9ed346bab0
mtx_enter(lock, type) becomes:
mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)
similarily, for releasing a lock, we now have:
mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.
The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.
Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:
MTX_QUIET and MTX_NOSWITCH
The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:
mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.
Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.
Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.
Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.
Finally, caught up to the interface changes in all sys code.
Contributors: jake, jhb, jasone (in no particular order)
390 lines
8.8 KiB
C
390 lines
8.8 KiB
C
/*
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* Copyright (c) 1982, 1986, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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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, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, 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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER 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
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* SUCH DAMAGE.
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*
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* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
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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/ktr.h>
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#include <sys/proc.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/lock.h>
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#include <sys/resourcevar.h>
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#include <sys/vnode.h>
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#include <vm/vm.h>
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#include <vm/vm_page.h>
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#include <vm/vm_map.h>
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static void uio_yield __P((void));
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int
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uiomove(cp, n, uio)
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register caddr_t cp;
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register int n;
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register struct uio *uio;
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{
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register struct iovec *iov;
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u_int cnt;
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int error = 0;
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int save = 0;
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KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
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("uiomove: mode"));
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KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_procp == curproc,
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("uiomove proc"));
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if (curproc) {
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save = curproc->p_flag & P_DEADLKTREAT;
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curproc->p_flag |= P_DEADLKTREAT;
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}
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while (n > 0 && uio->uio_resid) {
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iov = uio->uio_iov;
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cnt = iov->iov_len;
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if (cnt == 0) {
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uio->uio_iov++;
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uio->uio_iovcnt--;
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continue;
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}
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if (cnt > n)
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cnt = n;
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switch (uio->uio_segflg) {
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case UIO_USERSPACE:
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case UIO_USERISPACE:
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if (ticks - PCPU_GET(switchticks) >= hogticks)
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uio_yield();
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if (uio->uio_rw == UIO_READ)
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error = copyout(cp, iov->iov_base, cnt);
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else
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error = copyin(iov->iov_base, cp, cnt);
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if (error)
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break;
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break;
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case UIO_SYSSPACE:
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if (uio->uio_rw == UIO_READ)
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bcopy((caddr_t)cp, iov->iov_base, cnt);
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else
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bcopy(iov->iov_base, (caddr_t)cp, cnt);
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break;
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case UIO_NOCOPY:
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break;
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}
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iov->iov_base += cnt;
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iov->iov_len -= cnt;
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uio->uio_resid -= cnt;
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uio->uio_offset += cnt;
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cp += cnt;
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n -= cnt;
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}
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if (curproc)
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curproc->p_flag = (curproc->p_flag & ~P_DEADLKTREAT) | save;
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return (error);
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}
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int
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uiomoveco(cp, n, uio, obj)
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caddr_t cp;
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int n;
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struct uio *uio;
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struct vm_object *obj;
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{
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struct iovec *iov;
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u_int cnt;
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int error;
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KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
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("uiomoveco: mode"));
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KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_procp == curproc,
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("uiomoveco proc"));
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while (n > 0 && uio->uio_resid) {
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iov = uio->uio_iov;
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cnt = iov->iov_len;
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if (cnt == 0) {
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uio->uio_iov++;
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uio->uio_iovcnt--;
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continue;
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}
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if (cnt > n)
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cnt = n;
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switch (uio->uio_segflg) {
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case UIO_USERSPACE:
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case UIO_USERISPACE:
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if (ticks - PCPU_GET(switchticks) >= hogticks)
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uio_yield();
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if (uio->uio_rw == UIO_READ) {
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#ifdef ENABLE_VFS_IOOPT
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if (vfs_ioopt && ((cnt & PAGE_MASK) == 0) &&
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((((intptr_t) iov->iov_base) & PAGE_MASK) == 0) &&
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((uio->uio_offset & PAGE_MASK) == 0) &&
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((((intptr_t) cp) & PAGE_MASK) == 0)) {
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error = vm_uiomove(&curproc->p_vmspace->vm_map, obj,
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uio->uio_offset, cnt,
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(vm_offset_t) iov->iov_base, NULL);
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} else
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#endif
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{
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error = copyout(cp, iov->iov_base, cnt);
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}
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} else {
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error = copyin(iov->iov_base, cp, cnt);
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}
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if (error)
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return (error);
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break;
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case UIO_SYSSPACE:
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if (uio->uio_rw == UIO_READ)
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bcopy((caddr_t)cp, iov->iov_base, cnt);
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else
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bcopy(iov->iov_base, (caddr_t)cp, cnt);
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break;
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case UIO_NOCOPY:
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break;
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}
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iov->iov_base += cnt;
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iov->iov_len -= cnt;
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uio->uio_resid -= cnt;
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uio->uio_offset += cnt;
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cp += cnt;
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n -= cnt;
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}
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return (0);
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}
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#ifdef ENABLE_VFS_IOOPT
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int
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uioread(n, uio, obj, nread)
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int n;
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struct uio *uio;
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struct vm_object *obj;
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int *nread;
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{
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int npagesmoved;
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struct iovec *iov;
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u_int cnt, tcnt;
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int error;
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*nread = 0;
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if (vfs_ioopt < 2)
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return 0;
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error = 0;
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while (n > 0 && uio->uio_resid) {
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iov = uio->uio_iov;
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cnt = iov->iov_len;
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if (cnt == 0) {
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uio->uio_iov++;
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uio->uio_iovcnt--;
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continue;
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}
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if (cnt > n)
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cnt = n;
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if ((uio->uio_segflg == UIO_USERSPACE) &&
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((((intptr_t) iov->iov_base) & PAGE_MASK) == 0) &&
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((uio->uio_offset & PAGE_MASK) == 0) ) {
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if (cnt < PAGE_SIZE)
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break;
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cnt &= ~PAGE_MASK;
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if (ticks - PCPU_GET(switchticks) >= hogticks)
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uio_yield();
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error = vm_uiomove(&curproc->p_vmspace->vm_map, obj,
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uio->uio_offset, cnt,
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(vm_offset_t) iov->iov_base, &npagesmoved);
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if (npagesmoved == 0)
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break;
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tcnt = npagesmoved * PAGE_SIZE;
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cnt = tcnt;
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if (error)
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break;
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iov->iov_base += cnt;
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iov->iov_len -= cnt;
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uio->uio_resid -= cnt;
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uio->uio_offset += cnt;
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*nread += cnt;
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n -= cnt;
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} else {
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break;
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}
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}
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return error;
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}
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#endif
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/*
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* Give next character to user as result of read.
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*/
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int
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ureadc(c, uio)
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register int c;
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register struct uio *uio;
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{
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register struct iovec *iov;
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again:
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if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
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panic("ureadc");
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iov = uio->uio_iov;
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if (iov->iov_len == 0) {
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uio->uio_iovcnt--;
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uio->uio_iov++;
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goto again;
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}
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switch (uio->uio_segflg) {
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case UIO_USERSPACE:
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if (subyte(iov->iov_base, c) < 0)
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return (EFAULT);
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break;
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case UIO_SYSSPACE:
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*iov->iov_base = c;
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break;
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case UIO_USERISPACE:
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if (suibyte(iov->iov_base, c) < 0)
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return (EFAULT);
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break;
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case UIO_NOCOPY:
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break;
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}
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iov->iov_base++;
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iov->iov_len--;
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uio->uio_resid--;
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uio->uio_offset++;
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return (0);
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}
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/*
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* General routine to allocate a hash table.
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*/
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void *
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hashinit(elements, type, hashmask)
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int elements;
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struct malloc_type *type;
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u_long *hashmask;
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{
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long hashsize;
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LIST_HEAD(generic, generic) *hashtbl;
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int i;
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if (elements <= 0)
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panic("hashinit: bad elements");
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for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
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continue;
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hashsize >>= 1;
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hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
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for (i = 0; i < hashsize; i++)
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LIST_INIT(&hashtbl[i]);
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*hashmask = hashsize - 1;
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return (hashtbl);
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}
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static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
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2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
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7159, 7673, 8191, 12281, 16381, 24571, 32749 };
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#define NPRIMES (sizeof(primes) / sizeof(primes[0]))
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/*
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* General routine to allocate a prime number sized hash table.
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*/
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void *
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phashinit(elements, type, nentries)
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int elements;
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struct malloc_type *type;
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u_long *nentries;
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{
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long hashsize;
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LIST_HEAD(generic, generic) *hashtbl;
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int i;
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if (elements <= 0)
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panic("phashinit: bad elements");
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for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
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i++;
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if (i == NPRIMES)
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break;
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hashsize = primes[i];
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}
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hashsize = primes[i - 1];
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hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
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for (i = 0; i < hashsize; i++)
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LIST_INIT(&hashtbl[i]);
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*nentries = hashsize;
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return (hashtbl);
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}
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static void
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uio_yield()
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{
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struct proc *p;
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int s;
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p = curproc;
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s = splhigh();
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mtx_lock_spin(&sched_lock);
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DROP_GIANT_NOSWITCH();
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p->p_priority = p->p_usrpri;
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setrunqueue(p);
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p->p_stats->p_ru.ru_nivcsw++;
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mi_switch();
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mtx_unlock_spin(&sched_lock);
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PICKUP_GIANT();
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splx(s);
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}
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