Select Git revision
Search by author
- Any Author
- authors
-
Abhiram Balasubramanian abhiram
-
Anton Burtsev
aburtsev
-
Charlie Jacobsen cjacobsen
-
David Detweiler ddetweiler
-
David Johnson johnsond
-
Michael Quigley MichaelQuigley
-
Mike Hibler hibler
-
Robert Ricci ricci
-
Sarah Spall spall
-
Scotty Bauer ScottyB
-
Vikram Narayanan vikram
- May 23, 2011
-
-
Thomas Gleixner authored
Instead of iterating over all possible timer bases avoid it by marking the active bases in the cpu base. Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
Peter Zijlstra <peterz@infradead.org>
-
- Mar 31, 2011
-
-
Lucas De Marchi authored
Fixes generated by 'codespell' and manually reviewed. Signed-off-by:Lucas De Marchi <lucas.demarchi@profusion.mobi>
-
- Feb 02, 2011
-
-
Thomas Gleixner authored
Rename register_posix_clock() to posix_timers_register_clock(). That's what the function really does. As a side effect this cleans up the posix_clock namespace for the upcoming dynamic posix_clock infrastructure. Signed-off-by:
Richard Cochran <richard.cochran@omicron.at> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <alpine.LFD.2.00.1102021222240.31804@localhost6.localdomain6>
-
Thomas Gleixner authored
All functions are accessed via clock_posix_cpu now. So make them static. Signed-off-by:
John Stultz <johnstul@us.ibm.com> Tested-by:
-
Thomas Gleixner authored
Use the new kclock decoding function in clock_settime and cleanup all kclocks which use the default functions. Rename the misnomed common_clock_set() to posix_clock_realtime_set(). Signed-off-by:
-
Thomas Gleixner authored
CLOCK_THREAD_CPUTIME_ID implements stub functions for nanosleep and nanosleep_restart, which return -EINVAL. That return value is wrong. The correct return value is -ENOTSUP. Remove the stubs and let the new dispatch code return the correct error code. Signed-off-by:
-
Thomas Gleixner authored
posix timers still use the legacy arg0-arg3 members of restart_block. Use restart_block.nanosleep instead Signed-off-by:
-
Thomas Gleixner authored
The CLOCK_DISPATCH() macro is a horrible magic. We call common functions if a function pointer is not set. That's just backwards. To support dynamic file decriptor based clocks we need to cleanup that dispatch logic. Create a k_clock struct clock_posix_cpu which has all the posix-cpu-timer functions filled in. After the cleanup the functions can be made static. Signed-off-by:
-
Thomas Gleixner authored
Cosmetic. No functional change Signed-off-by:
-
- Nov 10, 2010
-
-
Sergey Senozhatsky authored
Commit 4221a991 "Add RCU check for find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns. Add rcu_read_lock/rcu_read_unlock to call find_task_by_vpid. Tetsuo Handa wrote: | Quoting from one of posts in that thead | http://kerneltrap.org/mailarchive/linux-kernel/2010/2/8/4536388 | || Usually tasklist gives enough protection, but if copy_process() fails || it calls free_pid() lockless and does call_rcu(delayed_put_pid(). || This means, without rcu lock find_pid_ns() can't scan the hash table || safely. Thomas Gleixner wrote: | We can remove the tasklist_lock while at it. rcu_read_lock is enough. Patch also replaces thread_group_leader with has_group_leader_pid in accordance to comment by Oleg Nesterov: | ... thread_group_leader() check is not relaible without | tasklist. If we race with de_thread() find_task_by_vpid() can find | the new leader before it updates its ->group_leader. | | perhaps it makes sense to change posix_cpu_timer_create() to use | has_group_leader_pid() instead, just to make this code not look racy | and avoid adding new problems. Signed-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Reviewed-by:
Oleg Nesterov <oleg@redhat.com> LKML-Reference: <20101103165256.GD30053@swordfish.minsk.epam.com> Signed-off-by:
-
- Jul 16, 2010
-
-
Jiri Slaby authored
Add task_struct as a parameter to update_rlimit_cpu to be able to set rlimit_cpu of different task than current. Signed-off-by:
Jiri Slaby <jirislaby@gmail.com> Acked-by:
James Morris <jmorris@namei.org>
-
- Jun 18, 2010
-
-
Oleg Nesterov authored
fastpath_timer_check()->thread_group_cputimer() is racy and unneeded. It is racy because another thread can clear ->running before thread_group_cputimer() takes cputimer->lock. In this case thread_group_cputimer() will set ->running = true again and call thread_group_cputime(). But since we do not hold tasklist or siglock, we can race with fork/exit and copy the wrong results into cputimer->cputime. It is unneeded because if ->running == true we can just use the numbers in cputimer->cputime we already have. Change fastpath_timer_check() to copy cputimer->cputime into the local variable under cputimer->lock. We do not re-check ->running under cputimer->lock, run_posix_cpu_timers() does this check later. Note: we can add more optimizations on top of this change. Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100611180446.GA13025@redhat.com> Signed-off-by:
Ingo Molnar <mingo@elte.hu>
-
Oleg Nesterov authored
run_posix_cpu_timers() doesn't work if current has already passed exit_notify(). This was needed to prevent the races with do_wait(). Since ea6d290c ->signal is always valid and can't go away. We can remove the "tsk->exit_state == 0" in fastpath_timer_check() and convert run_posix_cpu_timers() to use lock_task_sighand(). Note: it makes sense to take group_leader's sighand instead, the sub-thread still uses CPU after release_task(). But we need more changes to do this. Signed-off-by:
-
Oleg Nesterov authored
thread_group_cputime() looks as if it is rcu-safe, but in fact this was wrong until ea6d290c which pins task->signal to task_struct. It checks ->sighand != NULL under rcu, but this can't help if ->signal can go away. Fortunately the caller either holds ->siglock, or it is fastpath_timer_check() which uses current and checks exit_state == 0. - Since ea6d290c commit tsk->signal is stable, we can read it first and avoid the initialization from INIT_CPUTIME. - Even if tsk->signal is always valid, we still have to check it is safe to use next_thread() under rcu_read_lock(). Currently the code checks ->sighand != NULL, change it to use pid_alive() which is commonly used to ensure the task wasn't unhashed before we take rcu_read_lock(). Add the comment to explain this check. - Change the main loop to use the while_each_thread() helper. Signed-off-by:
-
- May 27, 2010
-
-
Oleg Nesterov authored
Preparation to make task->signal immutable, no functional changes. posix-cpu-timers.c checks task->signal != NULL to ensure this task is alive and didn't pass __exit_signal(). This is correct but we are going to change the lifetime rules for ->signal and never reset this pointer. Change the code to check ->sighand instead, it doesn't matter which pointer we check under tasklist, they both are cleared simultaneously. As Roland pointed out, some of these changes are not strictly needed and probably it makes sense to revert them later, when ->signal will be pinned to task_struct. But this patch tries to ensure the subsequent changes in fork/exit can't make any visible impact on posix cpu timers. Signed-off-by:
Roland McGrath <roland@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
- May 10, 2010
-
-
Stanislaw Gruszka authored
We can optimize and simplify things taking into account signal->cputimer is always running when we have configured any process wide cpu timer. In check_process_timers(), we don't have to check if new updated value of signal->cputime_expires is smaller, since we maintain new first expiration time ({prof,virt,sched}_expires) in code flow and all other writes to expiration cache are protected by sighand->siglock . Signed-off-by:Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by:
-
- Mar 12, 2010
-
-
Stanislaw Gruszka authored
Spread p->sighand->siglock locking scope to make sure that fastpath_timer_check() never iterates over all threads. Without locking there is small possibility that signal->cputimer will stop running while we write values to signal->cputime_expires. Calling thread_group_cputime() from fastpath_timer_check() is not only bad because it is slow, also it is racy with __exit_signal() which can lead to invalid signal->{s,u}time values. Signed-off-by: -
Stanislaw Gruszka authored
When user sets up a timer without associated signal and process does not use any other cpu timers and does not exit, tsk->signal->cputimer is enabled and running forever. Avoid running the timer for no reason. I used below program to check patch does not break current user space visible behavior. #include <sys/time.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h> #include <unistd.h> #include <assert.h> void consume_cpu(void) { int i = 0; int count = 0; for(i=0; i<100000000; i++) count++; } int main(void) { int i; struct sigaction act; struct sigevent evt = { }; timer_t tid; struct itimerspec spec = { }; evt.sigev_notify = SIGEV_NONE; assert(timer_create(CLOCK_PROCESS_CPUTIME_ID, &evt, &tid) == 0); spec.it_value.tv_sec = 10; assert(timer_settime(tid, 0, &spec, NULL) == 0); for (i = 0; i < 30; i++) { consume_cpu(); memset(&spec, 0, sizeof(spec)); assert(timer_gettime(tid, &spec) == 0); printf("%lu.%09lu\n", (unsigned long) spec.it_value.tv_sec, (unsigned long) spec.it_value.tv_nsec); } assert(timer_delete(tid) == 0); return 0; } Signed-off-by: -
Stanislaw Gruszka authored
According POSIX we need to correctly set old timer it_interval value when user request that in timer_settime(). Tested using below program. #include <sys/time.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <time.h> #include <unistd.h> #include <assert.h> int main(void) { struct sigaction act; struct sigevent evt = { }; timer_t tid; struct itimerspec spec, u_spec, k_spec; evt.sigev_notify = SIGEV_SIGNAL; evt.sigev_signo = SIGPROF; assert(timer_create(CLOCK_PROCESS_CPUTIME_ID, &evt, &tid) == 0); spec.it_value.tv_sec = 1; spec.it_value.tv_nsec = 2; spec.it_interval.tv_sec = 3; spec.it_interval.tv_nsec = 4; u_spec = spec; assert(timer_settime(tid, 0, &spec, NULL) == 0); spec.it_value.tv_sec = 5; spec.it_value.tv_nsec = 6; spec.it_interval.tv_sec = 7; spec.it_interval.tv_nsec = 8; assert(timer_settime(tid, 0, &spec, &k_spec) == 0); #define PRT(val) printf(#val ":\t%d/%d\n", (int) u_spec.val, (int) k_spec.val) PRT(it_value.tv_sec); PRT(it_value.tv_nsec); PRT(it_interval.tv_sec); PRT(it_interval.tv_nsec); return 0; } Signed-off-by: -
Stanislaw Gruszka authored
Signed-off-by:
-
Stanislaw Gruszka authored
Let always set signal->cputime_expires expiration cache when setting new itimer, POSIX 1.b timer, and RLIMIT_CPU. Since we are initializing prof_exp expiration cache during fork(), this allows to remove "RLIMIT_CPU != inf" check from fastpath_timer_check() and do some other cleanups. Checked against regression using test cases from: http://marc.info/?l=linux-kernel&m=123749066504641&w=4 http://marc.info/?l=linux-kernel&m=123811277916642&w=2 Signed-off-by:
-
Stanislaw Gruszka authored
When a process deletes cpu timer or a timer expires we do not clear the expiration cache sig->cputimer_expires. As a result the fastpath_timer_check() which prevents us to loop over all threads in case no timer is active is not working and we run the slow path needlessly on every tick. Zero sig->cputimer_expires in stop_process_timers(). Signed-off-by:
-
- Mar 06, 2010
-
-
Jiri Slaby authored
Make sure compiler won't do weird things with limits. E.g. fetching them twice may return 2 different values after writable limits are implemented. I.e. either use rlimit helpers added in commit 3e10e716 ("resource: add helpers for fetching rlimits") or ACCESS_ONCE if not applicable. Signed-off-by:
Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by:
-
Jiri Slaby authored
Fetch rlimit (both hard and soft) values only once and work on them. It removes many accesses through sig structure and makes the code cleaner. Mostly a preparation for writable resource limits support. Signed-off-by:
-
- Nov 18, 2009
-
-
Stanislaw Gruszka authored
We have already new_timer initialized to all-zeros hence in function initializations are not needed. Document function expectation about new_timer argument as well. Signed-off-by:
-
- Aug 29, 2009
-
-
Xiao Guangrong authored
Add tracepoints for all itimer variants: ITIMER_REAL, ITIMER_VIRTUAL and ITIMER_PROF. [ tglx: Fixed comments and made the output more readable, parseable and consistent. Replaced pid_vnr by pid_nr because the hrtimer callback can happen in any namespace ] Signed-off-by:
Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Anton Blanchard <anton@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Zhaolei <zhaolei@cn.fujitsu.com> LKML-Reference: <4A7F8B6E.2010109@cn.fujitsu.com> Signed-off-by:
-
- Aug 08, 2009
-
-
Stanislaw Gruszka authored
When the process exits we don't have to run new cputimer nor use running one (as it not accounts when tsk->exit_state != 0) to get process CPU times. As there is only one thread we can just use CPU times fields from task and signal structs. Signed-off-by:
-
- Aug 03, 2009
-
-
Stanislaw Gruszka authored
For powerpc with CONFIG_VIRT_CPU_ACCOUNTING jiffies_to_cputime(1) is not compile time constant and run time calculations are quite expensive. To optimize we use precomputed value. For all other architectures is is preprocessor definition. Signed-off-by:
-
Stanislaw Gruszka authored
Don't update values in expiration cache when new ones are equal. Add expire_le() and expire_gt() helpers to simplify the code. Signed-off-by:
-
Stanislaw Gruszka authored
Measure ITIMER_PROF and ITIMER_VIRT timers interval error between real ticks and requested by user. Take it into account when scheduling next tick. This patch introduce possibility where time between two consecutive tics is smaller then requested interval, it preserve however dependency that n tick is generated not earlier than n*interval time - counting from the beginning of periodic signal generation. Signed-off-by:
-
Stanislaw Gruszka authored
Both cpu itimers have same data flow in the few places, this patch make unification of code related with VIRT and PROF itimers. Signed-off-by:
-
- Apr 30, 2009
-
-
H Hartley Sweeten authored
Sparse reports the following in kernel/posix-cpu-timers.c: warning: symbol 'firing' shadows an earlier one Signed-off-by:
H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Subrata Modak <subrata@linux.vnet.ibm.com> LKML-Reference: <BD79186B4FD85F4B8E60E381CAEE1909016C1AFE@mi8nycmail19.Mi8.com> Signed-off-by:
-
- Apr 08, 2009
-
-
Oleg Nesterov authored
update_rlimit_cpu() tries to optimize out set_process_cpu_timer() in case when we already have CPUCLOCK_PROF timer which should expire first. But it uses cputime_lt() instead of cputime_gt(). Test case: int main(void) { struct itimerval it = { .it_value = { .tv_sec = 1000 }, }; assert(!setitimer(ITIMER_PROF, &it, NULL)); struct rlimit rl = { .rlim_cur = 1, .rlim_max = 1, }; assert(!setrlimit(RLIMIT_CPU, &rl)); for (;;) ; return 0; } Without this patch, the task is not killed as RLIMIT_CPU demands. Signed-off-by:
-
- Apr 01, 2009
-
-
Hidetoshi Seto authored
Impact: Regression fix (against clock_gettime() backwarding bug) This patch re-introduces a couple of functions, task_sched_runtime and thread_group_sched_runtime, which was once removed at the time of 2.6.28-rc1. These functions protect the sampling of thread/process clock with rq lock. This rq lock is required not to update rq->clock during the sampling. i.e. The clock_gettime() may return ((accounted runtime before update) + (delta after update)) that is less than what it should be. v2 -> v3: - Rename static helper function __task_delta_exec() to do_task_delta_exec() since -tip tree already has a __task_delta_exec() of different version. v1 -> v2: - Revises comments of function and patch description. - Add note about accuracy of thread group's runtime. Signed-off-by:
Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Acked-by:
-
- Mar 23, 2009
-
-
Oleg Nesterov authored
See http://bugzilla.kernel.org/show_bug.cgi?id=12911 copy_signal() copies signal->rlim, but RLIMIT_CPU is "lost". Because posix_cpu_timers_init_group() sets cputime_expires.prof_exp = 0 and thus fastpath_timer_check() returns false unless we have other cpu timers. This is the minimal fix for 2.6.29 (tested) and 2.6.28. The patch is not optimal, we need further cleanups here. With this patch update_rlimit_cpu() is not really needed, but I don't think it should be removed. The proper fix (I think) is: - set_process_cpu_timer() should just start the cputimer->running logic (it does), no need to change cputime_expires.xxx_exp - posix_cpu_timers_init_group() should set ->running when needed - fastpath_timer_check() can check ->running instead of task_cputime_zero(signal->cputime_expires) Reported-by:
Peter Lojkin <ia6432@inbox.ru> Signed-off-by:
-
- Feb 13, 2009
-
-
Peter Zijlstra authored
While reviewing the manpages, I noticed I'd missed some clock vs timer sites. Make sure that all timer functions call cpu_timer_sample_group() and not cpu_clock_sample_group(). This ensures that we enable the process wide timer in time, and therefore pay the O(n) thread group cost from the syscall. Not doing it here, will result in the first jiffy tick after setting the timer doing this, resulting in a very expensive tick (but only once) and a delay in actually starting the timer. Signed-off-by:
-
- Feb 11, 2009
-
-
Peter Zijlstra authored
The POSIX timer interface allows for absolute time expiry values through the TIMER_ABSTIME flag, therefore we have to synchronize the timer to the clock every time we start it. Signed-off-by:
-
Peter Zijlstra authored
To decrease the chance of a missed enable, always enable the timer when we sample it, we'll always disable it when we find that there are no active timers in the jiffy tick. This fixes a flood of warnings reported by Mike Galbraith. Reported-by:
Mike Galbraith <efault@gmx.de> Signed-off-by:
-
- Feb 05, 2009
-
-
Peter Zijlstra authored
Change the process wide cpu timers/clocks so that we: 1) don't mess up the kernel with too many threads, 2) don't have a per-cpu allocation for each process, 3) have no impact when not used. In order to accomplish this we're going to split it into two parts: - clocks; which can take all the time they want since they run from user context -- ie. sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID) - timers; which need constant time sampling but since they're explicity used, the user can pay the overhead. The clock readout will go back to a full sum of the thread group, while the timers will run of a global 'clock' that only runs when needed, so only programs that make use of the facility pay the price. Signed-off-by:
-
- Jan 07, 2009
-
-
Peter Zijlstra authored
Either we bounce once cacheline per cpu per tick, yielding n^2 bounces or we just bounce a single.. Also, using per-cpu allocations for the thread-groups complicates the per-cpu allocator in that its currently aimed to be a fixed sized allocator and the only possible extention to that would be vmap based, which is seriously constrained on 32 bit archs. So making the per-cpu memory requirement depend on the number of processes is an issue. Lastly, it didn't deal with cpu-hotplug, although admittedly that might be fixable. Signed-off-by:
-
