* [PATCH] sched/isolation: add a workqueue parameter to constrain unbound CPUs @ 2023-06-13 9:28 tiozhang 2023-06-14 9:19 ` [PATCH v2] " tiozhang 0 siblings, 1 reply; 7+ messages in thread From: tiozhang @ 2023-06-13 9:28 UTC (permalink / raw) To: mingo, peterz, juri.lelli, vincent.guittot, tj Cc: dietmar.eggemann, rostedt, bsegall, mgorman, bristot, vschneid, zyhtheonly, tiozhang, zwp10758, fuyuanli, zyhtheonly, linux-kernel Motivation of doing this is to better improve boot times for devices when we want to prevent our workqueue works from running on some specific CPUs, i,e, some CPUs are busy with interrupts. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: tiozhang <tiozhang@didiglobal.com> --- kernel/sched/isolation.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 373d42c707bc..85e744c1349a 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -208,6 +208,12 @@ static int __init housekeeping_isolcpus_setup(char *str) continue; } + if (!strncmp(str, "workqueue,", 10)) { + str += 10; + flags |= HK_FLAG_WQ; + continue; + } + if (!strncmp(str, "managed_irq,", 12)) { str += 12; flags |= HK_FLAG_MANAGED_IRQ; -- 2.17.1 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2] sched/isolation: add a workqueue parameter to constrain unbound CPUs 2023-06-13 9:28 [PATCH] sched/isolation: add a workqueue parameter to constrain unbound CPUs tiozhang @ 2023-06-14 9:19 ` tiozhang 2023-06-21 20:51 ` Tejun Heo 0 siblings, 1 reply; 7+ messages in thread From: tiozhang @ 2023-06-14 9:19 UTC (permalink / raw) To: tj, mingo, peterz, juri.lelli, vincent.guittot Cc: linux-kernel, dietmar.eggemann, rostedt, bsegall, mgorman, bristot, vschneid, fuyuanli, zwp10758, tiozhang, zyhtheonly, zyhtheonly Motivation of doing this is to better improve boot times for devices when we want to prevent our workqueue works from running on some specific CPUs, e,g, some CPUs are busy with interrupts. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: tiozhang <tiozhang@didiglobal.com> --- kernel/sched/isolation.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 373d42c707bc..5cd67c51622e 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -181,8 +181,8 @@ static int __init housekeeping_nohz_full_setup(char *str) { unsigned long flags; - flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | - HK_FLAG_MISC | HK_FLAG_KTHREAD; + flags = HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC + | HK_FLAG_KTHREAD; return housekeeping_setup(str, flags); } @@ -208,6 +208,12 @@ static int __init housekeeping_isolcpus_setup(char *str) continue; } + if (!strncmp(str, "workqueue,", 10)) { + str += 10; + flags |= HK_FLAG_WQ; + continue; + } + if (!strncmp(str, "managed_irq,", 12)) { str += 12; flags |= HK_FLAG_MANAGED_IRQ; -- 2.17.1 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2] sched/isolation: add a workqueue parameter to constrain unbound CPUs 2023-06-14 9:19 ` [PATCH v2] " tiozhang @ 2023-06-21 20:51 ` Tejun Heo 2023-06-22 3:22 ` [PATCH v3] sched/isolation: add a workqueue parameter onto isolcpus " tiozhang 2023-06-22 3:47 ` [PATCH v2] sched/isolation: add a workqueue parameter " Yuanhan Zhang 0 siblings, 2 replies; 7+ messages in thread From: Tejun Heo @ 2023-06-21 20:51 UTC (permalink / raw) To: mingo, peterz, juri.lelli, vincent.guittot, linux-kernel, dietmar.eggemann, rostedt, bsegall, mgorman, bristot, vschneid, fuyuanli, zwp10758, zyhtheonly, zyhtheonly On Wed, Jun 14, 2023 at 05:19:45PM +0800, tiozhang wrote: ... > @@ -181,8 +181,8 @@ static int __init housekeeping_nohz_full_setup(char *str) > { > unsigned long flags; > > - flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | > - HK_FLAG_MISC | HK_FLAG_KTHREAD; > + flags = HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC > + | HK_FLAG_KTHREAD; Why is WQ being taken out of nohz_full setup? The patch description doesn't mention anything. > @@ -208,6 +208,12 @@ static int __init housekeeping_isolcpus_setup(char *str) > continue; > } > > + if (!strncmp(str, "workqueue,", 10)) { > + str += 10; > + flags |= HK_FLAG_WQ; > + continue; > + } I wonder whether it'd be better to just add a workqueue boot param but if this works it's fine too. Thanks. -- tejun ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v3] sched/isolation: add a workqueue parameter onto isolcpus to constrain unbound CPUs 2023-06-21 20:51 ` Tejun Heo @ 2023-06-22 3:22 ` tiozhang 2023-06-26 20:54 ` Tejun Heo 2023-06-26 22:59 ` Frederic Weisbecker 2023-06-22 3:47 ` [PATCH v2] sched/isolation: add a workqueue parameter " Yuanhan Zhang 1 sibling, 2 replies; 7+ messages in thread From: tiozhang @ 2023-06-22 3:22 UTC (permalink / raw) To: tj, mingo, peterz, juri.lelli, vincent.guittot Cc: linux-kernel, dietmar.eggemann, rostedt, bsegall, mgorman, bristot, vschneid, fuyuanli, zwp10758, zyhtheonly, zyhtheonly, tiozhang Motivation of doing this is to better improve boot times for devices when we want to prevent our workqueue works from running on some specific CPUs, i,e, some CPUs are busy with interrupts. Also remove HK_FLAG_WQ from nohz_full to prevent nohz_full overriding workqueue's cpu config. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: tiozhang <tiozhang@didiglobal.com> --- kernel/sched/isolation.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 373d42c707bc..5cd67c51622e 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -181,8 +181,8 @@ static int __init housekeeping_nohz_full_setup(char *str) { unsigned long flags; - flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | - HK_FLAG_MISC | HK_FLAG_KTHREAD; + flags = HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC + | HK_FLAG_KTHREAD; return housekeeping_setup(str, flags); } @@ -208,6 +208,12 @@ static int __init housekeeping_isolcpus_setup(char *str) continue; } + if (!strncmp(str, "workqueue,", 10)) { + str += 10; + flags |= HK_FLAG_WQ; + continue; + } + if (!strncmp(str, "managed_irq,", 12)) { str += 12; flags |= HK_FLAG_MANAGED_IRQ; -- 2.17.1 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v3] sched/isolation: add a workqueue parameter onto isolcpus to constrain unbound CPUs 2023-06-22 3:22 ` [PATCH v3] sched/isolation: add a workqueue parameter onto isolcpus " tiozhang @ 2023-06-26 20:54 ` Tejun Heo 2023-06-26 22:59 ` Frederic Weisbecker 1 sibling, 0 replies; 7+ messages in thread From: Tejun Heo @ 2023-06-26 20:54 UTC (permalink / raw) To: mingo, peterz, juri.lelli, vincent.guittot, linux-kernel, dietmar.eggemann, rostedt, bsegall, mgorman, bristot, vschneid, fuyuanli, zwp10758, zyhtheonly, zyhtheonly On Thu, Jun 22, 2023 at 11:22:17AM +0800, tiozhang wrote: > Motivation of doing this is to better improve boot times for devices when > we want to prevent our workqueue works from running on some specific CPUs, > i,e, some CPUs are busy with interrupts. > > Also remove HK_FLAG_WQ from nohz_full to prevent nohz_full overriding > workqueue's cpu config. > > Suggested-by: Tejun Heo <tj@kernel.org> > Signed-off-by: tiozhang <tiozhang@didiglobal.com> Let's just do the workqueue specific parameter. I'll apply the other one to the workqueue branch after the merge window. Thanks. -- tejun ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3] sched/isolation: add a workqueue parameter onto isolcpus to constrain unbound CPUs 2023-06-22 3:22 ` [PATCH v3] sched/isolation: add a workqueue parameter onto isolcpus " tiozhang 2023-06-26 20:54 ` Tejun Heo @ 2023-06-26 22:59 ` Frederic Weisbecker 1 sibling, 0 replies; 7+ messages in thread From: Frederic Weisbecker @ 2023-06-26 22:59 UTC (permalink / raw) To: tj, mingo, peterz, juri.lelli, vincent.guittot, linux-kernel, dietmar.eggemann, rostedt, bsegall, mgorman, bristot, vschneid, fuyuanli, zwp10758, zyhtheonly, zyhtheonly On Thu, Jun 22, 2023 at 11:22:17AM +0800, tiozhang wrote: > Motivation of doing this is to better improve boot times for devices when > we want to prevent our workqueue works from running on some specific CPUs, > i,e, some CPUs are busy with interrupts. > > Also remove HK_FLAG_WQ from nohz_full to prevent nohz_full overriding > workqueue's cpu config. But then nohz_full= doesn't re-affine workqueues anymore, right? > > Suggested-by: Tejun Heo <tj@kernel.org> > Signed-off-by: tiozhang <tiozhang@didiglobal.com> > --- > kernel/sched/isolation.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c > index 373d42c707bc..5cd67c51622e 100644 > --- a/kernel/sched/isolation.c > +++ b/kernel/sched/isolation.c > @@ -181,8 +181,8 @@ static int __init housekeeping_nohz_full_setup(char *str) > { > unsigned long flags; > > - flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | > - HK_FLAG_MISC | HK_FLAG_KTHREAD; > + flags = HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC > + | HK_FLAG_KTHREAD; > > return housekeeping_setup(str, flags); > } > @@ -208,6 +208,12 @@ static int __init housekeeping_isolcpus_setup(char *str) > continue; > } > > + if (!strncmp(str, "workqueue,", 10)) { > + str += 10; > + flags |= HK_FLAG_WQ; > + continue; > + } > + I'm planning on removing HK_FLAG_TICK, HK_FLAG_WQ, HK_FLAG_TIMER, HK_FLAG_RCU, HK_FLAG_MISC and HK_FLAG_KTHREAD and merge them all together. Also the problem with these flags is that once they are modified on boot, you can't modify them later. I much prefer what was done in this patch: https://lore.kernel.org/all/20230623073033.GA6584@didi-ThinkCentre-M930t-N000/ Thanks! > if (!strncmp(str, "managed_irq,", 12)) { > str += 12; > flags |= HK_FLAG_MANAGED_IRQ; > -- > 2.17.1 > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] sched/isolation: add a workqueue parameter to constrain unbound CPUs 2023-06-21 20:51 ` Tejun Heo 2023-06-22 3:22 ` [PATCH v3] sched/isolation: add a workqueue parameter onto isolcpus " tiozhang @ 2023-06-22 3:47 ` Yuanhan Zhang 1 sibling, 0 replies; 7+ messages in thread From: Yuanhan Zhang @ 2023-06-22 3:47 UTC (permalink / raw) To: Tejun Heo Cc: mingo, peterz, juri.lelli, vincent.guittot, linux-kernel, dietmar.eggemann, rostedt, bsegall, mgorman, bristot, vschneid, fuyuanli, zwp10758, zyhtheonly Tejun Heo <tj@kernel.org> 于2023年6月22日周四 04:51写道： > > On Wed, Jun 14, 2023 at 05:19:45PM +0800, tiozhang wrote: > ... > > @@ -181,8 +181,8 @@ static int __init housekeeping_nohz_full_setup(char *str) > > { > > unsigned long flags; > > > > - flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | > > - HK_FLAG_MISC | HK_FLAG_KTHREAD; > > + flags = HK_FLAG_TICK | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC > > + | HK_FLAG_KTHREAD; > > Why is WQ being taken out of nohz_full setup? The patch description doesn't > mention anything. To prevent nohz_full from rewriting workqueue's choice. Add a description in patch v3. > > > @@ -208,6 +208,12 @@ static int __init housekeeping_isolcpus_setup(char *str) > > continue; > > } > > > > + if (!strncmp(str, "workqueue,", 10)) { > > + str += 10; > > + flags |= HK_FLAG_WQ; > > + continue; > > + } > > I wonder whether it'd be better to just add a workqueue boot param but if I also write a patch this way, please see '[PATCH] workqueue: add cmdline parameter `unbound_workqueue_cpus` to further constrain wq_unbound_cpumask at boot time'. If you think it is better I'm happy to continue on this :) > this works it's fine too. It works since we use this cpumask to constrain wq_unbound_cpumask in workqueue's early init. > > Thanks. > > -- > tejun Thank you, tiozhang ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2023-06-26 22:59 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-06-13 9:28 [PATCH] sched/isolation: add a workqueue parameter to constrain unbound CPUs tiozhang 2023-06-14 9:19 ` [PATCH v2] " tiozhang 2023-06-21 20:51 ` Tejun Heo 2023-06-22 3:22 ` [PATCH v3] sched/isolation: add a workqueue parameter onto isolcpus " tiozhang 2023-06-26 20:54 ` Tejun Heo 2023-06-26 22:59 ` Frederic Weisbecker 2023-06-22 3:47 ` [PATCH v2] sched/isolation: add a workqueue parameter " Yuanhan Zhang
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