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freebsd-nq/sys/kern/subr_trap.c

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Initial import, 0.1 + pk 0.2.4-B1
1993-06-12 14:58:17 +00:00
/*-
trap.c: Vastly improved trap.c from me. This rewritten version has a variety of features, amoung them: higher performance and much higher code quality. support.s, cpufunc.h: No longer use gs override to enforce range limits - compare directly against VM_MAXUSER_ADDRESS instead. The old way caused problems in preserving the gs selector...and this method is just as fast or faster.
1994-06-06 14:54:41 +00:00
* Copyright (C) 1994, David Greenman
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
Kernel and hwpmc(4) support for callchain capture. Sponsored by: FreeBSD Foundation and Google Inc.
2007-12-07 08:20:17 +00:00
* Copyright (c) 2007 The FreeBSD Foundation
Initial import, 0.1 + pk 0.2.4-B1
1993-06-12 14:58:17 +00:00
*
* This code is derived from software contributed to Berkeley by
* the University of Utah, and William Jolitz.
*
Kernel and hwpmc(4) support for callchain capture. Sponsored by: FreeBSD Foundation and Google Inc.
2007-12-07 08:20:17 +00:00
* Portions of this software were developed by A. Joseph Koshy under
* sponsorship from the FreeBSD Foundation and Google, Inc.
*
Initial import, 0.1 + pk 0.2.4-B1
1993-06-12 14:58:17 +00:00
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
genassym.c: Remove NKMEMCLUSTERS, it is no longer define or used. locores.s: Fix comment on PTDpde and APTDpde to be pde instead of pte Add new equation for calculating location of Sysmap Remove Bill's old #ifdef garbage for counting up memory, that stuff will never be made to work and was just cluttering up the file. Add code that places the PTD, page table pages, and kernel stack below the 640k ISA hole if there is room for it, otherwise put this stuff all at 1MB. This fixes the 28K bogusity in the boot blocks, that can now go away! Fix the caclulation of where first is to be dependent on NKPDE so that we can skip over the above mentioned areas. The 28K thing is now 44K in size due to the increase in kernel virtual memory space, but since we no longer have to worry about that this is no big deal. Use if NNPX > 0 instead of ifdef NPX for floating point code. machdep.c Change the calculation of for the buffer cache to be 20% of all memory above 2MB and add back the upper limit of 2/5's of the VM_KMEM_SIZE so that we do not eat ALL of the kernel memory space on large memory machines, note that this will not even come into effect unless you have more than 32MB. The current buffer cache limit is 6.7MB due to this caclulation. It seems that we where erroniously allocating bufpages pages for buffer_map. buffer_map is UNUSED in this implementation of the buffer cache, but since the map is referenced in several if statements a quick fix was to simply allocate 1 vm page (but no real memory) to it. pmap.h Remove rcsid, don't want them in the kernel files! Removed some cruft inside an #ifdef DEBUGx that caused compiler errors if you where compiling this for debug. Use the #defines for PD_SHIFT and PG_SHIFT in place of constants. trap.c: Remove patch kit header and rcsid, fix $Id$. Now include "npx.h" and use NNPX for controlling the floating point code. Remove a now completly invalid check for a maximum virtual address, the virtual address now ends at 0xFFFFFFFF so there is no more MAX!! (Thanks David, I completly missed that one!) vm_machdep.c Remove patch kit header and rcsid, fix $Id$. Now include "npx.h" and use NNPX for controlling the floating point code. Replace several 0xFE00000 constants with KERNBASE
1993-10-15 10:34:29 +00:00
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
Initial import, 0.1 + pk 0.2.4-B1
1993-06-12 14:58:17 +00:00
*/
Use __FBSDID().
2003-06-11 00:56:59 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
Kernel and hwpmc(4) support for callchain capture. Sponsored by: FreeBSD Foundation and Google Inc.
2007-12-07 08:20:17 +00:00
#include "opt_hwpmc_hooks.h"
When ktracing context switches, make sure we record involuntary switches. Otherwise, when we get a evicted from the cpu, there is no record of it. This is not a default ktrace flag.
2003-07-31 01:36:24 +00:00
#include "opt_ktrace.h"
Add a new MAC entry point, mac_thread_userret(td), which permits policy modules to perform MAC-related events when a thread returns to user space. This is required for policies that have floating process labels, as it's not always possible to acquire the process lock at arbitrary points in the stack during system call processing; process labels might represent traditional authentication data, process history information, or other data. LOMAC will use this entry point to perform the process label update prior to the thread returning to userspace, when plugged into the MAC framework. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-02 02:42:38 +00:00
#include "opt_mac.h"
Move ast() and userret() to sys/kern/subr_trap.c now that they are MI.
2001-06-29 19:51:37 +00:00
#ifdef __i386__
Use #ifdef DEV_NPX from opt_npx.h instead of #if NNPX > 0 from npx.h
2001-01-19 13:19:02 +00:00
#include "opt_npx.h"
Move ast() and userret() to sys/kern/subr_trap.c now that they are MI.
2001-06-29 19:51:37 +00:00
#endif
- Include opt_sched.h for SCHED_STATS.
2007-06-12 23:27:31 +00:00
#include "opt_sched.h"
Converted two options over to the new scheme: USER_LDT and KTRACE.
1996-01-03 21:42:35 +00:00
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
#include <sys/param.h>
Major update to the way synchronization is done in the kernel. Highlights include: * Mutual exclusion is used instead of spl*(). See mutex(9). (Note: The alpha port is still in transition and currently uses both.) * Per-CPU idle processes. * Interrupts are run in their own separate kernel threads and can be preempted (i386 only). Partially contributed by: BSDi (BSD/OS) Submissions by (at least): cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
#include <sys/bus.h>
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
#include <sys/kernel.h>
Move ast() and userret() to sys/kern/subr_trap.c now that they are MI.
2001-06-29 19:51:37 +00:00
#include <sys/lock.h>
Catch up to moving headers: - machine/ipl.h -> sys/ipl.h - machine/mutex.h -> sys/mutex.h
2000-10-20 07:58:15 +00:00
#include <sys/mutex.h>
Kernel and hwpmc(4) support for callchain capture. Sponsored by: FreeBSD Foundation and Google Inc.
2007-12-07 08:20:17 +00:00
#include <sys/pmckern.h>
Move ast() and userret() to sys/kern/subr_trap.c now that they are MI.
2001-06-29 19:51:37 +00:00
#include <sys/proc.h>
Part 1 of KSE-III The ability to schedule multiple threads per process (one one cpu) by making ALL system calls optionally asynchronous. to come: ia64 and power-pc patches, patches for gdb, test program (in tools) Reviewed by: Almost everyone who counts (at various times, peter, jhb, matt, alfred, mini, bernd, and a cast of thousands) NOTE: this is still Beta code, and contains lots of debugging stuff. expect slight instability in signals..
2002-06-29 17:26:22 +00:00
#include <sys/ktr.h>
Fixed some #include messes. Hid the check of the user %cs in syscall() under `#ifdef DIAGNOSTIC'.
1997-11-24 13:25:37 +00:00
#include <sys/resourcevar.h>
- Create a new scheduler api that is defined in sys/sched.h - Begin moving scheduler specific functionality into sched_4bsd.c - Replace direct manipulation of scheduler data with hooks provided by the new api. - Remove KSE specific state modifications and single runq assumptions from kern_switch.c Reviewed by: -arch
2002-10-12 05:32:24 +00:00
#include <sys/sched.h>
Fixed some #include messes. Hid the check of the user %cs in syscall() under `#ifdef DIAGNOSTIC'.
1997-11-24 13:25:37 +00:00
#include <sys/signalvar.h>
Move ast() and userret() to sys/kern/subr_trap.c now that they are MI.
2001-06-29 19:51:37 +00:00
#include <sys/systm.h>
Untangled the vm.h include file spaghetti.
1995-12-07 12:48:31 +00:00
#include <sys/vmmeter.h>
When ktracing context switches, make sure we record involuntary switches. Otherwise, when we get a evicted from the cpu, there is no record of it. This is not a default ktrace flag.
2003-07-31 01:36:24 +00:00
#ifdef KTRACE
#include <sys/uio.h>
#include <sys/ktrace.h>
#endif
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
#include <machine/cpu.h>
Fixed some #include messes. Hid the check of the user %cs in syscall() under `#ifdef DIAGNOSTIC'.
1997-11-24 13:25:37 +00:00
#include <machine/pcb.h>
- Add code to detect if a system call returns with locks other than Giant held and panic if so (conditional on witness). - Change witness_list to return the number of locks held so this is easier. - Add kern/syscalls.c to the kernel build if witness is defined so that the panic message can contain the name of the offending system call. - Add assertions that Giant and sched_lock are not held when returning from a system call, which were missing for alpha and ia64.
2000-12-12 01:14:32 +00:00
Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now contains the userspace and user<->kernel API and definitions, with all in-kernel interfaces moved to mac_framework.h, which is now included across most of the kernel instead. This change is the first step in a larger cleanup and sweep of MAC Framework interfaces in the kernel, and will not be MFC'd. Obtained from: TrustedBSD Project Sponsored by: SPARTA
2006-10-22 11:52:19 +00:00
#include <security/mac/mac_framework.h>
Move ast() and userret() to sys/kern/subr_trap.c now that they are MI.
2001-06-29 19:51:37 +00:00
/*
Remove 'MPSAFE' annotations from the comments above most system calls: all system calls now enter without Giant held, and then in some cases, acquire Giant explicitly. Remove a number of other MPSAFE annotations in the credential code and tweak one or two other adjacent comments.
2007-03-04 22:36:48 +00:00
* Define the code needed before returning to user mode, for trap and
* syscall.
Move ast() and userret() to sys/kern/subr_trap.c now that they are MI.
2001-06-29 19:51:37 +00:00
*/
- Kill the have_giant parameter to userret() along with all instances of that name as a variable. Use mtx_owned(&Giant) where appropriate instead. - Proc locking. - P_FOO -> PS_FOO. - Update comments about enable interrupts during trap and why this may be bad if we trap while holding a spin mutex. - Don't bother resetting p to curproc in syscall() in case we are the child returning from fork. The child hasn't returned from fork through syscall in a while. - Remove fork_return() as it has been superseded by the MI version.
2001-01-24 09:53:49 +00:00
void
Simplify system time accounting for profiling. Rename struct thread's td_sticks to td_pticks, we will need the other name for more appropriately named use shortly. Reduce it from uint64_t to u_int. Clear td_pticks whenever we enter the kernel instead of recording its value as reference for userret(). Use the absolute value of td->pticks in userret() and eliminate third argument.
2006-02-08 08:09:17 +00:00
userret(struct thread *td, struct trapframe *frame)
trap.c: Vastly improved trap.c from me. This rewritten version has a variety of features, amoung them: higher performance and much higher code quality. support.s, cpufunc.h: No longer use gs override to enforce range limits - compare directly against VM_MAXUSER_ADDRESS instead. The old way caused problems in preserving the gs selector...and this method is just as fast or faster.
1994-06-06 14:54:41 +00:00
{
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
struct proc *p = td->td_proc;
trap.c: Vastly improved trap.c from me. This rewritten version has a variety of features, amoung them: higher performance and much higher code quality. support.s, cpufunc.h: No longer use gs override to enforce range limits - compare directly against VM_MAXUSER_ADDRESS instead. The old way caused problems in preserving the gs selector...and this method is just as fast or faster.
1994-06-06 14:54:41 +00:00
Part 1 of KSE-III The ability to schedule multiple threads per process (one one cpu) by making ALL system calls optionally asynchronous. to come: ia64 and power-pc patches, patches for gdb, test program (in tools) Reviewed by: Almost everyone who counts (at various times, peter, jhb, matt, alfred, mini, bernd, and a cast of thousands) NOTE: this is still Beta code, and contains lots of debugging stuff. expect slight instability in signals..
2002-06-29 17:26:22 +00:00
CTR3(KTR_SYSC, "userret: thread %p (pid %d, %s)", td, p->p_pid,
A bunch more files that should probably print out a thread name instead of a process name.
2007-11-14 06:51:33 +00:00
td->td_name);
Put "failed to set signal flags properly for ast()" check under DIAGNOSTIC instead of INVARIANTS. INVARIANTS is intended for tests that don't substantially change code flow or behavior (passive), but this test required locking both the proc lock and scheduler lock in order to execute. It also appears to be a very advisory diagnostic as opposed to an invariant violation. Following discussion with: bde
2004-03-05 17:35:28 +00:00
#ifdef DIAGNOSTIC
Reversion of commit by Davidxu plus fixes since applied. I'm not convinced there is anything major wrong with the patch but them's the rules.. I am using my "David's mentor" hat to revert this as he's offline for a while.
2003-02-01 12:17:09 +00:00
/* Check that we called signotify() enough. */
- Grab the proc lock around CURSIG and postsig(). Don't release the proc lock until after grabbing the sched_lock to avoid CURSIG racing with psignal. - Don't grab Giant for addupc_task() as it isn't needed. Reported by: tegge (signal race), bde (addupc_task a while back)
2001-06-22 23:05:11 +00:00
PROC_LOCK(p);
Commit 14/14 of sched_lock decomposition. - Use thread_lock() rather than sched_lock for per-thread scheduling sychronization. - Use the per-process spinlock rather than the sched_lock for per-process scheduling synchronization. Tested by: kris, current@ Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc. Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
thread_lock(td);
- Move p->p_sigmask to td->td_sigmask. Signal masks will be per thread with a follow on commit to kern_sig.c - signotify() now operates on a thread since unmasked pending signals are stored in the thread. - PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.
2003-03-31 22:49:17 +00:00
if (SIGPENDING(td) && ((td->td_flags & TDF_NEEDSIGCHK) == 0 ||
Move a bunch of flags from the KSE to the thread. I was in two minds as to where to put them in the first case.. I should have listenned to the other mind. Submitted by: parts by davidxu@ Reviewed by: jeff@ mini@
2003-02-17 09:55:10 +00:00
(td->td_flags & TDF_ASTPENDING) == 0))
Spell proprly properly: failed to set signal flags proprly for ast() failed to set signal flags proprly for ast() failed to set signal flags proprly for ast() failed to set signal flags proprly for ast()
2002-08-22 14:36:03 +00:00
printf("failed to set signal flags properly for ast()\n");
Commit 14/14 of sched_lock decomposition. - Use thread_lock() rather than sched_lock for per-thread scheduling sychronization. - Use the per-process spinlock rather than the sched_lock for per-process scheduling synchronization. Tested by: kris, current@ Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc. Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
thread_unlock(td);
- Close races with signals and other AST's being triggered while we are in the process of exiting the kernel. The ast() function now loops as long as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with preemption disabled so that any further AST's that arrive via an interrupt will be delayed until the low-level MD code returns to user mode. - Use u_int's to store the tick counts for profiling purposes so that we do not need sched_lock just to read p_sticks. This also closes a problem where the call to addupc_task() could screw up the arithmetic due to non-atomic reads of p_sticks. - Axe need_proftick(), aston(), astoff(), astpending(), need_resched(), clear_resched(), and resched_wanted() in favor of direct bit operations on p_sflag. - Fix up locking with sched_lock some. In addupc_intr(), use sched_lock to ensure pr_addr and pr_ticks are updated atomically with setting PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing PS_OWEUPC. We also do not grab the lock just to test a flag. - Simplify the handling of Giant in ast() slightly. Reviewed by: bde (mostly)
2001-08-10 22:53:32 +00:00
PROC_UNLOCK(p);
Moved signal handling and rescheduling from userret() to ast() so that they aren't in the usual path of execution for syscalls and traps. The main complication for this is that we have to set flags to control ast() everywhere that changes the signal mask. Avoid locking in userret() in most of the remaining cases. Submitted by: luoqi (first part only, long ago, reorganized by me) Reminded by: dillon
2002-04-04 17:49:48 +00:00
#endif
Moderate rewrite of kernel ktrace code to attempt to generally improve reliability when tracing fast-moving processes or writing traces to slow file systems by avoiding unbounded queueuing and dropped records. Record loss was previously possible when the global pool of records become depleted as a result of record generation outstripping record commit, which occurred quickly in many common situations. These changes partially restore the 4.x model of committing ktrace records at the point of trace generation (synchronous), but maintain the 5.x deferred record commit behavior (asynchronous) for situations where entering VFS and sleeping is not possible (i.e., in the scheduler). Records are now queued per-process as opposed to globally, with processes responsible for committing records from their own context as required. - Eliminate the ktrace worker thread and global record queue, as they are no longer used. Keep the global free record list, as records are still used. - Add a per-process record queue, which will hold any asynchronously generated records, such as from context switches. This replaces the global queue as the place to submit asynchronous records to. - When a record is committed asynchronously, simply queue it to the process. - When a record is committed synchronously, first drain any pending per-process records in order to maintain ordering as best we can. Currently ordering between competing threads is provided via a global ktrace_sx, but a per-process flag or lock may be desirable in the future. - When a process returns to user space following a system call, trap, signal delivery, etc, flush any pending records. - When a process exits, flush any pending records. - Assert on process tear-down that there are no pending records. - Slightly abstract the notion of being "in ktrace", which is used to prevent the recursive generation of records, as well as generating traces for ktrace events. Future work here might look at changing the set of events marked for synchronous and asynchronous record generation, re-balancing queue depth, timeliness of commit to disk, and so on. I.e., performing a drain every (n) records. MFC after: 1 month Discussed with: jhb Requested by: Marc Olzheim <marcolz at stack dot nl>
2005-11-13 13:27:44 +00:00
#ifdef KTRACE
KTRUSERRET(td);
#endif
Add a new per-thread private flag: TDP_GEOM. This flag gets set whenever the thread posts an event on the GEOM event queue, and if the flag is set when the thread is prepared to return to userland from the kernel, g_waitidle() will be called to make sure that the posted events have completed. This can replace an insufficient number of g_waitidle() calls in various other places, and has the advantage of being failsafe: Any system call which does a VOP_OPEN()/VOP_CLOSE will now correctly wait for any geom events it posted as part of spoils or tastes. Assert that topology and Giant is not held in g_waitidle().
2004-10-23 20:49:17 +00:00
/*
* If this thread tickled GEOM, we need to wait for the giggling to
* stop before we return to userland
*/
if (td->td_pflags & TDP_GEOM)
g_waitidle();
Reversion of commit by Davidxu plus fixes since applied. I'm not convinced there is anything major wrong with the patch but them's the rules.. I am using my "David's mentor" hat to revert this as he's offline for a while.
2003-02-01 12:17:09 +00:00
/*
* Charge system time if profiling.
*/
- Move PS_PROFIL and its new cousin PS_STOPPROF back over to p_flag and rename them appropriately. Protect both flags with both the proc lock and the sched_lock. - Protect p_profthreads with the proc lock. - Remove Giant from profil(2).
2003-04-22 20:54:04 +00:00
if (p->p_flag & P_PROFIL) {
Simplify system time accounting for profiling. Rename struct thread's td_sticks to td_pticks, we will need the other name for more appropriately named use shortly. Reduce it from uint64_t to u_int. Clear td_pticks whenever we enter the kernel instead of recording its value as reference for userret(). Use the absolute value of td->pticks in userret() and eliminate third argument.
2006-02-08 08:09:17 +00:00
addupc_task(td, TRAPF_PC(frame), td->td_pticks * psratio);
Reversion of commit by Davidxu plus fixes since applied. I'm not convinced there is anything major wrong with the patch but them's the rules.. I am using my "David's mentor" hat to revert this as he's offline for a while.
2003-02-01 12:17:09 +00:00
}
- Run sched_userret() after thread_userret(). Before, sched_userret() would lower the priority of the returning thread to a user priority before calling into thread_userret() which would call wakeup() which in turn would cause the returning thread to eventually context switch rather than completing its slice. Allowing this thread to complete its slice first yields a 15% performance improvement in super-smack on my dual opteron with 4BSD.
2004-12-26 07:30:35 +00:00
/*
* Let the scheduler adjust our priority etc.
*/
sched_userret(td);
- Fail an assert if we attempt to return with any lockmgr locks held in userret(). Sponsored by: Isilon Systems, Inc.
2005-03-24 09:35:38 +00:00
KASSERT(td->td_locks == 0,
("userret: Returning with %d locks held.", td->td_locks));
trap.c: Vastly improved trap.c from me. This rewritten version has a variety of features, amoung them: higher performance and much higher code quality. support.s, cpufunc.h: No longer use gs override to enforce range limits - compare directly against VM_MAXUSER_ADDRESS instead. The old way caused problems in preserving the gs selector...and this method is just as fast or faster.
1994-06-06 14:54:41 +00:00
}
Initial import, 0.1 + pk 0.2.4-B1
1993-06-12 14:58:17 +00:00
/*
Move ast() and userret() to sys/kern/subr_trap.c now that they are MI.
2001-06-29 19:51:37 +00:00
* Process an asynchronous software trap.
* This is relatively easy.
- Close races with signals and other AST's being triggered while we are in the process of exiting the kernel. The ast() function now loops as long as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with preemption disabled so that any further AST's that arrive via an interrupt will be delayed until the low-level MD code returns to user mode. - Use u_int's to store the tick counts for profiling purposes so that we do not need sched_lock just to read p_sticks. This also closes a problem where the call to addupc_task() could screw up the arithmetic due to non-atomic reads of p_sticks. - Axe need_proftick(), aston(), astoff(), astpending(), need_resched(), clear_resched(), and resched_wanted() in favor of direct bit operations on p_sflag. - Fix up locking with sched_lock some. In addupc_intr(), use sched_lock to ensure pr_addr and pr_ticks are updated atomically with setting PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing PS_OWEUPC. We also do not grab the lock just to test a flag. - Simplify the handling of Giant in ast() slightly. Reviewed by: bde (mostly)
2001-08-10 22:53:32 +00:00
* This function will return with preemption disabled.
Initial import, 0.1 + pk 0.2.4-B1
1993-06-12 14:58:17 +00:00
*/
Major update to the way synchronization is done in the kernel. Highlights include: * Mutual exclusion is used instead of spl*(). See mutex(9). (Note: The alpha port is still in transition and currently uses both.) * Per-CPU idle processes. * Interrupts are run in their own separate kernel threads and can be preempted (i386 only). Partially contributed by: BSDi (BSD/OS) Submissions by (at least): cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
void
Part 1 of KSE-III The ability to schedule multiple threads per process (one one cpu) by making ALL system calls optionally asynchronous. to come: ia64 and power-pc patches, patches for gdb, test program (in tools) Reviewed by: Almost everyone who counts (at various times, peter, jhb, matt, alfred, mini, bernd, and a cast of thousands) NOTE: this is still Beta code, and contains lots of debugging stuff. expect slight instability in signals..
2002-06-29 17:26:22 +00:00
ast(struct trapframe *framep)
Major update to the way synchronization is done in the kernel. Highlights include: * Mutual exclusion is used instead of spl*(). See mutex(9). (Note: The alpha port is still in transition and currently uses both.) * Per-CPU idle processes. * Interrupts are run in their own separate kernel threads and can be preempted (i386 only). Partially contributed by: BSDi (BSD/OS) Submissions by (at least): cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
{
Various style fixups. Submitted by: bde (mostly)
2002-10-01 14:16:50 +00:00
struct thread *td;
struct proc *p;
KSE Milestone 2 Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
2001-09-12 08:38:13 +00:00
int flags;
Moved signal handling and rescheduling from userret() to ast() so that they aren't in the usual path of execution for syscalls and traps. The main complication for this is that we have to set flags to control ast() everywhere that changes the signal mask. Avoid locking in userret() in most of the remaining cases. Submitted by: luoqi (first part only, long ago, reorganized by me) Reminded by: dillon
2002-04-04 17:49:48 +00:00
int sig;
Convert npx interrupts into traps instead of vice versa. This is much simpler for npx exceptions that start as traps (no assembly required...) and works better for npx exceptions that start as interrupts (there is no longer a problem for nested interrupts). Submitted by: original (pre-SMPng) version by luoqi
2001-05-22 21:20:49 +00:00
#if defined(DEV_NPX) && !defined(SMP)
int ucode;
1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most changes in MD code are trivial, before this change, trapsignal and sendsig use discrete parameters, now they uses member fields of ksiginfo_t structure. For sendsig, this change allows us to pass POSIX realtime signal value to user code. 2. Remove cpu_thread_siginfo, it is no longer needed because we now always generate ksiginfo_t data and feed it to libpthread. 3. Add p_sigqueue to proc structure to hold shared signals which were blocked by all threads in the proc. 4. Add td_sigqueue to thread structure to hold all signals delivered to thread. 5. i386 and amd64 now return POSIX standard si_code, other arches will be fixed. 6. In this sigqueue implementation, pending signal set is kept as before, an extra siginfo list holds additional siginfo_t data for signals. kernel code uses psignal() still behavior as before, it won't be failed even under memory pressure, only exception is when deleting a signal, we should call sigqueue_delete to remove signal from sigqueue but not SIGDELSET. Current there is no kernel code will deliver a signal with additional data, so kernel should be as stable as before, a ksiginfo can carry more information, for example, allow signal to be delivered but throw away siginfo data if memory is not enough. SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can not be caught or masked. The sigqueue() syscall allows user code to queue a signal to target process, if resource is unavailable, EAGAIN will be returned as specification said. Just before thread exits, signal queue memory will be freed by sigqueue_flush. Current, all signals are allowed to be queued, not only realtime signals. Earlier patch reviewed by: jhb, deischen Tested on: i386, amd64
2005-10-14 12:43:47 +00:00
ksiginfo_t ksi;
Convert npx interrupts into traps instead of vice versa. This is much simpler for npx exceptions that start as traps (no assembly required...) and works better for npx exceptions that start as interrupts (there is no longer a problem for nested interrupts). Submitted by: original (pre-SMPng) version by luoqi
2001-05-22 21:20:49 +00:00
#endif
Major update to the way synchronization is done in the kernel. Highlights include: * Mutual exclusion is used instead of spl*(). See mutex(9). (Note: The alpha port is still in transition and currently uses both.) * Per-CPU idle processes. * Interrupts are run in their own separate kernel threads and can be preempted (i386 only). Partially contributed by: BSDi (BSD/OS) Submissions by (at least): cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
Various style fixups. Submitted by: bde (mostly)
2002-10-01 14:16:50 +00:00
td = curthread;
p = td->td_proc;
De-obfuscate local use of members of 'struct thread', for which we have local variables, and group assignment.
2002-10-02 16:39:39 +00:00
Part 1 of KSE-III The ability to schedule multiple threads per process (one one cpu) by making ALL system calls optionally asynchronous. to come: ia64 and power-pc patches, patches for gdb, test program (in tools) Reviewed by: Almost everyone who counts (at various times, peter, jhb, matt, alfred, mini, bernd, and a cast of thousands) NOTE: this is still Beta code, and contains lots of debugging stuff. expect slight instability in signals..
2002-06-29 17:26:22 +00:00
CTR3(KTR_SYSC, "ast: thread %p (pid %d, %s)", td, p->p_pid,
p->p_comm);
- Change ast() to take a pointer to a trapframe like other architectures. - Don't use an atomic operation to update cnt.v_soft in ast(). This is the only place the variable is written to, and sched_lock is always held when it is written, so it is already protected and the mutex release of sched_lock asserts a memory barrier that ensures the value will be updated in a timely fashion.
2001-02-22 18:05:15 +00:00
KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode"));
Replace calls to WITNESS_SLEEP() and witness_list() with equivalent calls to WITNESS_WARN().
2003-03-04 21:03:05 +00:00
WITNESS_WARN(WARN_PANIC, NULL, "Returning to user mode");
- Close races with signals and other AST's being triggered while we are in the process of exiting the kernel. The ast() function now loops as long as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with preemption disabled so that any further AST's that arrive via an interrupt will be delayed until the low-level MD code returns to user mode. - Use u_int's to store the tick counts for profiling purposes so that we do not need sched_lock just to read p_sticks. This also closes a problem where the call to addupc_task() could screw up the arithmetic due to non-atomic reads of p_sticks. - Axe need_proftick(), aston(), astoff(), astpending(), need_resched(), clear_resched(), and resched_wanted() in favor of direct bit operations on p_sflag. - Fix up locking with sched_lock some. In addupc_intr(), use sched_lock to ensure pr_addr and pr_ticks are updated atomically with setting PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing PS_OWEUPC. We also do not grab the lock just to test a flag. - Simplify the handling of Giant in ast() slightly. Reviewed by: bde (mostly)
2001-08-10 22:53:32 +00:00
mtx_assert(&Giant, MA_NOTOWNED);
Commit 14/14 of sched_lock decomposition. - Use thread_lock() rather than sched_lock for per-thread scheduling sychronization. - Use the per-process spinlock rather than the sched_lock for per-process scheduling synchronization. Tested by: kris, current@ Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc. Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
td->td_frame = framep;
Simplify system time accounting for profiling. Rename struct thread's td_sticks to td_pticks, we will need the other name for more appropriately named use shortly. Reduce it from uint64_t to u_int. Clear td_pticks whenever we enter the kernel instead of recording its value as reference for userret(). Use the absolute value of td->pticks in userret() and eliminate third argument.
2006-02-08 08:09:17 +00:00
td->td_pticks = 0;
Various style fixups. Submitted by: bde (mostly)
2002-10-01 14:16:50 +00:00
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
/*
- Move all of the PS_ flags into either p_flag or td_flags. - p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or previously the sched_lock. These bugs have existed for some time. - Allow swapout to try each thread in a process individually and then swapin the whole process if any of these fail. This allows us to move most scheduler related swap flags into td_flags. - Keep ki_sflag for backwards compat but change all in source tools to use the new and more correct location of P_INMEM. Reported by: pho Reviewed by: attilio, kib Approved by: re (kensmith)
2007-09-17 05:31:39 +00:00
* This updates the td_flag's for the checks below in one
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
* "atomic" operation with turning off the astpending flag.
* If another AST is triggered while we are handling the
- Move all of the PS_ flags into either p_flag or td_flags. - p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or previously the sched_lock. These bugs have existed for some time. - Allow swapout to try each thread in a process individually and then swapin the whole process if any of these fail. This allows us to move most scheduler related swap flags into td_flags. - Keep ki_sflag for backwards compat but change all in source tools to use the new and more correct location of P_INMEM. Reported by: pho Reviewed by: attilio, kib Approved by: re (kensmith)
2007-09-17 05:31:39 +00:00
* AST's saved in flags, the astpending flag will be set and
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
* ast() will be called again.
*/
Commit 14/14 of sched_lock decomposition. - Use thread_lock() rather than sched_lock for per-thread scheduling sychronization. - Use the per-process spinlock rather than the sched_lock for per-process scheduling synchronization. Tested by: kris, current@ Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc. Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
thread_lock(td);
flags = td->td_flags;
- Add a new td flag TDF_NEEDSUSPCHK that is set whenever a thread needs to enter thread_suspend_check(). - Set TDF_ASTPENDING along with TDF_NEEDSUSPCHK so we can move the thread_suspend_check() to ast() rather than userret(). - Check TDF_NEEDSUSPCHK in the sleepq_catch_signals() optimization so that we don't miss a suspend request. If this is set use the expensive signal path. - Set NEEDSUSPCHK when creating a new thread in thr in case the creating thread is due to be suspended as well but has not yet. Reviewed by: davidxu (Authored original patch)
2008-03-21 08:23:25 +00:00
td->td_flags &= ~(TDF_ASTPENDING | TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK |
TDF_NEEDRESCHED | TDF_ALRMPEND | TDF_PROFPEND | TDF_MACPEND);
Commit 14/14 of sched_lock decomposition. - Use thread_lock() rather than sched_lock for per-thread scheduling sychronization. - Use the per-process spinlock rather than the sched_lock for per-process scheduling synchronization. Tested by: kris, current@ Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc. Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
thread_unlock(td);
Do proper "locking" for missing vmmeters part. Now, we assume no more sched_lock protection for some of them and use the distribuited loads method for vmmeter (distribuited through CPUs). Reviewed by: alc, bde Approved by: jeff (mentor)
2007-06-04 21:45:18 +00:00
PCPU_INC(cnt.v_trap);
Various small style fixes.
2004-09-22 15:24:33 +00:00
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
if (td->td_ucred != p->p_ucred)
cred_update_thread(td);
- Move TDF_OWEPREEMPT, TDF_OWEUPC, and TDF_USTATCLOCK over to td_pflags since they are only accessed by curthread and thus do not need any locking. - Move pr_addr and pr_ticks out of struct uprof (which is per-process) and directly into struct thread as td_profil_addr and td_profil_ticks as these variables are really per-thread. (They are used to defer an addupc_intr() that was too "hard" until ast()).
2004-07-16 21:04:55 +00:00
if (td->td_pflags & TDP_OWEUPC && p->p_flag & P_PROFIL) {
addupc_task(td, td->td_profil_addr, td->td_profil_ticks);
td->td_profil_ticks = 0;
td->td_pflags &= ~TDP_OWEUPC;
Tidy up uprof locking. Mostly the fields are protected by both the proc lock and sched_lock so they can be read with either lock held. Document the locking as well. The one remaining bogosity is that pr_addr and pr_ticks should be per-thread but profiling of multithreaded apps is currently undefined.
2004-07-02 03:50:48 +00:00
}
Kernel and hwpmc(4) support for callchain capture. Sponsored by: FreeBSD Foundation and Google Inc.
2007-12-07 08:20:17 +00:00
#if defined(HWPMC_HOOKS)
if (td->td_pflags & TDP_CALLCHAIN) {
PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_USER_CALLCHAIN,
(void *) framep);
td->td_pflags &= ~TDP_CALLCHAIN;
}
#endif
- Move all of the PS_ flags into either p_flag or td_flags. - p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or previously the sched_lock. These bugs have existed for some time. - Allow swapout to try each thread in a process individually and then swapin the whole process if any of these fail. This allows us to move most scheduler related swap flags into td_flags. - Keep ki_sflag for backwards compat but change all in source tools to use the new and more correct location of P_INMEM. Reported by: pho Reviewed by: attilio, kib Approved by: re (kensmith)
2007-09-17 05:31:39 +00:00
if (flags & TDF_ALRMPEND) {
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
PROC_LOCK(p);
psignal(p, SIGVTALRM);
PROC_UNLOCK(p);
}
Convert npx interrupts into traps instead of vice versa. This is much simpler for npx exceptions that start as traps (no assembly required...) and works better for npx exceptions that start as interrupts (there is no longer a problem for nested interrupts). Submitted by: original (pre-SMPng) version by luoqi
2001-05-22 21:20:49 +00:00
#if defined(DEV_NPX) && !defined(SMP)
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
if (PCPU_GET(curpcb)->pcb_flags & PCB_NPXTRAP) {
atomic_clear_int(&PCPU_GET(curpcb)->pcb_flags,
PCB_NPXTRAP);
ucode = npxtrap();
if (ucode != -1) {
1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most changes in MD code are trivial, before this change, trapsignal and sendsig use discrete parameters, now they uses member fields of ksiginfo_t structure. For sendsig, this change allows us to pass POSIX realtime signal value to user code. 2. Remove cpu_thread_siginfo, it is no longer needed because we now always generate ksiginfo_t data and feed it to libpthread. 3. Add p_sigqueue to proc structure to hold shared signals which were blocked by all threads in the proc. 4. Add td_sigqueue to thread structure to hold all signals delivered to thread. 5. i386 and amd64 now return POSIX standard si_code, other arches will be fixed. 6. In this sigqueue implementation, pending signal set is kept as before, an extra siginfo list holds additional siginfo_t data for signals. kernel code uses psignal() still behavior as before, it won't be failed even under memory pressure, only exception is when deleting a signal, we should call sigqueue_delete to remove signal from sigqueue but not SIGDELSET. Current there is no kernel code will deliver a signal with additional data, so kernel should be as stable as before, a ksiginfo can carry more information, for example, allow signal to be delivered but throw away siginfo data if memory is not enough. SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can not be caught or masked. The sigqueue() syscall allows user code to queue a signal to target process, if resource is unavailable, EAGAIN will be returned as specification said. Just before thread exits, signal queue memory will be freed by sigqueue_flush. Current, all signals are allowed to be queued, not only realtime signals. Earlier patch reviewed by: jhb, deischen Tested on: i386, amd64
2005-10-14 12:43:47 +00:00
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = SIGFPE;
ksi.ksi_code = ucode;
trapsignal(td, &ksi);
Convert npx interrupts into traps instead of vice versa. This is much simpler for npx exceptions that start as traps (no assembly required...) and works better for npx exceptions that start as interrupts (there is no longer a problem for nested interrupts). Submitted by: original (pre-SMPng) version by luoqi
2001-05-22 21:20:49 +00:00
}
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
}
Convert npx interrupts into traps instead of vice versa. This is much simpler for npx exceptions that start as traps (no assembly required...) and works better for npx exceptions that start as interrupts (there is no longer a problem for nested interrupts). Submitted by: original (pre-SMPng) version by luoqi
2001-05-22 21:20:49 +00:00
#endif
- Move all of the PS_ flags into either p_flag or td_flags. - p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or previously the sched_lock. These bugs have existed for some time. - Allow swapout to try each thread in a process individually and then swapin the whole process if any of these fail. This allows us to move most scheduler related swap flags into td_flags. - Keep ki_sflag for backwards compat but change all in source tools to use the new and more correct location of P_INMEM. Reported by: pho Reviewed by: attilio, kib Approved by: re (kensmith)
2007-09-17 05:31:39 +00:00
if (flags & TDF_PROFPEND) {
Style fixes purposefully left out of last commit. I checked the kse tree and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
PROC_LOCK(p);
psignal(p, SIGPROF);
PROC_UNLOCK(p);
}
To reduce per-return overhead of userret(), call into mac_thread_userret() only if PS_MACPEND is set in the process AST mask. This avoids the cost of the entry point in the common case, but requires policies interested in the userret event to set the flag (protected by the scheduler lock) if they do want the event. Since all the policies that we're working with which use mac_thread_userret() use the entry point only selectively to perform operations deferred for locking reasons, this maintains the desired semantics. Approved by: re Requested by: bde Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-11-08 19:00:17 +00:00
#ifdef MAC
- Move all of the PS_ flags into either p_flag or td_flags. - p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or previously the sched_lock. These bugs have existed for some time. - Allow swapout to try each thread in a process individually and then swapin the whole process if any of these fail. This allows us to move most scheduler related swap flags into td_flags. - Keep ki_sflag for backwards compat but change all in source tools to use the new and more correct location of P_INMEM. Reported by: pho Reviewed by: attilio, kib Approved by: re (kensmith)
2007-09-17 05:31:39 +00:00
if (flags & TDF_MACPEND)
To reduce per-return overhead of userret(), call into mac_thread_userret() only if PS_MACPEND is set in the process AST mask. This avoids the cost of the entry point in the common case, but requires policies interested in the userret event to set the flag (protected by the scheduler lock) if they do want the event. Since all the policies that we're working with which use mac_thread_userret() use the entry point only selectively to perform operations deferred for locking reasons, this maintains the desired semantics. Approved by: re Requested by: bde Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-11-08 19:00:17 +00:00
mac_thread_userret(td);
#endif
Move a bunch of flags from the KSE to the thread. I was in two minds as to where to put them in the first case.. I should have listenned to the other mind. Submitted by: parts by davidxu@ Reviewed by: jeff@ mini@
2003-02-17 09:55:10 +00:00
if (flags & TDF_NEEDRESCHED) {
When ktracing context switches, make sure we record involuntary switches. Otherwise, when we get a evicted from the cpu, there is no record of it. This is not a default ktrace flag.
2003-07-31 01:36:24 +00:00
#ifdef KTRACE
if (KTRPOINT(td, KTR_CSW))
Log involuntary context switches correctly.
2003-09-05 22:15:26 +00:00
ktrcsw(1, 1);
When ktracing context switches, make sure we record involuntary switches. Otherwise, when we get a evicted from the cpu, there is no record of it. This is not a default ktrace flag.
2003-07-31 01:36:24 +00:00
#endif
Commit 14/14 of sched_lock decomposition. - Use thread_lock() rather than sched_lock for per-thread scheduling sychronization. - Use the per-process spinlock rather than the sched_lock for per-process scheduling synchronization. Tested by: kris, current@ Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc. Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
thread_lock(td);
Make KSE a kernel option, turned on by default in all GENERIC kernel configs except sun4v (which doesn't process signals properly with KSE). Reviewed by: davidxu@
2006-10-26 21:42:22 +00:00
sched_prio(td, td->td_user_pri);
- Make SCHED_STATS more generic by adding a wrapper to create the variables and sysctl nodes. - In reset walk the children of kern_sched_stats and reset the counters via the oid_arg1 pointer. This allows us to add arbitrary counters to the tree and still reset them properly. - Define a set of switch types to be passed with flags to mi_switch(). These types are named SWT_*. These types correspond to SCHED_STATS counters and are automatically handled in this way. - Make the new SWT_ types more specific than the older switch stats. There are now stats for idle switches, remote idle wakeups, remote preemption ithreads idling, etc. - Add switch statistics for ULE's pickcpu algorithm. These stats include how much migration there is, how often affinity was successful, how often threads were migrated to the local cpu on wakeup, etc. Sponsored by: Nokia
2008-04-17 04:20:10 +00:00
mi_switch(SW_INVOL | SWT_NEEDRESCHED, NULL);
Commit 14/14 of sched_lock decomposition. - Use thread_lock() rather than sched_lock for per-thread scheduling sychronization. - Use the per-process spinlock rather than the sched_lock for per-process scheduling synchronization. Tested by: kris, current@ Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc. Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-05 00:00:57 +00:00
thread_unlock(td);
When ktracing context switches, make sure we record involuntary switches. Otherwise, when we get a evicted from the cpu, there is no record of it. This is not a default ktrace flag.
2003-07-31 01:36:24 +00:00
#ifdef KTRACE
if (KTRPOINT(td, KTR_CSW))
Log involuntary context switches correctly.
2003-09-05 22:15:26 +00:00
ktrcsw(0, 1);
When ktracing context switches, make sure we record involuntary switches. Otherwise, when we get a evicted from the cpu, there is no record of it. This is not a default ktrace flag.
2003-07-31 01:36:24 +00:00
#endif
Moved signal handling and rescheduling from userret() to ast() so that they aren't in the usual path of execution for syscalls and traps. The main complication for this is that we have to set flags to control ast() everywhere that changes the signal mask. Avoid locking in userret() in most of the remaining cases. Submitted by: luoqi (first part only, long ago, reorganized by me) Reminded by: dillon
2002-04-04 17:49:48 +00:00
}
- Move p->p_sigmask to td->td_sigmask. Signal masks will be per thread with a follow on commit to kern_sig.c - signotify() now operates on a thread since unmasked pending signals are stored in the thread. - PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.
2003-03-31 22:49:17 +00:00
if (flags & TDF_NEEDSIGCHK) {
Moved signal handling and rescheduling from userret() to ast() so that they aren't in the usual path of execution for syscalls and traps. The main complication for this is that we have to set flags to control ast() everywhere that changes the signal mask. Avoid locking in userret() in most of the remaining cases. Submitted by: luoqi (first part only, long ago, reorganized by me) Reminded by: dillon
2002-04-04 17:49:48 +00:00
PROC_LOCK(p);
- Merge struct procsig with struct sigacts. - Move struct sigacts out of the u-area and malloc() it using the M_SUBPROC malloc bucket. - Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(), sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared(). - Remove the p_sigignore, p_sigacts, and p_sigcatch macros. - Add a mutex to struct sigacts that protects all the members of the struct. - Add sigacts locking. - Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now that sigacts is locked. - Several in-kernel functions such as psignal(), tdsignal(), trapsignal(), and thread_stopped() are now MP safe. Reviewed by: arch@ Approved by: re (rwatson)
2003-05-13 20:36:02 +00:00
mtx_lock(&p->p_sigacts->ps_mtx);
o Change kse_thr_interrupt to allow send a signal to a specified thread, or unblock a thread in kernel, and allow UTS to specify whether syscall should be restarted. o Add ability for UTS to monitor signal comes in and removed from process, the flag PS_SIGEVENT is used to indicate the events. o Add a KMF_WAITSIGEVENT for KSE mailbox flag, UTS call kse_release with this flag set to wait for above signal event. o For SA based thread, kernel masks all signal in its signal mask, let UTS to use kse_thr_interrupt interrupt a thread, and install a signal frame in userland for the thread. o Add a tm_syncsig in thread mailbox, when a hardware trap occurs, it is used to deliver synchronous signal to userland, and upcall is schedule, so UTS can process the synchronous signal for the thread. Reviewed by: julian (mentor)
2003-06-28 08:29:05 +00:00
while ((sig = cursig(td)) != 0)
Moved signal handling and rescheduling from userret() to ast() so that they aren't in the usual path of execution for syscalls and traps. The main complication for this is that we have to set flags to control ast() everywhere that changes the signal mask. Avoid locking in userret() in most of the remaining cases. Submitted by: luoqi (first part only, long ago, reorganized by me) Reminded by: dillon
2002-04-04 17:49:48 +00:00
postsig(sig);
- Merge struct procsig with struct sigacts. - Move struct sigacts out of the u-area and malloc() it using the M_SUBPROC malloc bucket. - Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(), sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared(). - Remove the p_sigignore, p_sigacts, and p_sigcatch macros. - Add a mutex to struct sigacts that protects all the members of the struct. - Add sigacts locking. - Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now that sigacts is locked. - Several in-kernel functions such as psignal(), tdsignal(), trapsignal(), and thread_stopped() are now MP safe. Reviewed by: arch@ Approved by: re (rwatson)
2003-05-13 20:36:02 +00:00
mtx_unlock(&p->p_sigacts->ps_mtx);
Moved signal handling and rescheduling from userret() to ast() so that they aren't in the usual path of execution for syscalls and traps. The main complication for this is that we have to set flags to control ast() everywhere that changes the signal mask. Avoid locking in userret() in most of the remaining cases. Submitted by: luoqi (first part only, long ago, reorganized by me) Reminded by: dillon
2002-04-04 17:49:48 +00:00
PROC_UNLOCK(p);
}
- Add a new td flag TDF_NEEDSUSPCHK that is set whenever a thread needs to enter thread_suspend_check(). - Set TDF_ASTPENDING along with TDF_NEEDSUSPCHK so we can move the thread_suspend_check() to ast() rather than userret(). - Check TDF_NEEDSUSPCHK in the sleepq_catch_signals() optimization so that we don't miss a suspend request. If this is set use the expensive signal path. - Set NEEDSUSPCHK when creating a new thread in thr in case the creating thread is due to be suspended as well but has not yet. Reviewed by: davidxu (Authored original patch)
2008-03-21 08:23:25 +00:00
/*
* We need to check to see if we have to exit or wait due to a
* single threading requirement or some other STOP condition.
*/
if (flags & TDF_NEEDSUSPCHK) {
PROC_LOCK(p);
thread_suspend_check(0);
PROC_UNLOCK(p);
}
The biggie: Get rid of the UPAGES from the top of the per-process address space. (!) Have each process use the kernel stack and pcb in the kvm space. Since the stacks are at a different address, we cannot copy the stack at fork() and allow the child to return up through the function call tree to return to user mode - create a new execution context and have the new process begin executing from cpu_switch() and go to user mode directly. In theory this should speed up fork a bit. Context switch the tss_esp0 pointer in the common tss. This is a lot simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer to each process's tss since the esp0 pointer is a 32 bit pointer, and the sd_base setting is split into three different bit sections at non-aligned boundaries and requires a lot of twiddling to reset. The 8K of memory at the top of the process space is now empty, and unmapped (and unmappable, it's higher than VM_MAXUSER_ADDRESS). Simplity the pmap code to manage process contexts, we no longer have to double map the UPAGES, this simplifies and should measuably speed up fork(). The following parts came from John Dyson: Set PG_G on the UPAGES that are now in kernel context, and invalidate them when swapping them out. Move the upages object (upobj) from the vmspace to the proc structure. Now that the UPAGES (pcb and kernel stack) are out of user space, make rfork(..RFMEM..) do what was intended by sharing the vmspace entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00
Simplify system time accounting for profiling. Rename struct thread's td_sticks to td_pticks, we will need the other name for more appropriately named use shortly. Reduce it from uint64_t to u_int. Clear td_pticks whenever we enter the kernel instead of recording its value as reference for userret(). Use the absolute value of td->pticks in userret() and eliminate third argument.
2006-02-08 08:09:17 +00:00
userret(td, framep);
- Close races with signals and other AST's being triggered while we are in the process of exiting the kernel. The ast() function now loops as long as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with preemption disabled so that any further AST's that arrive via an interrupt will be delayed until the low-level MD code returns to user mode. - Use u_int's to store the tick counts for profiling purposes so that we do not need sched_lock just to read p_sticks. This also closes a problem where the call to addupc_task() could screw up the arithmetic due to non-atomic reads of p_sticks. - Axe need_proftick(), aston(), astoff(), astpending(), need_resched(), clear_resched(), and resched_wanted() in favor of direct bit operations on p_sflag. - Fix up locking with sched_lock some. In addupc_intr(), use sched_lock to ensure pr_addr and pr_ticks are updated atomically with setting PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing PS_OWEUPC. We also do not grab the lock just to test a flag. - Simplify the handling of Giant in ast() slightly. Reviewed by: bde (mostly)
2001-08-10 22:53:32 +00:00
mtx_assert(&Giant, MA_NOTOWNED);
The biggie: Get rid of the UPAGES from the top of the per-process address space. (!) Have each process use the kernel stack and pcb in the kvm space. Since the stacks are at a different address, we cannot copy the stack at fork() and allow the child to return up through the function call tree to return to user mode - create a new execution context and have the new process begin executing from cpu_switch() and go to user mode directly. In theory this should speed up fork a bit. Context switch the tss_esp0 pointer in the common tss. This is a lot simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer to each process's tss since the esp0 pointer is a 32 bit pointer, and the sd_base setting is split into three different bit sections at non-aligned boundaries and requires a lot of twiddling to reset. The 8K of memory at the top of the process space is now empty, and unmapped (and unmappable, it's higher than VM_MAXUSER_ADDRESS). Simplity the pmap code to manage process contexts, we no longer have to double map the UPAGES, this simplifies and should measuably speed up fork(). The following parts came from John Dyson: Set PG_G on the UPAGES that are now in kernel context, and invalidate them when swapping them out. Move the upages object (upobj) from the vmspace to the proc structure. Now that the UPAGES (pcb and kernel stack) are out of user space, make rfork(..RFMEM..) do what was intended by sharing the vmspace entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00
}
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