Re: INFO: rcu detected stall in do_idle

2018-11-07 Thread Daniel Bristot de Oliveira
On 11/5/18 11:55 AM, Juri Lelli wrote: > On 02/11/18 11:00, Daniel Bristot de Oliveira wrote: >> On 11/1/18 6:55 AM, Juri Lelli wrote: I meant, I am not against the/a fix, i just think that... it is more complicated that it seems. For example: Let's assume that we have a

Re: INFO: rcu detected stall in do_idle

2018-11-07 Thread Daniel Bristot de Oliveira
On 11/5/18 11:55 AM, Juri Lelli wrote: > On 02/11/18 11:00, Daniel Bristot de Oliveira wrote: >> On 11/1/18 6:55 AM, Juri Lelli wrote: I meant, I am not against the/a fix, i just think that... it is more complicated that it seems. For example: Let's assume that we have a

Re: INFO: rcu detected stall in do_idle

2018-11-06 Thread Juri Lelli
On 30/10/18 12:12, Juri Lelli wrote: > On 30/10/18 11:45, Peter Zijlstra wrote: > > [...] > > > Hurm.. right. We knew of this issue back when we did it. > > I suppose now it hurts and we need to figure something out. > > > > By virtue of being a real-time class, we do indeed need to have

Re: INFO: rcu detected stall in do_idle

2018-11-06 Thread Juri Lelli
On 30/10/18 12:12, Juri Lelli wrote: > On 30/10/18 11:45, Peter Zijlstra wrote: > > [...] > > > Hurm.. right. We knew of this issue back when we did it. > > I suppose now it hurts and we need to figure something out. > > > > By virtue of being a real-time class, we do indeed need to have

Re: INFO: rcu detected stall in do_idle

2018-11-05 Thread Juri Lelli
On 02/11/18 11:00, Daniel Bristot de Oliveira wrote: > On 11/1/18 6:55 AM, Juri Lelli wrote: > >> I meant, I am not against the/a fix, i just think that... it is more > >> complicated > >> that it seems. > >> > >> For example: Let's assume that we have a non-rt bad thread A in CPU 0 > >>

Re: INFO: rcu detected stall in do_idle

2018-11-05 Thread Juri Lelli
On 02/11/18 11:00, Daniel Bristot de Oliveira wrote: > On 11/1/18 6:55 AM, Juri Lelli wrote: > >> I meant, I am not against the/a fix, i just think that... it is more > >> complicated > >> that it seems. > >> > >> For example: Let's assume that we have a non-rt bad thread A in CPU 0 > >>

Re: INFO: rcu detected stall in do_idle

2018-11-02 Thread Daniel Bristot de Oliveira
On 11/1/18 6:55 AM, Juri Lelli wrote: >> I meant, I am not against the/a fix, i just think that... it is more >> complicated >> that it seems. >> >> For example: Let's assume that we have a non-rt bad thread A in CPU 0 >> generating >> IPIs because of static key update, and a good dl thread B in

Re: INFO: rcu detected stall in do_idle

2018-11-02 Thread Daniel Bristot de Oliveira
On 11/1/18 6:55 AM, Juri Lelli wrote: >> I meant, I am not against the/a fix, i just think that... it is more >> complicated >> that it seems. >> >> For example: Let's assume that we have a non-rt bad thread A in CPU 0 >> generating >> IPIs because of static key update, and a good dl thread B in

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Juri Lelli
On 31/10/18 18:58, Daniel Bristot de Oliveira wrote: > On 10/31/18 5:40 PM, Juri Lelli wrote: > > On 31/10/18 17:18, Daniel Bristot de Oliveira wrote: > >> On 10/30/18 12:08 PM, luca abeni wrote: > >>> Hi Peter, > >>> > >>> On Tue, 30 Oct 2018 11:45:54 +0100 > >>> Peter Zijlstra wrote: > >>>

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Juri Lelli
On 31/10/18 18:58, Daniel Bristot de Oliveira wrote: > On 10/31/18 5:40 PM, Juri Lelli wrote: > > On 31/10/18 17:18, Daniel Bristot de Oliveira wrote: > >> On 10/30/18 12:08 PM, luca abeni wrote: > >>> Hi Peter, > >>> > >>> On Tue, 30 Oct 2018 11:45:54 +0100 > >>> Peter Zijlstra wrote: > >>>

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Daniel Bristot de Oliveira
On 10/31/18 5:40 PM, Juri Lelli wrote: > On 31/10/18 17:18, Daniel Bristot de Oliveira wrote: >> On 10/30/18 12:08 PM, luca abeni wrote: >>> Hi Peter, >>> >>> On Tue, 30 Oct 2018 11:45:54 +0100 >>> Peter Zijlstra wrote: >>> [...] > 2. This is related to perf_event_open syscall reproducer

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Daniel Bristot de Oliveira
On 10/31/18 5:40 PM, Juri Lelli wrote: > On 31/10/18 17:18, Daniel Bristot de Oliveira wrote: >> On 10/30/18 12:08 PM, luca abeni wrote: >>> Hi Peter, >>> >>> On Tue, 30 Oct 2018 11:45:54 +0100 >>> Peter Zijlstra wrote: >>> [...] > 2. This is related to perf_event_open syscall reproducer

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Peter Zijlstra
On Wed, Oct 31, 2018 at 05:40:10PM +0100, Juri Lelli wrote: > I'm seeing something along the lines of what Peter suggested as a last > resort measure we probably still need to put in place. Yes, you certainly hope to never hit that, and should not in a proper setup. But we need something to keep

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Peter Zijlstra
On Wed, Oct 31, 2018 at 05:40:10PM +0100, Juri Lelli wrote: > I'm seeing something along the lines of what Peter suggested as a last > resort measure we probably still need to put in place. Yes, you certainly hope to never hit that, and should not in a proper setup. But we need something to keep

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Peter Zijlstra
On Wed, Oct 31, 2018 at 05:18:00PM +0100, Daniel Bristot de Oliveira wrote: > Brazilian part of the Ph.D we are dealing with probabilistic worst case > execution time, and to be able to use probabilistic methods, we need to remove > the noise of the IRQs in the execution time [1]. So, IMHO, using

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Peter Zijlstra
On Wed, Oct 31, 2018 at 05:18:00PM +0100, Daniel Bristot de Oliveira wrote: > Brazilian part of the Ph.D we are dealing with probabilistic worst case > execution time, and to be able to use probabilistic methods, we need to remove > the noise of the IRQs in the execution time [1]. So, IMHO, using

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Juri Lelli
On 31/10/18 17:18, Daniel Bristot de Oliveira wrote: > On 10/30/18 12:08 PM, luca abeni wrote: > > Hi Peter, > > > > On Tue, 30 Oct 2018 11:45:54 +0100 > > Peter Zijlstra wrote: > > [...] > >>> 2. This is related to perf_event_open syscall reproducer does > >>> before becoming DEADLINE and

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Juri Lelli
On 31/10/18 17:18, Daniel Bristot de Oliveira wrote: > On 10/30/18 12:08 PM, luca abeni wrote: > > Hi Peter, > > > > On Tue, 30 Oct 2018 11:45:54 +0100 > > Peter Zijlstra wrote: > > [...] > >>> 2. This is related to perf_event_open syscall reproducer does > >>> before becoming DEADLINE and

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Daniel Bristot de Oliveira
On 10/30/18 12:08 PM, luca abeni wrote: > Hi Peter, > > On Tue, 30 Oct 2018 11:45:54 +0100 > Peter Zijlstra wrote: > [...] >>> 2. This is related to perf_event_open syscall reproducer does >>> before becoming DEADLINE and entering the busy loop. Enabling of >>> perf swevents generates lot of

Re: INFO: rcu detected stall in do_idle

2018-10-31 Thread Daniel Bristot de Oliveira
On 10/30/18 12:08 PM, luca abeni wrote: > Hi Peter, > > On Tue, 30 Oct 2018 11:45:54 +0100 > Peter Zijlstra wrote: > [...] >>> 2. This is related to perf_event_open syscall reproducer does >>> before becoming DEADLINE and entering the busy loop. Enabling of >>> perf swevents generates lot of

Re: INFO: rcu detected stall in do_idle

2018-10-30 Thread Juri Lelli
On 30/10/18 11:45, Peter Zijlstra wrote: [...] > Hurm.. right. We knew of this issue back when we did it. > I suppose now it hurts and we need to figure something out. > > By virtue of being a real-time class, we do indeed need to have deadline > on the wall-clock. But if we then don't account

Re: INFO: rcu detected stall in do_idle

2018-10-30 Thread Juri Lelli
On 30/10/18 11:45, Peter Zijlstra wrote: [...] > Hurm.. right. We knew of this issue back when we did it. > I suppose now it hurts and we need to figure something out. > > By virtue of being a real-time class, we do indeed need to have deadline > on the wall-clock. But if we then don't account

Re: INFO: rcu detected stall in do_idle

2018-10-30 Thread luca abeni
Hi Peter, On Tue, 30 Oct 2018 11:45:54 +0100 Peter Zijlstra wrote: [...] > > 2. This is related to perf_event_open syscall reproducer does > > before becoming DEADLINE and entering the busy loop. Enabling of > > perf swevents generates lot of hrtimers load that happens in the > > reproducer

Re: INFO: rcu detected stall in do_idle

2018-10-30 Thread luca abeni
Hi Peter, On Tue, 30 Oct 2018 11:45:54 +0100 Peter Zijlstra wrote: [...] > > 2. This is related to perf_event_open syscall reproducer does > > before becoming DEADLINE and entering the busy loop. Enabling of > > perf swevents generates lot of hrtimers load that happens in the > > reproducer

Re: INFO: rcu detected stall in do_idle

2018-10-30 Thread Peter Zijlstra
On Wed, Oct 24, 2018 at 02:03:35PM +0200, Juri Lelli wrote: > Pain points: > > 1. Granularity of enforcement (at each tick) is huge compared with > the task runtime. This makes starting the replenishment timer, > when runtime is depleted, always to fail (because old deadline > is way

Re: INFO: rcu detected stall in do_idle

2018-10-30 Thread Peter Zijlstra
On Wed, Oct 24, 2018 at 02:03:35PM +0200, Juri Lelli wrote: > Pain points: > > 1. Granularity of enforcement (at each tick) is huge compared with > the task runtime. This makes starting the replenishment timer, > when runtime is depleted, always to fail (because old deadline > is way

Re: INFO: rcu detected stall in do_idle

2018-10-28 Thread Juri Lelli
On 27/10/18 12:16, Dmitry Vyukov wrote: > On Wed, Oct 24, 2018 at 1:03 PM, Juri Lelli wrote: > > > > On 19/10/18 22:50, luca abeni wrote: > > > On Fri, 19 Oct 2018 13:39:42 +0200 > > > Peter Zijlstra wrote: > > > > > > > On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > > > > > Ok, I

Re: INFO: rcu detected stall in do_idle

2018-10-28 Thread Juri Lelli
On 27/10/18 12:16, Dmitry Vyukov wrote: > On Wed, Oct 24, 2018 at 1:03 PM, Juri Lelli wrote: > > > > On 19/10/18 22:50, luca abeni wrote: > > > On Fri, 19 Oct 2018 13:39:42 +0200 > > > Peter Zijlstra wrote: > > > > > > > On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > > > > > Ok, I

Re: INFO: rcu detected stall in do_idle

2018-10-27 Thread Dmitry Vyukov
On Wed, Oct 24, 2018 at 1:03 PM, Juri Lelli wrote: > > On 19/10/18 22:50, luca abeni wrote: > > On Fri, 19 Oct 2018 13:39:42 +0200 > > Peter Zijlstra wrote: > > > > > On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > > > > Ok, I see the issue now: the problem is that the "while > > >

Re: INFO: rcu detected stall in do_idle

2018-10-27 Thread Dmitry Vyukov
On Wed, Oct 24, 2018 at 1:03 PM, Juri Lelli wrote: > > On 19/10/18 22:50, luca abeni wrote: > > On Fri, 19 Oct 2018 13:39:42 +0200 > > Peter Zijlstra wrote: > > > > > On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > > > > Ok, I see the issue now: the problem is that the "while > > >

Re: INFO: rcu detected stall in do_idle

2018-10-24 Thread Juri Lelli
On 19/10/18 22:50, luca abeni wrote: > On Fri, 19 Oct 2018 13:39:42 +0200 > Peter Zijlstra wrote: > > > On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > > > Ok, I see the issue now: the problem is that the "while > > > (dl_se->runtime <= 0)" loop is executed at replenishment time,

Re: INFO: rcu detected stall in do_idle

2018-10-24 Thread Juri Lelli
On 19/10/18 22:50, luca abeni wrote: > On Fri, 19 Oct 2018 13:39:42 +0200 > Peter Zijlstra wrote: > > > On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > > > Ok, I see the issue now: the problem is that the "while > > > (dl_se->runtime <= 0)" loop is executed at replenishment time,

Re: INFO: rcu detected stall in do_idle

2018-10-19 Thread luca abeni
On Fri, 19 Oct 2018 13:39:42 +0200 Peter Zijlstra wrote: > On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > > Ok, I see the issue now: the problem is that the "while > > (dl_se->runtime <= 0)" loop is executed at replenishment time, but > > the deadline should be postponed at

Re: INFO: rcu detected stall in do_idle

2018-10-19 Thread luca abeni
On Fri, 19 Oct 2018 13:39:42 +0200 Peter Zijlstra wrote: > On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > > Ok, I see the issue now: the problem is that the "while > > (dl_se->runtime <= 0)" loop is executed at replenishment time, but > > the deadline should be postponed at

Re: INFO: rcu detected stall in do_idle

2018-10-19 Thread Peter Zijlstra
On Thu, Oct 18, 2018 at 12:33:32PM +0200, luca abeni wrote: > Hi Peter, > > On Thu, 18 Oct 2018 11:48:50 +0200 > Peter Zijlstra wrote: > [...] > > > So, I tend to think that we might want to play safe and put some > > > higher minimum value for dl_runtime (it's currently at 1ULL << > > >

Re: INFO: rcu detected stall in do_idle

2018-10-19 Thread Peter Zijlstra
On Thu, Oct 18, 2018 at 12:33:32PM +0200, luca abeni wrote: > Hi Peter, > > On Thu, 18 Oct 2018 11:48:50 +0200 > Peter Zijlstra wrote: > [...] > > > So, I tend to think that we might want to play safe and put some > > > higher minimum value for dl_runtime (it's currently at 1ULL << > > >

Re: INFO: rcu detected stall in do_idle

2018-10-19 Thread Peter Zijlstra
On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > Ok, I see the issue now: the problem is that the "while (dl_se->runtime > <= 0)" loop is executed at replenishment time, but the deadline should > be postponed at enforcement time. > > I mean: in update_curr_dl() we do: >

Re: INFO: rcu detected stall in do_idle

2018-10-19 Thread Peter Zijlstra
On Thu, Oct 18, 2018 at 01:08:11PM +0200, luca abeni wrote: > Ok, I see the issue now: the problem is that the "while (dl_se->runtime > <= 0)" loop is executed at replenishment time, but the deadline should > be postponed at enforcement time. > > I mean: in update_curr_dl() we do: >

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
Hi Juri, On Thu, 18 Oct 2018 14:21:42 +0200 Juri Lelli wrote: [...] > > > > I missed the original emails, but maybe the issue is that the > > > > task blocks before the tick, and when it wakes up again > > > > something goes wrong with the deadline and runtime assignment? > > > > (maybe because

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
Hi Juri, On Thu, 18 Oct 2018 14:21:42 +0200 Juri Lelli wrote: [...] > > > > I missed the original emails, but maybe the issue is that the > > > > task blocks before the tick, and when it wakes up again > > > > something goes wrong with the deadline and runtime assignment? > > > > (maybe because

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Juri Lelli
On 18/10/18 13:08, luca abeni wrote: > On Thu, 18 Oct 2018 12:47:13 +0200 > Juri Lelli wrote: > > > Hi, > > > > On 18/10/18 12:23, luca abeni wrote: > > > Hi Juri, > > > > > > On Thu, 18 Oct 2018 10:28:38 +0200 > > > Juri Lelli wrote: > > > [...] > > > > struct sched_attr { > > > >

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Juri Lelli
On 18/10/18 13:08, luca abeni wrote: > On Thu, 18 Oct 2018 12:47:13 +0200 > Juri Lelli wrote: > > > Hi, > > > > On 18/10/18 12:23, luca abeni wrote: > > > Hi Juri, > > > > > > On Thu, 18 Oct 2018 10:28:38 +0200 > > > Juri Lelli wrote: > > > [...] > > > > struct sched_attr { > > > >

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
On Thu, 18 Oct 2018 12:47:13 +0200 Juri Lelli wrote: > Hi, > > On 18/10/18 12:23, luca abeni wrote: > > Hi Juri, > > > > On Thu, 18 Oct 2018 10:28:38 +0200 > > Juri Lelli wrote: > > [...] > > > struct sched_attr { > > > .size = 0, > > > .policy = 6, > > > .flags=

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
On Thu, 18 Oct 2018 12:47:13 +0200 Juri Lelli wrote: > Hi, > > On 18/10/18 12:23, luca abeni wrote: > > Hi Juri, > > > > On Thu, 18 Oct 2018 10:28:38 +0200 > > Juri Lelli wrote: > > [...] > > > struct sched_attr { > > > .size = 0, > > > .policy = 6, > > > .flags=

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Juri Lelli
Hi, On 18/10/18 12:23, luca abeni wrote: > Hi Juri, > > On Thu, 18 Oct 2018 10:28:38 +0200 > Juri Lelli wrote: > [...] > > struct sched_attr { > > .size = 0, > > .policy = 6, > > .flags = 0, > > .nice = 0, > > .priority = 0, > > .runtime= 0x9917, > >

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Juri Lelli
Hi, On 18/10/18 12:23, luca abeni wrote: > Hi Juri, > > On Thu, 18 Oct 2018 10:28:38 +0200 > Juri Lelli wrote: > [...] > > struct sched_attr { > > .size = 0, > > .policy = 6, > > .flags = 0, > > .nice = 0, > > .priority = 0, > > .runtime= 0x9917, > >

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
Hi Juri, On Thu, 18 Oct 2018 12:10:08 +0200 Juri Lelli wrote: [...] > > Yes, a HZ related limit sounds like something we'd want. But if > > we're going to do a minimum sysctl, we should also consider adding > > a maximum, if you set a massive period/deadline, you can, even with > > a relatively

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
Hi Juri, On Thu, 18 Oct 2018 12:10:08 +0200 Juri Lelli wrote: [...] > > Yes, a HZ related limit sounds like something we'd want. But if > > we're going to do a minimum sysctl, we should also consider adding > > a maximum, if you set a massive period/deadline, you can, even with > > a relatively

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
Hi Peter, On Thu, 18 Oct 2018 11:48:50 +0200 Peter Zijlstra wrote: [...] > > So, I tend to think that we might want to play safe and put some > > higher minimum value for dl_runtime (it's currently at 1ULL << > > DL_SCALE). Guess the problem is to pick a reasonable value, though. > > Maybe link

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
Hi Peter, On Thu, 18 Oct 2018 11:48:50 +0200 Peter Zijlstra wrote: [...] > > So, I tend to think that we might want to play safe and put some > > higher minimum value for dl_runtime (it's currently at 1ULL << > > DL_SCALE). Guess the problem is to pick a reasonable value, though. > > Maybe link

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
Hi Juri, On Thu, 18 Oct 2018 10:28:38 +0200 Juri Lelli wrote: [...] > struct sched_attr { > .size = 0, > .policy = 6, > .flags= 0, > .nice = 0, > .priority = 0, > .runtime = 0x9917, > .deadline = 0x, > .period = 0, > } > > So, we seem to be

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread luca abeni
Hi Juri, On Thu, 18 Oct 2018 10:28:38 +0200 Juri Lelli wrote: [...] > struct sched_attr { > .size = 0, > .policy = 6, > .flags= 0, > .nice = 0, > .priority = 0, > .runtime = 0x9917, > .deadline = 0x, > .period = 0, > } > > So, we seem to be

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Juri Lelli
On 18/10/18 11:48, Peter Zijlstra wrote: > On Thu, Oct 18, 2018 at 10:28:38AM +0200, Juri Lelli wrote: > > > Another side problem seems also to be that with such tiny parameters we > > spend lot of time in the while (dl_se->runtime <= 0) loop of replenish_dl_ > > entity() (actually uselessly, as

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Juri Lelli
On 18/10/18 11:48, Peter Zijlstra wrote: > On Thu, Oct 18, 2018 at 10:28:38AM +0200, Juri Lelli wrote: > > > Another side problem seems also to be that with such tiny parameters we > > spend lot of time in the while (dl_se->runtime <= 0) loop of replenish_dl_ > > entity() (actually uselessly, as

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Peter Zijlstra
On Thu, Oct 18, 2018 at 10:28:38AM +0200, Juri Lelli wrote: > Another side problem seems also to be that with such tiny parameters we > spend lot of time in the while (dl_se->runtime <= 0) loop of replenish_dl_ > entity() (actually uselessly, as deadline is most probably going to > still be in

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Peter Zijlstra
On Thu, Oct 18, 2018 at 10:28:38AM +0200, Juri Lelli wrote: > Another side problem seems also to be that with such tiny parameters we > spend lot of time in the while (dl_se->runtime <= 0) loop of replenish_dl_ > entity() (actually uselessly, as deadline is most probably going to > still be in

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Juri Lelli
On 16/10/18 16:03, Peter Zijlstra wrote: > On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > > It does reproduce here but with a kworker stall. Looking at the reproducer: > > > > *(uint32_t*)0x2000 = 0; > > *(uint32_t*)0x2004 = 6; > > *(uint64_t*)0x2008 = 0; > >

Re: INFO: rcu detected stall in do_idle

2018-10-18 Thread Juri Lelli
On 16/10/18 16:03, Peter Zijlstra wrote: > On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > > It does reproduce here but with a kworker stall. Looking at the reproducer: > > > > *(uint32_t*)0x2000 = 0; > > *(uint32_t*)0x2004 = 6; > > *(uint64_t*)0x2008 = 0; > >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Juri Lelli
On 16/10/18 16:45, Thomas Gleixner wrote: > On Tue, 16 Oct 2018, Juri Lelli wrote: > > On 16/10/18 16:03, Peter Zijlstra wrote: > > > On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > > > > It does reproduce here but with a kworker stall. Looking at the > > > > reproducer: > > >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Juri Lelli
On 16/10/18 16:45, Thomas Gleixner wrote: > On Tue, 16 Oct 2018, Juri Lelli wrote: > > On 16/10/18 16:03, Peter Zijlstra wrote: > > > On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > > > > It does reproduce here but with a kworker stall. Looking at the > > > > reproducer: > > >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Thomas Gleixner
On Tue, 16 Oct 2018, Juri Lelli wrote: > On 16/10/18 16:03, Peter Zijlstra wrote: > > On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > > > It does reproduce here but with a kworker stall. Looking at the > > > reproducer: > > > > > > *(uint32_t*)0x2000 = 0; > > >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Thomas Gleixner
On Tue, 16 Oct 2018, Juri Lelli wrote: > On 16/10/18 16:03, Peter Zijlstra wrote: > > On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > > > It does reproduce here but with a kworker stall. Looking at the > > > reproducer: > > > > > > *(uint32_t*)0x2000 = 0; > > >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Juri Lelli
On 16/10/18 16:03, Peter Zijlstra wrote: > On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > > It does reproduce here but with a kworker stall. Looking at the reproducer: > > > > *(uint32_t*)0x2000 = 0; > > *(uint32_t*)0x2004 = 6; > > *(uint64_t*)0x2008 = 0; > >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Juri Lelli
On 16/10/18 16:03, Peter Zijlstra wrote: > On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > > It does reproduce here but with a kworker stall. Looking at the reproducer: > > > > *(uint32_t*)0x2000 = 0; > > *(uint32_t*)0x2004 = 6; > > *(uint64_t*)0x2008 = 0; > >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Peter Zijlstra
On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > It does reproduce here but with a kworker stall. Looking at the reproducer: > > *(uint32_t*)0x2000 = 0; > *(uint32_t*)0x2004 = 6; > *(uint64_t*)0x2008 = 0; > *(uint32_t*)0x2010 = 0; >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Peter Zijlstra
On Tue, Oct 16, 2018 at 03:24:06PM +0200, Thomas Gleixner wrote: > It does reproduce here but with a kworker stall. Looking at the reproducer: > > *(uint32_t*)0x2000 = 0; > *(uint32_t*)0x2004 = 6; > *(uint64_t*)0x2008 = 0; > *(uint32_t*)0x2010 = 0; >

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Thomas Gleixner
On Sat, 13 Oct 2018, syzbot wrote: > syzbot found the following crash on: > > HEAD commit:6b3944e42e2e afs: Fix cell proc list > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1545a47940 > kernel config:

Re: INFO: rcu detected stall in do_idle

2018-10-16 Thread Thomas Gleixner
On Sat, 13 Oct 2018, syzbot wrote: > syzbot found the following crash on: > > HEAD commit:6b3944e42e2e afs: Fix cell proc list > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1545a47940 > kernel config:

INFO: rcu detected stall in do_idle

2018-10-13 Thread syzbot
Hello, syzbot found the following crash on: HEAD commit:6b3944e42e2e afs: Fix cell proc list git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1545a47940 kernel config: https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d dashboard link:

INFO: rcu detected stall in do_idle

2018-10-13 Thread syzbot
Hello, syzbot found the following crash on: HEAD commit:6b3944e42e2e afs: Fix cell proc list git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1545a47940 kernel config: https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d dashboard link: