.h>
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#include <sys/sysproto.h>
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#include <sys/filedesc.h>
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#include <sys/sched.h>
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#include <sys/signalvar.h>
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#include <sys/sx.h>
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#include <sys/tty.h>
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#include <sys/user.h>
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#include <sys/jail.h>
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#include <sys/kse.h>
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#include <sys/ktr.h>
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#include <sys/ucontext.h>
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#include <vm/vm.h>
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#include <vm/vm_object.h>
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#include <vm/pmap.h>
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#include <vm/uma.h>
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#include <vm/vm_map.h>
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#include <machine/frame.h>
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/*
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* KSEGRP related storage.
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*/
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static uma_zone_t ksegrp_zone;
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static uma_zone_t kse_zone;
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static uma_zone_t thread_zone;
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static uma_zone_t upcall_zone;
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/* DEBUG ONLY */
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SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0, "thread allocation");
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static int thread_debug = 0;
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SYSCTL_INT(_kern_threads, OID_AUTO, debug, CTLFLAG_RW,
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&thread_debug, 0, "thread debug");
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static int max_threads_per_proc = 150;
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SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW,
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&max_threads_per_proc, 0, "Limit on threads per proc");
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static int max_groups_per_proc = 50;
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SYSCTL_INT(_kern_threads, OID_AUTO, max_groups_per_proc, CTLFLAG_RW,
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&max_groups_per_proc, 0, "Limit on thread groups per proc");
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static int max_threads_hits;
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SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD,
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&max_threads_hits, 0, "");
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static int virtual_cpu;
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#define RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start))
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TAILQ_HEAD(, thread) zombie_threads = TAILQ_HEAD_INITIALIZER(zombie_threads);
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TAILQ_HEAD(, kse) zombie_kses = TAILQ_HEAD_INITIALIZER(zombie_kses);
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TAILQ_HEAD(, ksegrp) zombie_ksegrps = TAILQ_HEAD_INITIALIZER(zombie_ksegrps);
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TAILQ_HEAD(, kse_upcall) zombie_upcalls =
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TAILQ_HEAD_INITIALIZER(zombie_upcalls);
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struct mtx kse_zombie_lock;
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MTX_SYSINIT(kse_zombie_lock, &kse_zombie_lock, "kse zombie lock", MTX_SPIN);
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static void kse_purge(struct proc *p, struct thread *td);
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static void kse_purge_group(struct thread *td);
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static int thread_update_usr_ticks(struct thread *td, int user);
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static void thread_alloc_spare(struct thread *td, struct thread *spare);
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static int
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sysctl_kse_virtual_cpu(SYSCTL_HANDLER_ARGS)
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{
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int error, new_val;
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int def_val;
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#ifdef SMP
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def_val = mp_ncpus;
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#else
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def_val = 1;
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#endif
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if (virtual_cpu == 0)
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new_val = def_val;
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else
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new_val = virtual_cpu;
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error = sysctl_handle_int(oidp, &new_val, 0, req);
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if (error != 0 || req->newptr == NULL)
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return (error);
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if (new_val < 0)
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return (EINVAL);
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virtual_cpu = new_val;
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return (0);
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}
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/* DEBUG ONLY */
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SYSCTL_PROC(_kern_threads, OID_AUTO, virtual_cpu, CTLTYPE_INT|CTLFLAG_RW,
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0, sizeof(virtual_cpu), sysctl_kse_virtual_cpu, "I",
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"debug virtual cpus");
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/*
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* Prepare a thread for use.
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*/
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static void
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thread_ctor(void *mem, int size, void *arg)
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{
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struct thread *td;
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td = (struct thread *)mem;
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td->td_state = TDS_INACTIVE;
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td->td_oncpu = NOCPU;
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}
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/*
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* Reclaim a thread after use.
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*/
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static void
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thread_dtor(void *mem, int size, void *arg)
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{
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struct thread *td;
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td = (struct thread *)mem;
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#ifdef INVARIANTS
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/* Verify that this thread is in a safe state to free. */
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switch (td->td_state) {
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case TDS_INHIBITED:
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case TDS_RUNNING:
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case TDS_CAN_RUN:
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case TDS_RUNQ:
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/*
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* We must never unlink a thread that is in one of
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* these states, because it is currently active.
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*/
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panic("bad state for thread unlinking");
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/* NOTREACHED */
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case TDS_INACTIVE:
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break;
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default:
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panic("bad thread state");
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/* NOTREACHED */
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}
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#endif
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}
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/*
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* Initialize type-stable parts of a thread (when newly created).
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*/
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static void
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thread_init(void *mem, int size)
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{
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struct thread *td;
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td = (struct thread *)mem;
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mtx_lock(&Giant);
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pmap_new_thread(td, 0);
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mtx_unlock(&Giant);
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cpu_thread_setup(td);
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td->td_sched = (struct td_sched *)&td[1];
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}
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/*
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* Tear down type-stable parts of a thread (just before being discarded).
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*/
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static void
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thread_fini(void *mem, int size)
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{
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struct thread *td;
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td = (struct thread *)mem;
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pmap_dispose_thread(td);
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}
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/*
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* Initialize type-stable parts of a kse (when newly created).
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*/
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static void
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kse_init(void *mem, int size)
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{
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struct kse *ke;
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ke = (struct kse *)mem;
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ke->ke_sched = (struct ke_sched *)&ke[1];
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}
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/*
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* Initialize type-stable parts of a ksegrp (when newly created).
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*/
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static void
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ksegrp_init(void *mem, int size)
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{
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struct ksegrp *kg;
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kg = (struct ksegrp *)mem;
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kg->kg_sched = (struct kg_sched *)&kg[1];
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}
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/*
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* KSE is linked into kse group.
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*/
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void
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kse_link(struct kse *ke, struct ksegrp *kg)
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{
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struct proc *p = kg->kg_proc;
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TAILQ_INSERT_HEAD(&kg->kg_kseq, ke, ke_kglist);
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kg->kg_kses++;
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ke->ke_state = KES_UNQUEUED;
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ke->ke_proc = p;
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ke->ke_ksegrp = kg;
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ke->ke_thread = NULL;
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ke->ke_oncpu = NOCPU;
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ke->ke_flags = 0;
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}
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void
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kse_unlink(struct kse *ke)
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{
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struct ksegrp *kg;
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mtx_assert(&sched_lock, MA_OWNED);
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kg = ke->ke_ksegrp;
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TAILQ_REMOVE(&kg->kg_kseq, ke, ke_kglist);
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if (ke->ke_state == KES_IDLE) {
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TAILQ_REMOVE(&kg->kg_iq, ke, ke_kgrlist);
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kg->kg_idle_kses--;
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}
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if (--kg->kg_kses == 0)
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ksegrp_unlink(kg);
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/*
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* Aggregate stats from the KSE
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*/
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kse_stash(ke);
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}
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void
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ksegrp_link(struct ksegrp *kg, struct proc *p)
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{
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TAILQ_INIT(&kg->kg_threads);
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TAILQ_INIT(&kg->kg_runq); /* links with td_runq */
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TAILQ_INIT(&kg->kg_slpq); /* links with td_runq */
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TAILQ_INIT(&kg->kg_kseq); /* all kses in ksegrp */
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TAILQ_INIT(&kg->kg_iq); /* all idle kses in ksegrp */
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TAILQ_INIT(&kg->kg_upcalls); /* all upcall structure in ksegrp */
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kg->kg_proc = p;
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/*
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* the following counters are in the -zero- section
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* and may not need clearing
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*/
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kg->kg_numthreads = 0;
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kg->kg_runnable = 0;
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kg->kg_kses = 0;
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kg->kg_runq_kses = 0; /* XXXKSE change name */
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kg->kg_idle_kses = 0;
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kg->kg_numupcalls = 0;
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/* link it in now that it's consistent */
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p->p_numksegrps++;
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TAILQ_INSERT_HEAD(&p->p_ksegrps, kg, kg_ksegrp);
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}
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void
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ksegrp_unlink(struct ksegrp *kg)
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{
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struct proc *p;
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mtx_assert(&sched_lock, MA_OWNED);
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KASSERT((kg->kg_numthreads == 0), ("ksegrp_unlink: residual threads"));
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KASSERT((kg->kg_kses == 0), ("ksegrp_unlink: residual kses"));
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KASSERT((kg->kg_numupcalls == 0), ("ksegrp_unlink: residual upcalls"));
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p = kg->kg_proc;
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TAILQ_REMOVE(&p->p_ksegrps, kg, kg_ksegrp);
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p->p_numksegrps--;
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/*
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* Aggregate stats from the KSE
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*/
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ksegrp_stash(kg);
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}
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struct kse_upcall *
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upcall_alloc(void)
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{
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struct kse_upcall *ku;
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ku = uma_zalloc(upcall_zone, M_WAITOK);
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bzero(ku, sizeof(*ku));
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return (ku);
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}
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void
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upcall_free(struct kse_upcall *ku)
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{
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uma_zfree(upcall_zone, ku);
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}
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void
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upcall_link(struct kse_upcall *ku, struct ksegrp *kg)
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{
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mtx_assert(&sched_lock, MA_OWNED);
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TAILQ_INSERT_TAIL(&kg->kg_upcalls, ku, ku_link);
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ku->ku_ksegrp = kg;
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kg->kg_numupcalls++;
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}
|
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|
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void
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upcall_unlink(struct kse_upcall *ku)
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{
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struct ksegrp *kg = ku->ku_ksegrp;
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mtx_assert(&sched_lock, MA_OWNED);
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KASSERT(ku->ku_owner == NULL, ("%s: have owner", __func__));
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TAILQ_REMOVE(&kg->kg_upcalls, ku, ku_link);
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kg->kg_numupcalls--;
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upcall_stash(ku);
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}
|
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void
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upcall_remove(struct thread *td)
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{
|
|
|
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if (td->td_upcall) {
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td->td_upcall->ku_owner = NULL;
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upcall_unlink(td->td_upcall);
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td->td_upcall = 0;
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}
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}
|
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|
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/*
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* For a newly created process,
|
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* link up all the structures and its initial threads etc.
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|
*/
|
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void
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proc_linkup(struct proc *p, struct ksegrp *kg,
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struct kse *ke, struct thread *td)
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{
|
|
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TAILQ_INIT(&p->p_ksegrps); /* all ksegrps in proc */
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TAILQ_INIT(&p->p_threads); /* all threads in proc */
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TAILQ_INIT(&p->p_suspended); /* Threads suspended */
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p->p_numksegrps = 0;
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p->p_numthreads = 0;
|
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ksegrp_link(kg, p);
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kse_link(ke, kg);
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thread_link(td, kg);
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}
|
|
|
|
/*
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struct kse_thr_interrupt_args {
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struct kse_thr_mailbox * tmbx;
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};
|
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*/
|
|
int
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kse_thr_interrupt(struct thread *td, struct kse_thr_interrupt_args *uap)
|
|
{
|
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struct proc *p;
|
|
struct thread *td2;
|
|
|
|
p = td->td_proc;
|
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if (!(p->p_flag & P_THREADED) || (uap->tmbx == NULL))
|
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return (EINVAL);
|
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mtx_lock_spin(&sched_lock);
|
|
FOREACH_THREAD_IN_PROC(p, td2) {
|
|
if (td2->td_mailbox == uap->tmbx) {
|
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td2->td_flags |= TDF_INTERRUPT;
|
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if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR)) {
|
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if (td2->td_flags & TDF_CVWAITQ)
|
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cv_abort(td2);
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else
|
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abortsleep(td2);
|
|
}
|
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mtx_unlock_spin(&sched_lock);
|
|
return (0);
|
|
}
|
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}
|
|
mtx_unlock_spin(&sched_lock);
|
|
return (ESRCH);
|
|
}
|
|
|
|
/*
|
|
struct kse_exit_args {
|
|
register_t dummy;
|
|
};
|
|
*/
|
|
int
|
|
kse_exit(struct thread *td, struct kse_exit_args *uap)
|
|
{
|
|
struct proc *p;
|
|
struct ksegrp *kg;
|
|
struct kse *ke;
|
|
|
|
p = td->td_proc;
|
|
if (td->td_upcall == NULL || TD_CAN_UNBIND(td))
|
|
return (EINVAL);
|
|
kg = td->td_ksegrp;
|
|
/* Serialize removing upcall */
|
|
PROC_LOCK(p);
|
|
mtx_lock_spin(&sched_lock);
|
|
if ((kg->kg_numupcalls == 1) && (kg->kg_numthreads > 1)) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_UNLOCK(p);
|
|
return (EDEADLK);
|
|
}
|
|
ke = td->td_kse;
|
|
upcall_remove(td);
|
|
if (p->p_numthreads == 1) {
|
|
kse_purge(p, td);
|
|
p->p_flag &= ~P_THREADED;
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_UNLOCK(p);
|
|
} else {
|
|
if (kg->kg_numthreads == 1) { /* Shutdown a group */
|
|
kse_purge_group(td);
|
|
ke->ke_flags |= KEF_EXIT;
|
|
}
|
|
thread_stopped(p);
|
|
thread_exit();
|
|
/* NOTREACHED */
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Either becomes an upcall or waits for an awakening event and
|
|
* then becomes an upcall. Only error cases return.
|
|
*/
|
|
/*
|
|
struct kse_release_args {
|
|
struct timespec *timeout;
|
|
};
|
|
*/
|
|
int
|
|
kse_release(struct thread *td, struct kse_release_args *uap)
|
|
{
|
|
struct proc *p;
|
|
struct ksegrp *kg;
|
|
struct timespec ts, ts2, ts3, timeout;
|
|
struct timeval tv;
|
|
int error;
|
|
|
|
p = td->td_proc;
|
|
kg = td->td_ksegrp;
|
|
if (td->td_upcall == NULL || TD_CAN_UNBIND(td))
|
|
return (EINVAL);
|
|
if (uap->timeout != NULL) {
|
|
if ((error = copyin(uap->timeout, &timeout, sizeof(timeout))))
|
|
return (error);
|
|
getnanouptime(&ts);
|
|
timespecadd(&ts, &timeout);
|
|
TIMESPEC_TO_TIMEVAL(&tv, &timeout);
|
|
}
|
|
mtx_lock_spin(&sched_lock);
|
|
/* Change OURSELF to become an upcall. */
|
|
td->td_flags = TDF_UPCALLING;
|
|
#if 0 /* XXX This shouldn't be necessary */
|
|
if (p->p_sflag & PS_NEEDSIGCHK)
|
|
td->td_flags |= TDF_ASTPENDING;
|
|
#endif
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_LOCK(p);
|
|
while ((td->td_upcall->ku_flags & KUF_DOUPCALL) == 0 &&
|
|
(kg->kg_completed == NULL)) {
|
|
kg->kg_upsleeps++;
|
|
error = msleep(&kg->kg_completed, &p->p_mtx, PPAUSE|PCATCH,
|
|
"kse_rel", (uap->timeout ? tvtohz(&tv) : 0));
|
|
kg->kg_upsleeps--;
|
|
PROC_UNLOCK(p);
|
|
if (uap->timeout == NULL || error != EWOULDBLOCK)
|
|
return (0);
|
|
getnanouptime(&ts2);
|
|
if (timespeccmp(&ts2, &ts, >=))
|
|
return (0);
|
|
ts3 = ts;
|
|
timespecsub(&ts3, &ts2);
|
|
TIMESPEC_TO_TIMEVAL(&tv, &ts3);
|
|
PROC_LOCK(p);
|
|
}
|
|
PROC_UNLOCK(p);
|
|
return (0);
|
|
}
|
|
|
|
/* struct kse_wakeup_args {
|
|
struct kse_mailbox *mbx;
|
|
}; */
|
|
int
|
|
kse_wakeup(struct thread *td, struct kse_wakeup_args *uap)
|
|
{
|
|
struct proc *p;
|
|
struct ksegrp *kg;
|
|
struct kse_upcall *ku;
|
|
struct thread *td2;
|
|
|
|
p = td->td_proc;
|
|
td2 = NULL;
|
|
ku = NULL;
|
|
/* KSE-enabled processes only, please. */
|
|
if (!(p->p_flag & P_THREADED))
|
|
return (EINVAL);
|
|
PROC_LOCK(p);
|
|
mtx_lock_spin(&sched_lock);
|
|
if (uap->mbx) {
|
|
FOREACH_KSEGRP_IN_PROC(p, kg) {
|
|
FOREACH_UPCALL_IN_GROUP(kg, ku) {
|
|
if (ku->ku_mailbox == uap->mbx)
|
|
break;
|
|
}
|
|
if (ku)
|
|
break;
|
|
}
|
|
} else {
|
|
kg = td->td_ksegrp;
|
|
if (kg->kg_upsleeps) {
|
|
wakeup_one(&kg->kg_completed);
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_UNLOCK(p);
|
|
return (0);
|
|
}
|
|
ku = TAILQ_FIRST(&kg->kg_upcalls);
|
|
}
|
|
if (ku) {
|
|
if ((td2 = ku->ku_owner) == NULL) {
|
|
panic("%s: no owner", __func__);
|
|
} else if (TD_ON_SLEEPQ(td2) &&
|
|
(td2->td_wchan == &kg->kg_completed)) {
|
|
abortsleep(td2);
|
|
} else {
|
|
ku->ku_flags |= KUF_DOUPCALL;
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_UNLOCK(p);
|
|
return (0);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_UNLOCK(p);
|
|
return (ESRCH);
|
|
}
|
|
|
|
/*
|
|
* No new KSEG: first call: use current KSE, don't schedule an upcall
|
|
* All other situations, do allocate max new KSEs and schedule an upcall.
|
|
*/
|
|
/* struct kse_create_args {
|
|
struct kse_mailbox *mbx;
|
|
int newgroup;
|
|
}; */
|
|
int
|
|
kse_create(struct thread *td, struct kse_create_args *uap)
|
|
{
|
|
struct kse *newke;
|
|
struct ksegrp *newkg;
|
|
struct ksegrp *kg;
|
|
struct proc *p;
|
|
struct kse_mailbox mbx;
|
|
struct kse_upcall *newku;
|
|
int err, ncpus;
|
|
|
|
p = td->td_proc;
|
|
if ((err = copyin(uap->mbx, &mbx, sizeof(mbx))))
|
|
return (err);
|
|
|
|
/* Too bad, why hasn't kernel always a cpu counter !? */
|
|
#ifdef SMP
|
|
ncpus = mp_ncpus;
|
|
#else
|
|
ncpus = 1;
|
|
#endif
|
|
if (thread_debug && virtual_cpu != 0)
|
|
ncpus = virtual_cpu;
|
|
|
|
/* Easier to just set it than to test and set */
|
|
PROC_LOCK(p);
|
|
p->p_flag |= P_THREADED;
|
|
PROC_UNLOCK(p);
|
|
kg = td->td_ksegrp;
|
|
if (uap->newgroup) {
|
|
/* Have race condition but it is cheap */
|
|
if (p->p_numksegrps >= max_groups_per_proc)
|
|
return (EPROCLIM);
|
|
/*
|
|
* If we want a new KSEGRP it doesn't matter whether
|
|
* we have already fired up KSE mode before or not.
|
|
* We put the process in KSE mode and create a new KSEGRP.
|
|
*/
|
|
newkg = ksegrp_alloc();
|
|
bzero(&newkg->kg_startzero, RANGEOF(struct ksegrp,
|
|
kg_startzero, kg_endzero));
|
|
bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
|
|
RANGEOF(struct ksegrp, kg_startcopy, kg_endcopy));
|
|
mtx_lock_spin(&sched_lock);
|
|
if (p->p_numksegrps >= max_groups_per_proc) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
ksegrp_free(newkg);
|
|
return (EPROCLIM);
|
|
}
|
|
ksegrp_link(newkg, p);
|
|
mtx_unlock_spin(&sched_lock);
|
|
} else {
|
|
newkg = kg;
|
|
}
|
|
|
|
/*
|
|
* Creating upcalls more than number of physical cpu does
|
|
* not help performance.
|
|
*/
|
|
if (newkg->kg_numupcalls >= ncpus)
|
|
return (EPROCLIM);
|
|
|
|
if (newkg->kg_numupcalls == 0) {
|
|
/*
|
|
* Initialize KSE group, optimized for MP.
|
|
* Create KSEs as many as physical cpus, this increases
|
|
* concurrent even if userland is not MP safe and can only run
|
|
* on single CPU (for early version of libpthread, it is true).
|
|
* In ideal world, every physical cpu should execute a thread.
|
|
* If there is enough KSEs, threads in kernel can be
|
|
* executed parallel on different cpus with full speed,
|
|
* Concurrent in kernel shouldn't be restricted by number of
|
|
* upcalls userland provides.
|
|
* Adding more upcall structures only increases concurrent
|
|
* in userland.
|
|
* Highest performance configuration is:
|
|
* N kses = N upcalls = N phyiscal cpus
|
|
*/
|
|
while (newkg->kg_kses < ncpus) {
|
|
newke = kse_alloc();
|
|
bzero(&newke->ke_startzero, RANGEOF(struct kse,
|
|
ke_startzero, ke_endzero));
|
|
#if 0
|
|
mtx_lock_spin(&sched_lock);
|
|
bcopy(&ke->ke_startcopy, &newke->ke_startcopy,
|
|
RANGEOF(struct kse, ke_startcopy, ke_endcopy));
|
|
mtx_unlock_spin(&sched_lock);
|
|
#endif
|
|
mtx_lock_spin(&sched_lock);
|
|
kse_link(newke, newkg);
|
|
/* Add engine */
|
|
kse_reassign(newke);
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
}
|
|
newku = upcall_alloc();
|
|
newku->ku_mailbox = uap->mbx;
|
|
newku->ku_func = mbx.km_func;
|
|
bcopy(&mbx.km_stack, &newku->ku_stack, sizeof(stack_t));
|
|
|
|
/* For the first call this may not have been set */
|
|
if (td->td_standin == NULL)
|
|
thread_alloc_spare(td, NULL);
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
if (newkg->kg_numupcalls >= ncpus) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
upcall_free(newku);
|
|
return (EPROCLIM);
|
|
}
|
|
upcall_link(newku, newkg);
|
|
if (mbx.km_quantum)
|
|
newkg->kg_upquantum = max(1, mbx.km_quantum/tick);
|
|
|
|
/*
|
|
* Each upcall structure has an owner thread, find which
|
|
* one owns it.
|
|
*/
|
|
if (uap->newgroup) {
|
|
/*
|
|
* Because new ksegrp hasn't thread,
|
|
* create an initial upcall thread to own it.
|
|
*/
|
|
thread_schedule_upcall(td, newku);
|
|
} else {
|
|
/*
|
|
* If current thread hasn't an upcall structure,
|
|
* just assign the upcall to it.
|
|
*/
|
|
if (td->td_upcall == NULL) {
|
|
newku->ku_owner = td;
|
|
td->td_upcall = newku;
|
|
} else {
|
|
/*
|
|
* Create a new upcall thread to own it.
|
|
*/
|
|
thread_schedule_upcall(td, newku);
|
|
}
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Fill a ucontext_t with a thread's context information.
|
|
*
|
|
* This is an analogue to getcontext(3).
|
|
*/
|
|
void
|
|
thread_getcontext(struct thread *td, ucontext_t *uc)
|
|
{
|
|
|
|
get_mcontext(td, &uc->uc_mcontext, 0);
|
|
PROC_LOCK(td->td_proc);
|
|
uc->uc_sigmask = td->td_sigmask;
|
|
PROC_UNLOCK(td->td_proc);
|
|
}
|
|
|
|
/*
|
|
* Set a thread's context from a ucontext_t.
|
|
*
|
|
* This is an analogue to setcontext(3).
|
|
*/
|
|
int
|
|
thread_setcontext(struct thread *td, ucontext_t *uc)
|
|
{
|
|
int ret;
|
|
|
|
ret = set_mcontext(td, &uc->uc_mcontext);
|
|
if (ret == 0) {
|
|
SIG_CANTMASK(uc->uc_sigmask);
|
|
PROC_LOCK(td->td_proc);
|
|
td->td_sigmask = uc->uc_sigmask;
|
|
PROC_UNLOCK(td->td_proc);
|
|
}
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* Initialize global thread allocation resources.
|
|
*/
|
|
void
|
|
threadinit(void)
|
|
{
|
|
|
|
#ifndef __ia64__
|
|
thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(),
|
|
thread_ctor, thread_dtor, thread_init, thread_fini,
|
|
UMA_ALIGN_CACHE, 0);
|
|
#else
|
|
/*
|
|
* XXX the ia64 kstack allocator is really lame and is at the mercy
|
|
* of contigmallloc(). This hackery is to pre-construct a whole
|
|
* pile of thread structures with associated kernel stacks early
|
|
* in the system startup while contigmalloc() still works. Once we
|
|
* have them, keep them. Sigh.
|
|
*/
|
|
thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(),
|
|
thread_ctor, thread_dtor, thread_init, thread_fini,
|
|
UMA_ALIGN_CACHE, UMA_ZONE_NOFREE);
|
|
uma_prealloc(thread_zone, 512); /* XXX arbitary */
|
|
#endif
|
|
ksegrp_zone = uma_zcreate("KSEGRP", sched_sizeof_ksegrp(),
|
|
NULL, NULL, ksegrp_init, NULL,
|
|
UMA_ALIGN_CACHE, 0);
|
|
kse_zone = uma_zcreate("KSE", sched_sizeof_kse(),
|
|
NULL, NULL, kse_init, NULL,
|
|
UMA_ALIGN_CACHE, 0);
|
|
upcall_zone = uma_zcreate("UPCALL", sizeof(struct kse_upcall),
|
|
NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
|
|
}
|
|
|
|
/*
|
|
* Stash an embarasingly extra thread into the zombie thread queue.
|
|
*/
|
|
void
|
|
thread_stash(struct thread *td)
|
|
{
|
|
mtx_lock_spin(&kse_zombie_lock);
|
|
TAILQ_INSERT_HEAD(&zombie_threads, td, td_runq);
|
|
mtx_unlock_spin(&kse_zombie_lock);
|
|
}
|
|
|
|
/*
|
|
* Stash an embarasingly extra kse into the zombie kse queue.
|
|
*/
|
|
void
|
|
kse_stash(struct kse *ke)
|
|
{
|
|
mtx_lock_spin(&kse_zombie_lock);
|
|
TAILQ_INSERT_HEAD(&zombie_kses, ke, ke_procq);
|
|
mtx_unlock_spin(&kse_zombie_lock);
|
|
}
|
|
|
|
/*
|
|
* Stash an embarasingly extra upcall into the zombie upcall queue.
|
|
*/
|
|
|
|
void
|
|
upcall_stash(struct kse_upcall *ku)
|
|
{
|
|
mtx_lock_spin(&kse_zombie_lock);
|
|
TAILQ_INSERT_HEAD(&zombie_upcalls, ku, ku_link);
|
|
mtx_unlock_spin(&kse_zombie_lock);
|
|
}
|
|
|
|
/*
|
|
* Stash an embarasingly extra ksegrp into the zombie ksegrp queue.
|
|
*/
|
|
void
|
|
ksegrp_stash(struct ksegrp *kg)
|
|
{
|
|
mtx_lock_spin(&kse_zombie_lock);
|
|
TAILQ_INSERT_HEAD(&zombie_ksegrps, kg, kg_ksegrp);
|
|
mtx_unlock_spin(&kse_zombie_lock);
|
|
}
|
|
|
|
/*
|
|
* Reap zombie kse resource.
|
|
*/
|
|
void
|
|
thread_reap(void)
|
|
{
|
|
struct thread *td_first, *td_next;
|
|
struct kse *ke_first, *ke_next;
|
|
struct ksegrp *kg_first, * kg_next;
|
|
struct kse_upcall *ku_first, *ku_next;
|
|
|
|
/*
|
|
* Don't even bother to lock if none at this instant,
|
|
* we really don't care about the next instant..
|
|
*/
|
|
if ((!TAILQ_EMPTY(&zombie_threads))
|
|
|| (!TAILQ_EMPTY(&zombie_kses))
|
|
|| (!TAILQ_EMPTY(&zombie_ksegrps))
|
|
|| (!TAILQ_EMPTY(&zombie_upcalls))) {
|
|
mtx_lock_spin(&kse_zombie_lock);
|
|
td_first = TAILQ_FIRST(&zombie_threads);
|
|
ke_first = TAILQ_FIRST(&zombie_kses);
|
|
kg_first = TAILQ_FIRST(&zombie_ksegrps);
|
|
ku_first = TAILQ_FIRST(&zombie_upcalls);
|
|
if (td_first)
|
|
TAILQ_INIT(&zombie_threads);
|
|
if (ke_first)
|
|
TAILQ_INIT(&zombie_kses);
|
|
if (kg_first)
|
|
TAILQ_INIT(&zombie_ksegrps);
|
|
if (ku_first)
|
|
TAILQ_INIT(&zombie_upcalls);
|
|
mtx_unlock_spin(&kse_zombie_lock);
|
|
while (td_first) {
|
|
td_next = TAILQ_NEXT(td_first, td_runq);
|
|
if (td_first->td_ucred)
|
|
crfree(td_first->td_ucred);
|
|
thread_free(td_first);
|
|
td_first = td_next;
|
|
}
|
|
while (ke_first) {
|
|
ke_next = TAILQ_NEXT(ke_first, ke_procq);
|
|
kse_free(ke_first);
|
|
ke_first = ke_next;
|
|
}
|
|
while (kg_first) {
|
|
kg_next = TAILQ_NEXT(kg_first, kg_ksegrp);
|
|
ksegrp_free(kg_first);
|
|
kg_first = kg_next;
|
|
}
|
|
while (ku_first) {
|
|
ku_next = TAILQ_NEXT(ku_first, ku_link);
|
|
upcall_free(ku_first);
|
|
ku_first = ku_next;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Allocate a ksegrp.
|
|
*/
|
|
struct ksegrp *
|
|
ksegrp_alloc(void)
|
|
{
|
|
return (uma_zalloc(ksegrp_zone, M_WAITOK));
|
|
}
|
|
|
|
/*
|
|
* Allocate a kse.
|
|
*/
|
|
struct kse *
|
|
kse_alloc(void)
|
|
{
|
|
return (uma_zalloc(kse_zone, M_WAITOK));
|
|
}
|
|
|
|
/*
|
|
* Allocate a thread.
|
|
*/
|
|
struct thread *
|
|
thread_alloc(void)
|
|
{
|
|
thread_reap(); /* check if any zombies to get */
|
|
return (uma_zalloc(thread_zone, M_WAITOK));
|
|
}
|
|
|
|
/*
|
|
* Deallocate a ksegrp.
|
|
*/
|
|
void
|
|
ksegrp_free(struct ksegrp *td)
|
|
{
|
|
uma_zfree(ksegrp_zone, td);
|
|
}
|
|
|
|
/*
|
|
* Deallocate a kse.
|
|
*/
|
|
void
|
|
kse_free(struct kse *td)
|
|
{
|
|
uma_zfree(kse_zone, td);
|
|
}
|
|
|
|
/*
|
|
* Deallocate a thread.
|
|
*/
|
|
void
|
|
thread_free(struct thread *td)
|
|
{
|
|
|
|
cpu_thread_clean(td);
|
|
uma_zfree(thread_zone, td);
|
|
}
|
|
|
|
/*
|
|
* Store the thread context in the UTS's mailbox.
|
|
* then add the mailbox at the head of a list we are building in user space.
|
|
* The list is anchored in the ksegrp structure.
|
|
*/
|
|
int
|
|
thread_export_context(struct thread *td)
|
|
{
|
|
struct proc *p;
|
|
struct ksegrp *kg;
|
|
uintptr_t mbx;
|
|
void *addr;
|
|
int error,temp;
|
|
ucontext_t uc;
|
|
|
|
p = td->td_proc;
|
|
kg = td->td_ksegrp;
|
|
|
|
/* Export the user/machine context. */
|
|
addr = (void *)(&td->td_mailbox->tm_context);
|
|
error = copyin(addr, &uc, sizeof(ucontext_t));
|
|
if (error)
|
|
goto bad;
|
|
|
|
thread_getcontext(td, &uc);
|
|
error = copyout(&uc, addr, sizeof(ucontext_t));
|
|
if (error)
|
|
goto bad;
|
|
|
|
/* Exports clock ticks in kernel mode */
|
|
addr = (caddr_t)(&td->td_mailbox->tm_sticks);
|
|
temp = fuword(addr) + td->td_usticks;
|
|
if (suword(addr, temp))
|
|
goto bad;
|
|
|
|
/* Get address in latest mbox of list pointer */
|
|
addr = (void *)(&td->td_mailbox->tm_next);
|
|
/*
|
|
* Put the saved address of the previous first
|
|
* entry into this one
|
|
*/
|
|
for (;;) {
|
|
mbx = (uintptr_t)kg->kg_completed;
|
|
if (suword(addr, mbx)) {
|
|
error = EFAULT;
|
|
goto bad;
|
|
}
|
|
PROC_LOCK(p);
|
|
if (mbx == (uintptr_t)kg->kg_completed) {
|
|
kg->kg_completed = td->td_mailbox;
|
|
/*
|
|
* The thread context may be taken away by
|
|
* other upcall threads when we unlock
|
|
* process lock. it's no longer valid to
|
|
* use it again in any other places.
|
|
*/
|
|
td->td_mailbox = NULL;
|
|
PROC_UNLOCK(p);
|
|
break;
|
|
}
|
|
PROC_UNLOCK(p);
|
|
}
|
|
td->td_usticks = 0;
|
|
return (0);
|
|
|
|
bad:
|
|
PROC_LOCK(p);
|
|
psignal(p, SIGSEGV);
|
|
PROC_UNLOCK(p);
|
|
/* The mailbox is bad, don't use it */
|
|
td->td_mailbox = NULL;
|
|
td->td_usticks = 0;
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Take the list of completed mailboxes for this KSEGRP and put them on this
|
|
* upcall's mailbox as it's the next one going up.
|
|
*/
|
|
static int
|
|
thread_link_mboxes(struct ksegrp *kg, struct kse_upcall *ku)
|
|
{
|
|
struct proc *p = kg->kg_proc;
|
|
void *addr;
|
|
uintptr_t mbx;
|
|
|
|
addr = (void *)(&ku->ku_mailbox->km_completed);
|
|
for (;;) {
|
|
mbx = (uintptr_t)kg->kg_completed;
|
|
if (suword(addr, mbx)) {
|
|
PROC_LOCK(p);
|
|
psignal(p, SIGSEGV);
|
|
PROC_UNLOCK(p);
|
|
return (EFAULT);
|
|
}
|
|
PROC_LOCK(p);
|
|
if (mbx == (uintptr_t)kg->kg_completed) {
|
|
kg->kg_completed = NULL;
|
|
PROC_UNLOCK(p);
|
|
break;
|
|
}
|
|
PROC_UNLOCK(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* This function should be called at statclock interrupt time
|
|
*/
|
|
int
|
|
thread_statclock(int user)
|
|
{
|
|
struct thread *td = curthread;
|
|
|
|
if (td->td_ksegrp->kg_numupcalls == 0)
|
|
return (-1);
|
|
if (user) {
|
|
/* Current always do via ast() */
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_flags |= (TDF_USTATCLOCK|TDF_ASTPENDING);
|
|
mtx_unlock_spin(&sched_lock);
|
|
td->td_uuticks++;
|
|
} else {
|
|
if (td->td_mailbox != NULL)
|
|
td->td_usticks++;
|
|
else {
|
|
/* XXXKSE
|
|
* We will call thread_user_enter() for every
|
|
* kernel entry in future, so if the thread mailbox
|
|
* is NULL, it must be a UTS kernel, don't account
|
|
* clock ticks for it.
|
|
*/
|
|
}
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Export state clock ticks for userland
|
|
*/
|
|
static int
|
|
thread_update_usr_ticks(struct thread *td, int user)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
struct kse_thr_mailbox *tmbx;
|
|
struct kse_upcall *ku;
|
|
struct ksegrp *kg;
|
|
caddr_t addr;
|
|
uint uticks;
|
|
|
|
if ((ku = td->td_upcall) == NULL)
|
|
return (-1);
|
|
|
|
tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread);
|
|
if ((tmbx == NULL) || (tmbx == (void *)-1))
|
|
return (-1);
|
|
if (user) {
|
|
uticks = td->td_uuticks;
|
|
td->td_uuticks = 0;
|
|
addr = (caddr_t)&tmbx->tm_uticks;
|
|
} else {
|
|
uticks = td->td_usticks;
|
|
td->td_usticks = 0;
|
|
addr = (caddr_t)&tmbx->tm_sticks;
|
|
}
|
|
if (uticks) {
|
|
if (suword(addr, uticks+fuword(addr))) {
|
|
PROC_LOCK(p);
|
|
psignal(p, SIGSEGV);
|
|
PROC_UNLOCK(p);
|
|
return (-2);
|
|
}
|
|
}
|
|
kg = td->td_ksegrp;
|
|
if (kg->kg_upquantum && ticks >= kg->kg_nextupcall) {
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_upcall->ku_flags |= KUF_DOUPCALL;
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Discard the current thread and exit from its context.
|
|
*
|
|
* Because we can't free a thread while we're operating under its context,
|
|
* push the current thread into our CPU's deadthread holder. This means
|
|
* we needn't worry about someone else grabbing our context before we
|
|
* do a cpu_throw().
|
|
*/
|
|
void
|
|
thread_exit(void)
|
|
{
|
|
struct thread *td;
|
|
struct kse *ke;
|
|
struct proc *p;
|
|
struct ksegrp *kg;
|
|
|
|
td = curthread;
|
|
kg = td->td_ksegrp;
|
|
p = td->td_proc;
|
|
ke = td->td_kse;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
KASSERT(p != NULL, ("thread exiting without a process"));
|
|
KASSERT(ke != NULL, ("thread exiting without a kse"));
|
|
KASSERT(kg != NULL, ("thread exiting without a kse group"));
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
CTR1(KTR_PROC, "thread_exit: thread %p", td);
|
|
KASSERT(!mtx_owned(&Giant), ("dying thread owns giant"));
|
|
|
|
if (td->td_standin != NULL) {
|
|
thread_stash(td->td_standin);
|
|
td->td_standin = NULL;
|
|
}
|
|
|
|
cpu_thread_exit(td); /* XXXSMP */
|
|
|
|
/*
|
|
* The last thread is left attached to the process
|
|
* So that the whole bundle gets recycled. Skip
|
|
* all this stuff.
|
|
*/
|
|
if (p->p_numthreads > 1) {
|
|
thread_unlink(td);
|
|
if (p->p_maxthrwaits)
|
|
wakeup(&p->p_numthreads);
|
|
/*
|
|
* The test below is NOT true if we are the
|
|
* sole exiting thread. P_STOPPED_SNGL is unset
|
|
* in exit1() after it is the only survivor.
|
|
*/
|
|
if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
|
|
if (p->p_numthreads == p->p_suspcount) {
|
|
thread_unsuspend_one(p->p_singlethread);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Because each upcall structure has an owner thread,
|
|
* owner thread exits only when process is in exiting
|
|
* state, so upcall to userland is no longer needed,
|
|
* deleting upcall structure is safe here.
|
|
* So when all threads in a group is exited, all upcalls
|
|
* in the group should be automatically freed.
|
|
*/
|
|
if (td->td_upcall)
|
|
upcall_remove(td);
|
|
|
|
ke->ke_state = KES_UNQUEUED;
|
|
ke->ke_thread = NULL;
|
|
/*
|
|
* Decide what to do with the KSE attached to this thread.
|
|
*/
|
|
if (ke->ke_flags & KEF_EXIT)
|
|
kse_unlink(ke);
|
|
else
|
|
kse_reassign(ke);
|
|
PROC_UNLOCK(p);
|
|
td->td_kse = NULL;
|
|
td->td_state = TDS_INACTIVE;
|
|
#if 0
|
|
td->td_proc = NULL;
|
|
#endif
|
|
td->td_ksegrp = NULL;
|
|
td->td_last_kse = NULL;
|
|
PCPU_SET(deadthread, td);
|
|
} else {
|
|
PROC_UNLOCK(p);
|
|
}
|
|
/* XXX Shouldn't cpu_throw() here. */
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
#if !defined(__alpha__) && !defined(__powerpc__)
|
|
cpu_throw(td, choosethread());
|
|
#else
|
|
cpu_throw();
|
|
#endif
|
|
panic("I'm a teapot!");
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
/*
|
|
* Do any thread specific cleanups that may be needed in wait()
|
|
* called with Giant held, proc and schedlock not held.
|
|
*/
|
|
void
|
|
thread_wait(struct proc *p)
|
|
{
|
|
struct thread *td;
|
|
|
|
KASSERT((p->p_numthreads == 1), ("Muliple threads in wait1()"));
|
|
KASSERT((p->p_numksegrps == 1), ("Muliple ksegrps in wait1()"));
|
|
FOREACH_THREAD_IN_PROC(p, td) {
|
|
if (td->td_standin != NULL) {
|
|
thread_free(td->td_standin);
|
|
td->td_standin = NULL;
|
|
}
|
|
cpu_thread_clean(td);
|
|
}
|
|
thread_reap(); /* check for zombie threads etc. */
|
|
}
|
|
|
|
/*
|
|
* Link a thread to a process.
|
|
* set up anything that needs to be initialized for it to
|
|
* be used by the process.
|
|
*
|
|
* Note that we do not link to the proc's ucred here.
|
|
* The thread is linked as if running but no KSE assigned.
|
|
*/
|
|
void
|
|
thread_link(struct thread *td, struct ksegrp *kg)
|
|
{
|
|
struct proc *p;
|
|
|
|
p = kg->kg_proc;
|
|
td->td_state = TDS_INACTIVE;
|
|
td->td_proc = p;
|
|
td->td_ksegrp = kg;
|
|
td->td_last_kse = NULL;
|
|
td->td_flags = 0;
|
|
td->td_kse = NULL;
|
|
|
|
LIST_INIT(&td->td_contested);
|
|
callout_init(&td->td_slpcallout, 1);
|
|
TAILQ_INSERT_HEAD(&p->p_threads, td, td_plist);
|
|
TAILQ_INSERT_HEAD(&kg->kg_threads, td, td_kglist);
|
|
p->p_numthreads++;
|
|
kg->kg_numthreads++;
|
|
}
|
|
|
|
void
|
|
thread_unlink(struct thread *td)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
struct ksegrp *kg = td->td_ksegrp;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
TAILQ_REMOVE(&p->p_threads, td, td_plist);
|
|
p->p_numthreads--;
|
|
TAILQ_REMOVE(&kg->kg_threads, td, td_kglist);
|
|
kg->kg_numthreads--;
|
|
/* could clear a few other things here */
|
|
}
|
|
|
|
/*
|
|
* Purge a ksegrp resource. When a ksegrp is preparing to
|
|
* exit, it calls this function.
|
|
*/
|
|
static void
|
|
kse_purge_group(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
struct kse *ke;
|
|
|
|
kg = td->td_ksegrp;
|
|
KASSERT(kg->kg_numthreads == 1, ("%s: bad thread number", __func__));
|
|
while ((ke = TAILQ_FIRST(&kg->kg_iq)) != NULL) {
|
|
KASSERT(ke->ke_state == KES_IDLE,
|
|
("%s: wrong idle KSE state", __func__));
|
|
kse_unlink(ke);
|
|
}
|
|
KASSERT((kg->kg_kses == 1),
|
|
("%s: ksegrp still has %d KSEs", __func__, kg->kg_kses));
|
|
KASSERT((kg->kg_numupcalls == 0),
|
|
("%s: ksegrp still has %d upcall datas",
|
|
__func__, kg->kg_numupcalls));
|
|
}
|
|
|
|
/*
|
|
* Purge a process's KSE resource. When a process is preparing to
|
|
* exit, it calls kse_purge to release any extra KSE resources in
|
|
* the process.
|
|
*/
|
|
static void
|
|
kse_purge(struct proc *p, struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
struct kse *ke;
|
|
|
|
KASSERT(p->p_numthreads == 1, ("bad thread number"));
|
|
while ((kg = TAILQ_FIRST(&p->p_ksegrps)) != NULL) {
|
|
TAILQ_REMOVE(&p->p_ksegrps, kg, kg_ksegrp);
|
|
p->p_numksegrps--;
|
|
/*
|
|
* There is no ownership for KSE, after all threads
|
|
* in the group exited, it is possible that some KSEs
|
|
* were left in idle queue, gc them now.
|
|
*/
|
|
while ((ke = TAILQ_FIRST(&kg->kg_iq)) != NULL) {
|
|
KASSERT(ke->ke_state == KES_IDLE,
|
|
("%s: wrong idle KSE state", __func__));
|
|
TAILQ_REMOVE(&kg->kg_iq, ke, ke_kgrlist);
|
|
kg->kg_idle_kses--;
|
|
TAILQ_REMOVE(&kg->kg_kseq, ke, ke_kglist);
|
|
kg->kg_kses--;
|
|
kse_stash(ke);
|
|
}
|
|
KASSERT(((kg->kg_kses == 0) && (kg != td->td_ksegrp)) ||
|
|
((kg->kg_kses == 1) && (kg == td->td_ksegrp)),
|
|
("ksegrp has wrong kg_kses: %d", kg->kg_kses));
|
|
KASSERT((kg->kg_numupcalls == 0),
|
|
("%s: ksegrp still has %d upcall datas",
|
|
__func__, kg->kg_numupcalls));
|
|
|
|
if (kg != td->td_ksegrp)
|
|
ksegrp_stash(kg);
|
|
}
|
|
TAILQ_INSERT_HEAD(&p->p_ksegrps, td->td_ksegrp, kg_ksegrp);
|
|
p->p_numksegrps++;
|
|
}
|
|
|
|
/*
|
|
* This function is intended to be used to initialize a spare thread
|
|
* for upcall. Initialize thread's large data area outside sched_lock
|
|
* for thread_schedule_upcall().
|
|
*/
|
|
void
|
|
thread_alloc_spare(struct thread *td, struct thread *spare)
|
|
{
|
|
if (td->td_standin)
|
|
return;
|
|
if (spare == NULL)
|
|
spare = thread_alloc();
|
|
td->td_standin = spare;
|
|
bzero(&spare->td_startzero,
|
|
(unsigned)RANGEOF(struct thread, td_startzero, td_endzero));
|
|
spare->td_proc = td->td_proc;
|
|
spare->td_ucred = crhold(td->td_ucred);
|
|
}
|
|
|
|
/*
|
|
* Create a thread and schedule it for upcall on the KSE given.
|
|
* Use our thread's standin so that we don't have to allocate one.
|
|
*/
|
|
struct thread *
|
|
thread_schedule_upcall(struct thread *td, struct kse_upcall *ku)
|
|
{
|
|
struct thread *td2;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
|
|
/*
|
|
* Schedule an upcall thread on specified kse_upcall,
|
|
* the kse_upcall must be free.
|
|
* td must have a spare thread.
|
|
*/
|
|
KASSERT(ku->ku_owner == NULL, ("%s: upcall has owner", __func__));
|
|
if ((td2 = td->td_standin) != NULL) {
|
|
td->td_standin = NULL;
|
|
} else {
|
|
panic("no reserve thread when scheduling an upcall");
|
|
return (NULL);
|
|
}
|
|
CTR3(KTR_PROC, "thread_schedule_upcall: thread %p (pid %d, %s)",
|
|
td2, td->td_proc->p_pid, td->td_proc->p_comm);
|
|
bcopy(&td->td_startcopy, &td2->td_startcopy,
|
|
(unsigned) RANGEOF(struct thread, td_startcopy, td_endcopy));
|
|
thread_link(td2, ku->ku_ksegrp);
|
|
/* inherit blocked thread's context */
|
|
bcopy(td->td_frame, td2->td_frame, sizeof(struct trapframe));
|
|
cpu_set_upcall(td2, td->td_pcb);
|
|
/* Let the new thread become owner of the upcall */
|
|
ku->ku_owner = td2;
|
|
td2->td_upcall = ku;
|
|
td2->td_flags = TDF_UPCALLING;
|
|
#if 0 /* XXX This shouldn't be necessary */
|
|
if (td->td_proc->p_sflag & PS_NEEDSIGCHK)
|
|
td2->td_flags |= TDF_ASTPENDING;
|
|
#endif
|
|
td2->td_kse = NULL;
|
|
td2->td_state = TDS_CAN_RUN;
|
|
td2->td_inhibitors = 0;
|
|
setrunqueue(td2);
|
|
return (td2); /* bogus.. should be a void function */
|
|
}
|
|
|
|
void
|
|
thread_signal_add(struct thread *td, int sig)
|
|
{
|
|
struct kse_upcall *ku;
|
|
struct proc *p;
|
|
sigset_t ss;
|
|
int error;
|
|
|
|
PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
|
|
td = curthread;
|
|
ku = td->td_upcall;
|
|
p = td->td_proc;
|
|
|
|
PROC_UNLOCK(p);
|
|
error = copyin(&ku->ku_mailbox->km_sigscaught, &ss, sizeof(sigset_t));
|
|
if (error)
|
|
goto error;
|
|
|
|
SIGADDSET(ss, sig);
|
|
|
|
error = copyout(&ss, &ku->ku_mailbox->km_sigscaught, sizeof(sigset_t));
|
|
if (error)
|
|
goto error;
|
|
|
|
PROC_LOCK(p);
|
|
return;
|
|
error:
|
|
PROC_LOCK(p);
|
|
sigexit(td, SIGILL);
|
|
}
|
|
|
|
|
|
/*
|
|
* Schedule an upcall to notify a KSE process recieved signals.
|
|
*
|
|
*/
|
|
void
|
|
thread_signal_upcall(struct thread *td)
|
|
{
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_flags |= TDF_UPCALLING;
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
return;
|
|
}
|
|
|
|
void
|
|
thread_switchout(struct thread *td)
|
|
{
|
|
struct kse_upcall *ku;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
|
|
/*
|
|
* If the outgoing thread is in threaded group and has never
|
|
* scheduled an upcall, decide whether this is a short
|
|
* or long term event and thus whether or not to schedule
|
|
* an upcall.
|
|
* If it is a short term event, just suspend it in
|
|
* a way that takes its KSE with it.
|
|
* Select the events for which we want to schedule upcalls.
|
|
* For now it's just sleep.
|
|
* XXXKSE eventually almost any inhibition could do.
|
|
*/
|
|
if (TD_CAN_UNBIND(td) && (td->td_standin) && TD_ON_SLEEPQ(td)) {
|
|
/*
|
|
* Release ownership of upcall, and schedule an upcall
|
|
* thread, this new upcall thread becomes the owner of
|
|
* the upcall structure.
|
|
*/
|
|
ku = td->td_upcall;
|
|
ku->ku_owner = NULL;
|
|
td->td_upcall = NULL;
|
|
td->td_flags &= ~TDF_CAN_UNBIND;
|
|
thread_schedule_upcall(td, ku);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Setup done on the thread when it enters the kernel.
|
|
* XXXKSE Presently only for syscalls but eventually all kernel entries.
|
|
*/
|
|
void
|
|
thread_user_enter(struct proc *p, struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
struct kse_upcall *ku;
|
|
struct kse_thr_mailbox *tmbx;
|
|
|
|
kg = td->td_ksegrp;
|
|
|
|
/*
|
|
* First check that we shouldn't just abort.
|
|
* But check if we are the single thread first!
|
|
*/
|
|
PROC_LOCK(p);
|
|
if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) {
|
|
mtx_lock_spin(&sched_lock);
|
|
thread_stopped(p);
|
|
thread_exit();
|
|
/* NOTREACHED */
|
|
}
|
|
PROC_UNLOCK(p);
|
|
|
|
/*
|
|
* If we are doing a syscall in a KSE environment,
|
|
* note where our mailbox is. There is always the
|
|
* possibility that we could do this lazily (in kse_reassign()),
|
|
* but for now do it every time.
|
|
*/
|
|
kg = td->td_ksegrp;
|
|
if (kg->kg_numupcalls) {
|
|
ku = td->td_upcall;
|
|
KASSERT(ku, ("%s: no upcall owned", __func__));
|
|
KASSERT((ku->ku_owner == td), ("%s: wrong owner", __func__));
|
|
KASSERT(!TD_CAN_UNBIND(td), ("%s: can unbind", __func__));
|
|
ku->ku_mflags = fuword((void *)&ku->ku_mailbox->km_flags);
|
|
tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread);
|
|
if ((tmbx == NULL) || (tmbx == (void *)-1)) {
|
|
td->td_mailbox = NULL;
|
|
} else {
|
|
td->td_mailbox = tmbx;
|
|
if (td->td_standin == NULL)
|
|
thread_alloc_spare(td, NULL);
|
|
mtx_lock_spin(&sched_lock);
|
|
if (ku->ku_mflags & KMF_NOUPCALL)
|
|
td->td_flags &= ~TDF_CAN_UNBIND;
|
|
else
|
|
td->td_flags |= TDF_CAN_UNBIND;
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The extra work we go through if we are a threaded process when we
|
|
* return to userland.
|
|
*
|
|
* If we are a KSE process and returning to user mode, check for
|
|
* extra work to do before we return (e.g. for more syscalls
|
|
* to complete first). If we were in a critical section, we should
|
|
* just return to let it finish. Same if we were in the UTS (in
|
|
* which case the mailbox's context's busy indicator will be set).
|
|
* The only traps we suport will have set the mailbox.
|
|
* We will clear it here.
|
|
*/
|
|
int
|
|
thread_userret(struct thread *td, struct trapframe *frame)
|
|
{
|
|
int error = 0, upcalls, uts_crit;
|
|
struct kse_upcall *ku;
|
|
struct ksegrp *kg, *kg2;
|
|
struct proc *p;
|
|
struct timespec ts;
|
|
|
|
p = td->td_proc;
|
|
kg = td->td_ksegrp;
|
|
|
|
/* Nothing to do with non-threaded group/process */
|
|
if (td->td_ksegrp->kg_numupcalls == 0)
|
|
return (0);
|
|
|
|
/*
|
|
* Stat clock interrupt hit in userland, it
|
|
* is returning from interrupt, charge thread's
|
|
* userland time for UTS.
|
|
*/
|
|
if (td->td_flags & TDF_USTATCLOCK) {
|
|
thread_update_usr_ticks(td, 1);
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_flags &= ~TDF_USTATCLOCK;
|
|
mtx_unlock_spin(&sched_lock);
|
|
if (kg->kg_completed ||
|
|
(td->td_upcall->ku_flags & KUF_DOUPCALL))
|
|
thread_user_enter(p, td);
|
|
}
|
|
|
|
uts_crit = (td->td_mailbox == NULL);
|
|
ku = td->td_upcall;
|
|
/*
|
|
* Optimisation:
|
|
* This thread has not started any upcall.
|
|
* If there is no work to report other than ourself,
|
|
* then it can return direct to userland.
|
|
*/
|
|
if (TD_CAN_UNBIND(td)) {
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_flags &= ~TDF_CAN_UNBIND;
|
|
if ((td->td_flags & TDF_NEEDSIGCHK) == 0 &&
|
|
(kg->kg_completed == NULL) &&
|
|
(ku->ku_flags & KUF_DOUPCALL) == 0 &&
|
|
(kg->kg_upquantum && ticks < kg->kg_nextupcall)) {
|
|
mtx_unlock_spin(&sched_lock);
|
|
thread_update_usr_ticks(td, 0);
|
|
nanotime(&ts);
|
|
error = copyout(&ts,
|
|
(caddr_t)&ku->ku_mailbox->km_timeofday,
|
|
sizeof(ts));
|
|
td->td_mailbox = 0;
|
|
ku->ku_mflags = 0;
|
|
if (error)
|
|
goto out;
|
|
return (0);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
error = thread_export_context(td);
|
|
if (error) {
|
|
/*
|
|
* Failing to do the KSE operation just defaults
|
|
* back to synchonous operation, so just return from
|
|
* the syscall.
|
|
*/
|
|
goto out;
|
|
}
|
|
/*
|
|
* There is something to report, and we own an upcall
|
|
* strucuture, we can go to userland.
|
|
* Turn ourself into an upcall thread.
|
|
*/
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_flags |= TDF_UPCALLING;
|
|
mtx_unlock_spin(&sched_lock);
|
|
} else if (td->td_mailbox && (ku == NULL)) {
|
|
error = thread_export_context(td);
|
|
/* possibly upcall with error? */
|
|
PROC_LOCK(p);
|
|
/*
|
|
* There are upcall threads waiting for
|
|
* work to do, wake one of them up.
|
|
* XXXKSE Maybe wake all of them up.
|
|
*/
|
|
if (!error && kg->kg_upsleeps)
|
|
wakeup_one(&kg->kg_completed);
|
|
mtx_lock_spin(&sched_lock);
|
|
thread_stopped(p);
|
|
thread_exit();
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
KASSERT(TD_CAN_UNBIND(td) == 0, ("can unbind"));
|
|
|
|
if (p->p_numthreads > max_threads_per_proc) {
|
|
max_threads_hits++;
|
|
PROC_LOCK(p);
|
|
mtx_lock_spin(&sched_lock);
|
|
while (p->p_numthreads > max_threads_per_proc) {
|
|
if (P_SHOULDSTOP(p))
|
|
break;
|
|
upcalls = 0;
|
|
FOREACH_KSEGRP_IN_PROC(p, kg2) {
|
|
if (kg2->kg_numupcalls == 0)
|
|
upcalls++;
|
|
else
|
|
upcalls += kg2->kg_numupcalls;
|
|
}
|
|
if (upcalls >= max_threads_per_proc)
|
|
break;
|
|
mtx_unlock_spin(&sched_lock);
|
|
p->p_maxthrwaits++;
|
|
msleep(&p->p_numthreads, &p->p_mtx, PPAUSE|PCATCH,
|
|
"maxthreads", NULL);
|
|
p->p_maxthrwaits--;
|
|
mtx_lock_spin(&sched_lock);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
|
|
if (td->td_flags & TDF_UPCALLING) {
|
|
uts_crit = 0;
|
|
kg->kg_nextupcall = ticks+kg->kg_upquantum;
|
|
/*
|
|
* There is no more work to do and we are going to ride
|
|
* this thread up to userland as an upcall.
|
|
* Do the last parts of the setup needed for the upcall.
|
|
*/
|
|
CTR3(KTR_PROC, "userret: upcall thread %p (pid %d, %s)",
|
|
td, td->td_proc->p_pid, td->td_proc->p_comm);
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_flags &= ~TDF_UPCALLING;
|
|
if (ku->ku_flags & KUF_DOUPCALL)
|
|
ku->ku_flags &= ~KUF_DOUPCALL;
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
/*
|
|
* Set user context to the UTS
|
|
*/
|
|
if (!(ku->ku_mflags & KMF_NOUPCALL)) {
|
|
cpu_set_upcall_kse(td, ku);
|
|
error = suword(&ku->ku_mailbox->km_curthread, 0);
|
|
if (error)
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Unhook the list of completed threads.
|
|
* anything that completes after this gets to
|
|
* come in next time.
|
|
* Put the list of completed thread mailboxes on
|
|
* this KSE's mailbox.
|
|
*/
|
|
if (!(ku->ku_mflags & KMF_NOCOMPLETED) &&
|
|
(error = thread_link_mboxes(kg, ku)) != 0)
|
|
goto out;
|
|
}
|
|
if (!uts_crit) {
|
|
nanotime(&ts);
|
|
error = copyout(&ts, &ku->ku_mailbox->km_timeofday, sizeof(ts));
|
|
}
|
|
|
|
out:
|
|
if (error) {
|
|
/*
|
|
* Things are going to be so screwed we should just kill
|
|
* the process.
|
|
* how do we do that?
|
|
*/
|
|
PROC_LOCK(td->td_proc);
|
|
psignal(td->td_proc, SIGSEGV);
|
|
PROC_UNLOCK(td->td_proc);
|
|
} else {
|
|
/*
|
|
* Optimisation:
|
|
* Ensure that we have a spare thread available,
|
|
* for when we re-enter the kernel.
|
|
*/
|
|
if (td->td_standin == NULL)
|
|
thread_alloc_spare(td, NULL);
|
|
}
|
|
|
|
ku->ku_mflags = 0;
|
|
/*
|
|
* Clear thread mailbox first, then clear system tick count.
|
|
* The order is important because thread_statclock() use
|
|
* mailbox pointer to see if it is an userland thread or
|
|
* an UTS kernel thread.
|
|
*/
|
|
td->td_mailbox = NULL;
|
|
td->td_usticks = 0;
|
|
return (error); /* go sync */
|
|
}
|
|
|
|
/*
|
|
* Enforce single-threading.
|
|
*
|
|
* Returns 1 if the caller must abort (another thread is waiting to
|
|
* exit the process or similar). Process is locked!
|
|
* Returns 0 when you are successfully the only thread running.
|
|
* A process has successfully single threaded in the suspend mode when
|
|
* There are no threads in user mode. Threads in the kernel must be
|
|
* allowed to continue until they get to the user boundary. They may even
|
|
* copy out their return values and data before suspending. They may however be
|
|
* accellerated in reaching the user boundary as we will wake up
|
|
* any sleeping threads that are interruptable. (PCATCH).
|
|
*/
|
|
int
|
|
thread_single(int force_exit)
|
|
{
|
|
struct thread *td;
|
|
struct thread *td2;
|
|
struct proc *p;
|
|
|
|
td = curthread;
|
|
p = td->td_proc;
|
|
mtx_assert(&Giant, MA_OWNED);
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
KASSERT((td != NULL), ("curthread is NULL"));
|
|
|
|
if ((p->p_flag & P_THREADED) == 0 && p->p_numthreads == 1)
|
|
return (0);
|
|
|
|
/* Is someone already single threading? */
|
|
if (p->p_singlethread)
|
|
return (1);
|
|
|
|
if (force_exit == SINGLE_EXIT) {
|
|
p->p_flag |= P_SINGLE_EXIT;
|
|
} else
|
|
p->p_flag &= ~P_SINGLE_EXIT;
|
|
p->p_flag |= P_STOPPED_SINGLE;
|
|
mtx_lock_spin(&sched_lock);
|
|
p->p_singlethread = td;
|
|
while ((p->p_numthreads - p->p_suspcount) != 1) {
|
|
FOREACH_THREAD_IN_PROC(p, td2) {
|
|
if (td2 == td)
|
|
continue;
|
|
td2->td_flags |= TDF_ASTPENDING;
|
|
if (TD_IS_INHIBITED(td2)) {
|
|
if (force_exit == SINGLE_EXIT) {
|
|
if (TD_IS_SUSPENDED(td2)) {
|
|
thread_unsuspend_one(td2);
|
|
}
|
|
if (TD_ON_SLEEPQ(td2) &&
|
|
(td2->td_flags & TDF_SINTR)) {
|
|
if (td2->td_flags & TDF_CVWAITQ)
|
|
cv_abort(td2);
|
|
else
|
|
abortsleep(td2);
|
|
}
|
|
} else {
|
|
if (TD_IS_SUSPENDED(td2))
|
|
continue;
|
|
/*
|
|
* maybe other inhibitted states too?
|
|
* XXXKSE Is it totally safe to
|
|
* suspend a non-interruptable thread?
|
|
*/
|
|
if (td2->td_inhibitors &
|
|
(TDI_SLEEPING | TDI_SWAPPED))
|
|
thread_suspend_one(td2);
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* Maybe we suspended some threads.. was it enough?
|
|
*/
|
|
if ((p->p_numthreads - p->p_suspcount) == 1)
|
|
break;
|
|
|
|
/*
|
|
* Wake us up when everyone else has suspended.
|
|
* In the mean time we suspend as well.
|
|
*/
|
|
thread_suspend_one(td);
|
|
DROP_GIANT();
|
|
PROC_UNLOCK(p);
|
|
p->p_stats->p_ru.ru_nvcsw++;
|
|
mi_switch();
|
|
mtx_unlock_spin(&sched_lock);
|
|
PICKUP_GIANT();
|
|
PROC_LOCK(p);
|
|
mtx_lock_spin(&sched_lock);
|
|
}
|
|
if (force_exit == SINGLE_EXIT) {
|
|
if (td->td_upcall)
|
|
upcall_remove(td);
|
|
kse_purge(p, td);
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Called in from locations that can safely check to see
|
|
* whether we have to suspend or at least throttle for a
|
|
* single-thread event (e.g. fork).
|
|
*
|
|
* Such locations include userret().
|
|
* If the "return_instead" argument is non zero, the thread must be able to
|
|
* accept 0 (caller may continue), or 1 (caller must abort) as a result.
|
|
*
|
|
* The 'return_instead' argument tells the function if it may do a
|
|
* thread_exit() or suspend, or whether the caller must abort and back
|
|
* out instead.
|
|
*
|
|
* If the thread that set the single_threading request has set the
|
|
* P_SINGLE_EXIT bit in the process flags then this call will never return
|
|
* if 'return_instead' is false, but will exit.
|
|
*
|
|
* P_SINGLE_EXIT | return_instead == 0| return_instead != 0
|
|
*---------------+--------------------+---------------------
|
|
* 0 | returns 0 | returns 0 or 1
|
|
* | when ST ends | immediatly
|
|
*---------------+--------------------+---------------------
|
|
* 1 | thread exits | returns 1
|
|
* | | immediatly
|
|
* 0 = thread_exit() or suspension ok,
|
|
* other = return error instead of stopping the thread.
|
|
*
|
|
* While a full suspension is under effect, even a single threading
|
|
* thread would be suspended if it made this call (but it shouldn't).
|
|
* This call should only be made from places where
|
|
* thread_exit() would be safe as that may be the outcome unless
|
|
* return_instead is set.
|
|
*/
|
|
int
|
|
thread_suspend_check(int return_instead)
|
|
{
|
|
struct thread *td;
|
|
struct proc *p;
|
|
struct ksegrp *kg;
|
|
|
|
td = curthread;
|
|
p = td->td_proc;
|
|
kg = td->td_ksegrp;
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
while (P_SHOULDSTOP(p)) {
|
|
if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
|
|
KASSERT(p->p_singlethread != NULL,
|
|
("singlethread not set"));
|
|
/*
|
|
* The only suspension in action is a
|
|
* single-threading. Single threader need not stop.
|
|
* XXX Should be safe to access unlocked
|
|
* as it can only be set to be true by us.
|
|
*/
|
|
if (p->p_singlethread == td)
|
|
return (0); /* Exempt from stopping. */
|
|
}
|
|
if (return_instead)
|
|
return (1);
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
thread_stopped(p);
|
|
/*
|
|
* If the process is waiting for us to exit,
|
|
* this thread should just suicide.
|
|
* Assumes that P_SINGLE_EXIT implies P_STOPPED_SINGLE.
|
|
*/
|
|
if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) {
|
|
while (mtx_owned(&Giant))
|
|
mtx_unlock(&Giant);
|
|
if (p->p_flag & P_THREADED)
|
|
thread_exit();
|
|
else
|
|
thr_exit1();
|
|
}
|
|
|
|
/*
|
|
* When a thread suspends, it just
|
|
* moves to the processes's suspend queue
|
|
* and stays there.
|
|
*/
|
|
thread_suspend_one(td);
|
|
if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
|
|
if (p->p_numthreads == p->p_suspcount) {
|
|
thread_unsuspend_one(p->p_singlethread);
|
|
}
|
|
}
|
|
DROP_GIANT();
|
|
PROC_UNLOCK(p);
|
|
p->p_stats->p_ru.ru_nivcsw++;
|
|
mi_switch();
|
|
mtx_unlock_spin(&sched_lock);
|
|
PICKUP_GIANT();
|
|
PROC_LOCK(p);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
thread_suspend_one(struct thread *td)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
KASSERT(!TD_IS_SUSPENDED(td), ("already suspended"));
|
|
p->p_suspcount++;
|
|
TD_SET_SUSPENDED(td);
|
|
TAILQ_INSERT_TAIL(&p->p_suspended, td, td_runq);
|
|
/*
|
|
* Hack: If we are suspending but are on the sleep queue
|
|
* then we are in msleep or the cv equivalent. We
|
|
* want to look like we have two Inhibitors.
|
|
* May already be set.. doesn't matter.
|
|
*/
|
|
if (TD_ON_SLEEPQ(td))
|
|
TD_SET_SLEEPING(td);
|
|
}
|
|
|
|
void
|
|
thread_unsuspend_one(struct thread *td)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
TAILQ_REMOVE(&p->p_suspended, td, td_runq);
|
|
TD_CLR_SUSPENDED(td);
|
|
p->p_suspcount--;
|
|
setrunnable(td);
|
|
}
|
|
|
|
/*
|
|
* Allow all threads blocked by single threading to continue running.
|
|
*/
|
|
void
|
|
thread_unsuspend(struct proc *p)
|
|
{
|
|
struct thread *td;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
if (!P_SHOULDSTOP(p)) {
|
|
while (( td = TAILQ_FIRST(&p->p_suspended))) {
|
|
thread_unsuspend_one(td);
|
|
}
|
|
} else if ((P_SHOULDSTOP(p) == P_STOPPED_SINGLE) &&
|
|
(p->p_numthreads == p->p_suspcount)) {
|
|
/*
|
|
* Stopping everything also did the job for the single
|
|
* threading request. Now we've downgraded to single-threaded,
|
|
* let it continue.
|
|
*/
|
|
thread_unsuspend_one(p->p_singlethread);
|
|
}
|
|
}
|
|
|
|
void
|
|
thread_single_end(void)
|
|
{
|
|
struct thread *td;
|
|
struct proc *p;
|
|
|
|
td = curthread;
|
|
p = td->td_proc;
|
|
PROC_LOCK_ASSERT(p, MA_OWNED);
|
|
p->p_flag &= ~P_STOPPED_SINGLE;
|
|
mtx_lock_spin(&sched_lock);
|
|
p->p_singlethread = NULL;
|
|
/*
|
|
* If there are other threads they mey now run,
|
|
* unless of course there is a blanket 'stop order'
|
|
* on the process. The single threader must be allowed
|
|
* to continue however as this is a bad place to stop.
|
|
*/
|
|
if ((p->p_numthreads != 1) && (!P_SHOULDSTOP(p))) {
|
|
while (( td = TAILQ_FIRST(&p->p_suspended))) {
|
|
thread_unsuspend_one(td);
|
|
}
|
|
}
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
|
|
|