Peter?
-- Steve On Tue, 8 Dec 2020 07:58:54 +0000 Tianxianting <[email protected]> wrote: > Thanks, > We met an issue that a normal thread can't get cpu, > And at this moment, we found 'sched: RT throttling activated' log. > > So I think this patch is useful for such issue. > > Could I get more comments? Thanks in advance > -----Original Message----- > From: Steven Rostedt [mailto:[email protected]] > Sent: Thursday, December 03, 2020 10:40 PM > To: tianxianting (RD) <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected] > Subject: Re: [PATCH] sched/rt: Print curr when RT throttling activated > > On Thu, 3 Dec 2020 15:51:29 +0800 > Xianting Tian <[email protected]> wrote: > > > We may meet the issue, that one RT thread occupied the cpu by > > 950ms/1s, The RT thread maybe is a business thread or other unknown thread. > > > > Currently, it only outputs the print "sched: RT throttling activated" > > when RT throttling happen. It is hard to know what is the RT thread, > > For further analysis, we need add more prints. > > > > This patch is to print current RT task when RT throttling activated, > > It help us to know what is the RT thread in the first time. > > I think this can be useful information to include. > > Acked-by: Steven Rostedt (VMware) <[email protected]> > > -- Steve > > > > > Signed-off-by: Xianting Tian <[email protected]> > > --- > > kernel/sched/rt.c | 7 ++++--- > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index > > f215eea6a..8913f38cb 100644 > > --- a/kernel/sched/rt.c > > +++ b/kernel/sched/rt.c > > @@ -946,7 +946,7 @@ static inline int rt_se_prio(struct sched_rt_entity > > *rt_se) > > return rt_task_of(rt_se)->prio; > > } > > > > -static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) > > +static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq, struct > > +task_struct *curr) > > { > > u64 runtime = sched_rt_runtime(rt_rq); > > > > @@ -970,7 +970,8 @@ static int sched_rt_runtime_exceeded(struct rt_rq > > *rt_rq) > > */ > > if (likely(rt_b->rt_runtime)) { > > rt_rq->rt_throttled = 1; > > - printk_deferred_once("sched: RT throttling > > activated\n"); > > + printk_deferred_once("sched: RT throttling activated > > (curr: pid %d, comm %s)\n", > > + curr->pid, curr->comm); > > } else { > > /* > > * In case we did anyway, make it go away, @@ -1026,7 > > +1027,7 @@ > > static void update_curr_rt(struct rq *rq) > > if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { > > raw_spin_lock(&rt_rq->rt_runtime_lock); > > rt_rq->rt_time += delta_exec; > > - if (sched_rt_runtime_exceeded(rt_rq)) > > + if (sched_rt_runtime_exceeded(rt_rq, curr)) > > resched_curr(rq); > > raw_spin_unlock(&rt_rq->rt_runtime_lock); > > }
