* [PATCH -tip 0/2] kernel/hrtimer: Ignore slack time for RT tasks @ 2023-01-23 17:32 Davidlohr Bueso 2023-01-23 17:32 ` [PATCH 1/2] kernel/hrtimer: Rely on rt_task() for DL tasks too Davidlohr Bueso 2023-01-23 17:32 ` [PATCH 2/2] kernel/hrtimer: Ignore slack time for RT tasks Davidlohr Bueso 0 siblings, 2 replies; 6+ messages in thread From: Davidlohr Bueso @ 2023-01-23 17:32 UTC (permalink / raw) To: tglx; +Cc: mingo, peterz, bigeasy, dave, linux-rt-users, linux-kernel Hi, Patch 2 simply ignores any user passed slack time in the case of RT/DL tasks for schedule_hrtimeout_range, which is aligned to what nanosleep(2) already does. Thanks! Davidlohr Bueso (2): kernel/hrtimer: Rely on rt_task() for DL tasks too kernel/hrtimer: Ignore slack time for RT tasks kernel/time/hrtimer.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) -- 2.39.0 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/2] kernel/hrtimer: Rely on rt_task() for DL tasks too 2023-01-23 17:32 [PATCH -tip 0/2] kernel/hrtimer: Ignore slack time for RT tasks Davidlohr Bueso @ 2023-01-23 17:32 ` Davidlohr Bueso 2023-01-31 10:24 ` Thomas Gleixner 2023-01-31 10:29 ` [tip: timers/core] hrtimer: " tip-bot2 for Davidlohr Bueso 2023-01-23 17:32 ` [PATCH 2/2] kernel/hrtimer: Ignore slack time for RT tasks Davidlohr Bueso 1 sibling, 2 replies; 6+ messages in thread From: Davidlohr Bueso @ 2023-01-23 17:32 UTC (permalink / raw) To: tglx; +Cc: mingo, peterz, bigeasy, dave, linux-rt-users, linux-kernel Having dl_task() is redundant, trivially simplify. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> --- kernel/time/hrtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 3ae661ab6260..8336c2618ec1 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2089,7 +2089,7 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode, u64 slack; slack = current->timer_slack_ns; - if (dl_task(current) || rt_task(current)) + if (rt_task(current)) slack = 0; hrtimer_init_sleeper_on_stack(&t, clockid, mode); -- 2.39.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] kernel/hrtimer: Rely on rt_task() for DL tasks too 2023-01-23 17:32 ` [PATCH 1/2] kernel/hrtimer: Rely on rt_task() for DL tasks too Davidlohr Bueso @ 2023-01-31 10:24 ` Thomas Gleixner 2023-01-31 10:29 ` [tip: timers/core] hrtimer: " tip-bot2 for Davidlohr Bueso 1 sibling, 0 replies; 6+ messages in thread From: Thomas Gleixner @ 2023-01-31 10:24 UTC (permalink / raw) To: Davidlohr Bueso Cc: mingo, peterz, bigeasy, dave, linux-rt-users, linux-kernel On Mon, Jan 23 2023 at 09:32, Davidlohr Bueso wrote: 'kernel/hrtimer:' is not the correct prefix. Hint: git log --oneline path/to/file I fixed that up for you this time.... ^ permalink raw reply [flat|nested] 6+ messages in thread
* [tip: timers/core] hrtimer: Rely on rt_task() for DL tasks too 2023-01-23 17:32 ` [PATCH 1/2] kernel/hrtimer: Rely on rt_task() for DL tasks too Davidlohr Bueso 2023-01-31 10:24 ` Thomas Gleixner @ 2023-01-31 10:29 ` tip-bot2 for Davidlohr Bueso 1 sibling, 0 replies; 6+ messages in thread From: tip-bot2 for Davidlohr Bueso @ 2023-01-31 10:29 UTC (permalink / raw) To: linux-tip-commits; +Cc: Davidlohr Bueso, Thomas Gleixner, x86, linux-kernel The following commit has been merged into the timers/core branch of tip: Commit-ID: c14fd3dcacaa480394d3ac0b4a91a7d17a4b5516 Gitweb: https://git.kernel.org/tip/c14fd3dcacaa480394d3ac0b4a91a7d17a4b5516 Author: Davidlohr Bueso <dave@stgolabs.net> AuthorDate: Mon, 23 Jan 2023 09:32:05 -08:00 Committer: Thomas Gleixner <tglx@linutronix.de> CommitterDate: Tue, 31 Jan 2023 11:23:07 +01:00 hrtimer: Rely on rt_task() for DL tasks too Checking dl_task() is redundant as rt_task() returns true for deadline tasks too. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230123173206.6764-2-dave@stgolabs.net --- kernel/time/hrtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index e4f0e3b..667b713 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2089,7 +2089,7 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode, u64 slack; slack = current->timer_slack_ns; - if (dl_task(current) || rt_task(current)) + if (rt_task(current)) slack = 0; hrtimer_init_sleeper_on_stack(&t, clockid, mode); ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] kernel/hrtimer: Ignore slack time for RT tasks 2023-01-23 17:32 [PATCH -tip 0/2] kernel/hrtimer: Ignore slack time for RT tasks Davidlohr Bueso 2023-01-23 17:32 ` [PATCH 1/2] kernel/hrtimer: Rely on rt_task() for DL tasks too Davidlohr Bueso @ 2023-01-23 17:32 ` Davidlohr Bueso 2023-01-31 10:29 ` [tip: timers/core] hrtimer: Ignore slack time for RT tasks in schedule_hrtimeout_range() tip-bot2 for Davidlohr Bueso 1 sibling, 1 reply; 6+ messages in thread From: Davidlohr Bueso @ 2023-01-23 17:32 UTC (permalink / raw) To: tglx; +Cc: mingo, peterz, bigeasy, dave, linux-rt-users, linux-kernel While in theory the timer can be triggered before expires+delta, for the cases of RT tasks they really have no business giving any lenience for extra slack time, so override any passed value by the user and always use zero for schedule_hrtimeout_range() calls. Furthermore, this is similar to what the nanosleep(2) family already does with current->timer_slack_ns. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> --- kernel/time/hrtimer.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 8336c2618ec1..78f2e07d3e7d 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2270,7 +2270,7 @@ void __init hrtimers_init(void) /** * schedule_hrtimeout_range_clock - sleep until timeout * @expires: timeout value (ktime_t) - * @delta: slack in expires timeout (ktime_t) + * @delta: slack in expires timeout (ktime_t) for SCHED_OTHER tasks * @mode: timer mode * @clock_id: timer clock to be used */ @@ -2297,6 +2297,13 @@ schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta, return -EINTR; } + /* + * Override any slack passed by the user if under + * rt contraints. + */ + if (rt_task(current)) + delta = 0; + hrtimer_init_sleeper_on_stack(&t, clock_id, mode); hrtimer_set_expires_range_ns(&t.timer, *expires, delta); hrtimer_sleeper_start_expires(&t, mode); @@ -2316,7 +2323,7 @@ EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock); /** * schedule_hrtimeout_range - sleep until timeout * @expires: timeout value (ktime_t) - * @delta: slack in expires timeout (ktime_t) + * @delta: slack in expires timeout (ktime_t) for SCHED_OTHER tasks * @mode: timer mode * * Make the current task sleep until the given expiry time has @@ -2324,7 +2331,8 @@ EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock); * the current task state has been set (see set_current_state()). * * The @delta argument gives the kernel the freedom to schedule the - * actual wakeup to a time that is both power and performance friendly. + * actual wakeup to a time that is both power and performance friendly + * for regular (non RT/DL) tasks. * The kernel give the normal best effort behavior for "@expires+@delta", * but may decide to fire the timer earlier, but no earlier than @expires. * -- 2.39.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [tip: timers/core] hrtimer: Ignore slack time for RT tasks in schedule_hrtimeout_range() 2023-01-23 17:32 ` [PATCH 2/2] kernel/hrtimer: Ignore slack time for RT tasks Davidlohr Bueso @ 2023-01-31 10:29 ` tip-bot2 for Davidlohr Bueso 0 siblings, 0 replies; 6+ messages in thread From: tip-bot2 for Davidlohr Bueso @ 2023-01-31 10:29 UTC (permalink / raw) To: linux-tip-commits; +Cc: Davidlohr Bueso, Thomas Gleixner, x86, linux-kernel The following commit has been merged into the timers/core branch of tip: Commit-ID: 0c52310f260014d95c1310364379772cb74cf82d Gitweb: https://git.kernel.org/tip/0c52310f260014d95c1310364379772cb74cf82d Author: Davidlohr Bueso <dave@stgolabs.net> AuthorDate: Mon, 23 Jan 2023 09:32:06 -08:00 Committer: Thomas Gleixner <tglx@linutronix.de> CommitterDate: Tue, 31 Jan 2023 11:23:07 +01:00 hrtimer: Ignore slack time for RT tasks in schedule_hrtimeout_range() While in theory the timer can be triggered before expires + delta, for the cases of RT tasks they really have no business giving any lenience for extra slack time, so override any passed value by the user and always use zero for schedule_hrtimeout_range() calls. Furthermore, this is similar to what the nanosleep(2) family already does with current->timer_slack_ns. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230123173206.6764-3-dave@stgolabs.net --- kernel/time/hrtimer.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 667b713..e8c0829 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2272,7 +2272,7 @@ void __init hrtimers_init(void) /** * schedule_hrtimeout_range_clock - sleep until timeout * @expires: timeout value (ktime_t) - * @delta: slack in expires timeout (ktime_t) + * @delta: slack in expires timeout (ktime_t) for SCHED_OTHER tasks * @mode: timer mode * @clock_id: timer clock to be used */ @@ -2299,6 +2299,13 @@ schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta, return -EINTR; } + /* + * Override any slack passed by the user if under + * rt contraints. + */ + if (rt_task(current)) + delta = 0; + hrtimer_init_sleeper_on_stack(&t, clock_id, mode); hrtimer_set_expires_range_ns(&t.timer, *expires, delta); hrtimer_sleeper_start_expires(&t, mode); @@ -2318,7 +2325,7 @@ EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock); /** * schedule_hrtimeout_range - sleep until timeout * @expires: timeout value (ktime_t) - * @delta: slack in expires timeout (ktime_t) + * @delta: slack in expires timeout (ktime_t) for SCHED_OTHER tasks * @mode: timer mode * * Make the current task sleep until the given expiry time has @@ -2326,7 +2333,8 @@ EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock); * the current task state has been set (see set_current_state()). * * The @delta argument gives the kernel the freedom to schedule the - * actual wakeup to a time that is both power and performance friendly. + * actual wakeup to a time that is both power and performance friendly + * for regular (non RT/DL) tasks. * The kernel give the normal best effort behavior for "@expires+@delta", * but may decide to fire the timer earlier, but no earlier than @expires. * ^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-01-31 10:29 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2023-01-23 17:32 [PATCH -tip 0/2] kernel/hrtimer: Ignore slack time for RT tasks Davidlohr Bueso 2023-01-23 17:32 ` [PATCH 1/2] kernel/hrtimer: Rely on rt_task() for DL tasks too Davidlohr Bueso 2023-01-31 10:24 ` Thomas Gleixner 2023-01-31 10:29 ` [tip: timers/core] hrtimer: " tip-bot2 for Davidlohr Bueso 2023-01-23 17:32 ` [PATCH 2/2] kernel/hrtimer: Ignore slack time for RT tasks Davidlohr Bueso 2023-01-31 10:29 ` [tip: timers/core] hrtimer: Ignore slack time for RT tasks in schedule_hrtimeout_range() tip-bot2 for Davidlohr Bueso
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