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freebsd-nq/include/sys/condvar.h

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Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
/*****************************************************************************\
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
Go through and add a header with the proper UCRL number. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@114 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-26 04:38:26 +00:00
* UCRL-CODE-235197
*
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
* This file is part of the SPL, Solaris Porting Layer.
Refresh links to web site Update links to refer to the official ZFS on Linux website instead of @behlendorf's personal fork on github. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-05 01:26:55 +00:00
* For details, see <http://zfsonlinux.org/>.
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
Go through and add a header with the proper UCRL number. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@114 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-26 04:38:26 +00:00
*
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
* The SPL is distributed in the hope that it will be useful, but WITHOUT
Go through and add a header with the proper UCRL number. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@114 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-26 04:38:26 +00:00
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
\*****************************************************************************/
Go through and add a header with the proper UCRL number. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@114 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-26 04:38:26 +00:00
Minor nit, SOLARIS should be SPL git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@17 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-28 00:52:31 +00:00
#ifndef _SPL_CONDVAR_H
#define _SPL_CONDVAR_H
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
Lots of build fixes. This is turning out to be a very good idea since it forcefully codifing the ABI. Since the shim layer is no longer linked at build time in to the test suite we can;'t cut any corners and get away with it. Everything is working now with the exception of sorting setting Module.symvers properly. This may take a little Makefile reorg. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@5 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-27 19:09:51 +00:00
#include <linux/module.h>
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
#include <linux/wait.h>
Emulate illumos interface cv_timedwait_hires() Needed for Illumos #3582. This interface is supposed to support a variable-resolution timeout with nanosecond granularity. This implementation rounds up to microsecond resolution, as nanosecond- precision timing is rarely needed for real-world performance tuning and may incur unnecessary busy-waiting. usleep_range() is used if available, otherwise udelay() or msleep() are used depending on the length of the delay interval. Add flags from sys/callo.h as these are used to control the behavior of cv_timedwait_hires(). Specifically, CALLOUT_FLAG_ABSOLUTE Normally, the expiration passed to the timeout API functions is an expiration interval. If this flag is specified, then it is interpreted as the expiration time itself. CALLOUT_FLAG_ROUNDUP Roundup the expiration time to the next resolution boundary. If this flag is not specified, the expiration time is rounded down. References: https://www.illumos.org/issues/3582 illumos/illumos-gate@0689f76 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #304
2013-11-01 20:37:58 +00:00
#include <linux/delay_compat.h>
Reimplement mutexs for Linux lock profiling/analysis For a generic explanation of why mutexs needed to be reimplemented to work with the kernel lock profiling see commits: e811949a57044d60d12953c5c3b808a79a7d36ef and d28db80fd0fd4fd63aec09037c44408e51a222d6 The specific changes made to the mutex implemetation are as follows. The Linux mutex structure is now directly embedded in the kmutex_t. This allows a kmutex_t to be directly case to a mutex struct and passed directly to the Linux primative. Just like with the rwlocks it is critical that these functions be implemented as '#defines to ensure the location information is preserved. The preprocessor can then do a direct replacement of the Solaris primative with the linux primative. Just as with the rwlocks we need to track the lock owner. Here things get a little more interesting because depending on your kernel version, and how you've built your kernel Linux may already do this for you. If your running a 2.6.29 or newer kernel on a SMP system the lock owner will be tracked. This was added to Linux to support adaptive mutexs, more on that shortly. Alternately, your kernel might track the lock owner if you've set CONFIG_DEBUG_MUTEXES in the kernel build. If neither of the above things is true for your kernel the kmutex_t type will include and track the lock owner to ensure correct behavior. This is all handled by a new autoconf check called SPL_AC_MUTEX_OWNER. Concerning adaptive mutexs these are a very recent development and they did not make it in to either the latest FC11 of SLES11 kernels. Ideally, I'd love to see this kernel change appear in one of these distros because it does help performance. From Linux kernel commit: 0d66bf6d3514b35eb6897629059443132992dbd7 "Testing with Ingo's test-mutex application... gave a 345% boost for VFS scalability on my testbox" However, if you don't want to backport this change yourself you can still simply export the task_curr() symbol. The kmutex_t implementation will use this symbol when it's available to provide it's own adaptive mutexs. Finally, DEBUG_MUTEX support was removed including the proc handlers. This was done because now that we are cleanly integrated with the kernel profiling all this information and much much more is available in debug kernel builds. This code was now redundant. Update mutexs validated on: - SLES10 (ppc64) - SLES11 (x86_64) - CHAOS4.2 (x86_64) - RHEL5.3 (x86_64) - RHEL6 (x86_64) - FC11 (x86_64)
2009-09-25 21:47:01 +00:00
#include <sys/kmem.h>
Rework condition variable implementation to be consistent with other primitive implementations. Additionally ensure that GFP_ATOMIC is use for allocations when in interrupt context. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@108 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-15 17:10:30 +00:00
#include <sys/mutex.h>
Emulate illumos interface cv_timedwait_hires() Needed for Illumos #3582. This interface is supposed to support a variable-resolution timeout with nanosecond granularity. This implementation rounds up to microsecond resolution, as nanosecond- precision timing is rarely needed for real-world performance tuning and may incur unnecessary busy-waiting. usleep_range() is used if available, otherwise udelay() or msleep() are used depending on the length of the delay interval. Add flags from sys/callo.h as these are used to control the behavior of cv_timedwait_hires(). Specifically, CALLOUT_FLAG_ABSOLUTE Normally, the expiration passed to the timeout API functions is an expiration interval. If this flag is specified, then it is interpreted as the expiration time itself. CALLOUT_FLAG_ROUNDUP Roundup the expiration time to the next resolution boundary. If this flag is not specified, the expiration time is rounded down. References: https://www.illumos.org/issues/3582 illumos/illumos-gate@0689f76 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #304
2013-11-01 20:37:58 +00:00
#include <sys/callo.h>
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
Public Release Prep Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added standardized headers to all source file to clearly indicate the copyright, license, and to give credit where credit is due.
2010-05-17 22:18:00 +00:00
/*
* The kcondvar_t struct is protected by mutex taken externally before
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
* calling any of the wait/signal funs, and passed into the wait funs.
*/
#define CV_MAGIC 0x346545f4
Condition variable reference counts Reference count every entry and exit from the condition variable functions: cv_wait(), cv_wait_timeout(), cv_signal(), cv_broadcast(). This allows us to safely block in cv_destroy() until all consumers have been scheduled and are no longer accessing the condition variable memory. In addition poison the magic value at the start of cv_destroy() to ensure there are never any new callers after cv_destroy() is called. The consumer is responsible for ensuring this never occurs. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-05 17:04:50 +00:00
#define CV_DESTROY 0x346545f5
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
typedef struct {
int cv_magic;
wait_queue_head_t cv_event;
Block in cv_destroy() on all waiters Previously we would ASSERT in cv_destroy() if it was ever called with active waiters. However, I've now seen several instances in OpenSolaris code where they do the following: cv_broadcast(); cv_destroy(); This leaves no time for active waiters to be woken up and scheduled and we trip the ASSERT. This has not been observed to be an issue on OpenSolaris because their cv_destroy() basically does nothing. They still do run the risk of the memory being free'd after the cv_destroy() and hitting a bad paging request. But in practice this race is so small and unlikely it either doesn't happen, or is so unlikely when it does happen the root cause has not yet been identified. Rather than risk the same issue in our code this change updates cv_destroy() to block until all waiters have been woken and scheduled. This may take some time because each waiter must acquire the mutex. This change may have an impact on performance for frequently created and destroyed condition variables. That however is a price worth paying it avoid crashing your system. If performance issues are observed they can be addressed by the caller.
2011-02-04 22:09:08 +00:00
wait_queue_head_t cv_destroy;
Condition variable reference counts Reference count every entry and exit from the condition variable functions: cv_wait(), cv_wait_timeout(), cv_signal(), cv_broadcast(). This allows us to safely block in cv_destroy() until all consumers have been scheduled and are no longer accessing the condition variable memory. In addition poison the magic value at the start of cv_destroy() to ensure there are never any new callers after cv_destroy() is called. The consumer is responsible for ensuring this never occurs. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-05 17:04:50 +00:00
atomic_t cv_refs;
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
atomic_t cv_waiters;
Rework condition variable implementation to be consistent with other primitive implementations. Additionally ensure that GFP_ATOMIC is use for allocations when in interrupt context. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@108 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-15 17:10:30 +00:00
kmutex_t *cv_mutex;
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
} kcondvar_t;
typedef enum { CV_DEFAULT=0, CV_DRIVER } kcv_type_t;
Rework condition variable implementation to be consistent with other primitive implementations. Additionally ensure that GFP_ATOMIC is use for allocations when in interrupt context. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@108 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-15 17:10:30 +00:00
extern void __cv_init(kcondvar_t *cvp, char *name, kcv_type_t type, void *arg);
extern void __cv_destroy(kcondvar_t *cvp);
extern void __cv_wait(kcondvar_t *cvp, kmutex_t *mp);
Add cv_wait_io() to account I/O time Under Linux when a task is waiting on I/O it should call the io_schedule() function for proper accounting. The Solaris cv_wait() function provides no way to specify what the cv is waiting on therefore cv_wait_io() is introduced. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #206
2012-12-21 02:29:16 +00:00
extern void __cv_wait_io(kcondvar_t *cvp, kmutex_t *mp);
Add cv_wait_interruptible() function. This is a minor extension to the condition variable API to allow for reasonable signal handling on Linux. The cv_wait() function by definition must wait unconditionally for cv_signal()/cv_broadcast() before waking it. This makes it impossible to woken by a signal such as SIGTERM. The cv_wait_interruptible() function was added to handle this case. It behaves identically to cv_wait() with the exception that it waits interruptibly allowing a signal to wake it up. This means you do need to be careful and check issig() after waking.
2010-05-14 16:24:51 +00:00
extern void __cv_wait_interruptible(kcondvar_t *cvp, kmutex_t *mp);
extern clock_t __cv_timedwait(kcondvar_t *cvp, kmutex_t *mp, clock_t exp_time);
Add cv_timedwait_interruptible() function The cv_timedwait() function by definition must wait unconditionally for cv_signal()/cv_broadcast() before waking. This causes processes to go in the D state which increases the load average. The load average is the summation of processes in D state and run queue. To avoid this it can be desirable to sleep interruptibly. These processes do not count against the load average but may be woken by a signal. It is up to the caller to determine why the process was woken it may be for one of three reasons. 1) cv_signal()/cv_broadcast() 2) the timeout expired 3) a signal was received Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-12-06 11:35:58 +00:00
extern clock_t __cv_timedwait_interruptible(kcondvar_t *cvp, kmutex_t *mp,
clock_t exp_time);
Emulate illumos interface cv_timedwait_hires() Needed for Illumos #3582. This interface is supposed to support a variable-resolution timeout with nanosecond granularity. This implementation rounds up to microsecond resolution, as nanosecond- precision timing is rarely needed for real-world performance tuning and may incur unnecessary busy-waiting. usleep_range() is used if available, otherwise udelay() or msleep() are used depending on the length of the delay interval. Add flags from sys/callo.h as these are used to control the behavior of cv_timedwait_hires(). Specifically, CALLOUT_FLAG_ABSOLUTE Normally, the expiration passed to the timeout API functions is an expiration interval. If this flag is specified, then it is interpreted as the expiration time itself. CALLOUT_FLAG_ROUNDUP Roundup the expiration time to the next resolution boundary. If this flag is not specified, the expiration time is rounded down. References: https://www.illumos.org/issues/3582 illumos/illumos-gate@0689f76 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #304
2013-11-01 20:37:58 +00:00
extern clock_t cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp,
hrtime_t tim, hrtime_t res, int flag);
Rework condition variable implementation to be consistent with other primitive implementations. Additionally ensure that GFP_ATOMIC is use for allocations when in interrupt context. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@108 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-05-15 17:10:30 +00:00
extern void __cv_signal(kcondvar_t *cvp);
extern void __cv_broadcast(kcondvar_t *cvp);
Remove condition variable names Long ago I added support to the spl for condition variable names because I thought they might be needed. It turns out they aren't. In fact the official Solaris cv_init(9F) man page discourages their use in the kernel. cv_init(9F) Parameters name - Descriptive string. This is obsolete and should be NULL. (Non-NULL strings are legal, but they're a waste of kernel memory.) Therefore, I'm removing them from the spl to reclaim this memory and adding an ASSERT() to ensure no new consumers are added which make use of the name. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-04-06 18:29:23 +00:00
#define cv_init(cvp, name, type, arg) __cv_init(cvp, name, type, arg)
Add cv_timedwait_interruptible() function The cv_timedwait() function by definition must wait unconditionally for cv_signal()/cv_broadcast() before waking. This causes processes to go in the D state which increases the load average. The load average is the summation of processes in D state and run queue. To avoid this it can be desirable to sleep interruptibly. These processes do not count against the load average but may be woken by a signal. It is up to the caller to determine why the process was woken it may be for one of three reasons. 1) cv_signal()/cv_broadcast() 2) the timeout expired 3) a signal was received Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-12-06 11:35:58 +00:00
#define cv_destroy(cvp) __cv_destroy(cvp)
#define cv_wait(cvp, mp) __cv_wait(cvp, mp)
Add cv_wait_io() to account I/O time Under Linux when a task is waiting on I/O it should call the io_schedule() function for proper accounting. The Solaris cv_wait() function provides no way to specify what the cv is waiting on therefore cv_wait_io() is introduced. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #206
2012-12-21 02:29:16 +00:00
#define cv_wait_io(cvp, mp) __cv_wait_io(cvp, mp)
Add cv_timedwait_interruptible() function The cv_timedwait() function by definition must wait unconditionally for cv_signal()/cv_broadcast() before waking. This causes processes to go in the D state which increases the load average. The load average is the summation of processes in D state and run queue. To avoid this it can be desirable to sleep interruptibly. These processes do not count against the load average but may be woken by a signal. It is up to the caller to determine why the process was woken it may be for one of three reasons. 1) cv_signal()/cv_broadcast() 2) the timeout expired 3) a signal was received Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-12-06 11:35:58 +00:00
#define cv_wait_interruptible(cvp, mp) __cv_wait_interruptible(cvp,mp)
#define cv_timedwait(cvp, mp, t) __cv_timedwait(cvp, mp, t)
#define cv_timedwait_interruptible(cvp, mp, t) \
__cv_timedwait_interruptible(cvp, mp, t)
#define cv_signal(cvp) __cv_signal(cvp)
#define cv_broadcast(cvp) __cv_broadcast(cvp)
Initial commit. All spl source written up to this point wrapped in an initial reasonable autoconf style build system. This does not yet build but the configure system does appear to work properly and integrate with the kernel. Hopefully the next commit gets us back to a buildable version we can run the test suite against. git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@1 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-26 20:36:04 +00:00
Minor nit, SOLARIS should be SPL git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@17 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
2008-02-28 00:52:31 +00:00
#endif /* _SPL_CONDVAR_H */
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