From: Dietmar Eggemann <dietmar.eggemann@arm.com> To: Will Deacon <will@kernel.org> Cc: Daniel Bristot de Oliveira <bristot@redhat.com>, Quentin Perret <qperret@google.com>, Juri Lelli <juri.lelli@redhat.com>, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>, Marc Zyngier <maz@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Peter Zijlstra <peterz@infradead.org>, Morten Rasmussen <morten.rasmussen@arm.com>, Qais Yousef <qais.yousef@arm.com>, Suren Baghdasaryan <surenb@google.com>, Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>, Ingo Molnar <mingo@redhat.com>, Vincent Guittot <vincent.guittot@linaro.org>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, kernel-team@android.com Subject: Re: [PATCH v6 13/21] sched: Admit forcefully-affined tasks into SCHED_DEADLINE Date: Fri, 21 May 2021 13:26:10 +0200 [thread overview] Message-ID: <2055b1d4-ef42-0f49-6a0c-40c8415ef945@arm.com> (raw) In-Reply-To: <20210520180318.GB10523@willie-the-truck> On 20/05/2021 20:03, Will Deacon wrote: > Hi Dietmar, > > On Thu, May 20, 2021 at 07:55:27PM +0200, Dietmar Eggemann wrote: >> On 20/05/2021 18:00, Daniel Bristot de Oliveira wrote: >>> On 5/20/21 5:06 PM, Dietmar Eggemann wrote: >>>> (1) # chrt -d -T 5000000 -P 16666666 0 ./32bit_app >>>> >>>> (2) # ./32bit_app & >>>> >>>> # chrt -d -T 5000000 -P 16666666 -p 0 pid_of(32bit_app) >>>> >>>> >>>> Wouldn't the behaviour of (1) and (2) be different w/o this patch? >>>> >>>> In (1) __sched_setscheduler() happens before execve so it operates on >>>> p->cpus_ptr equal span. >>>> >>>> In (2) span != p->cpus_ptr so DL AC will fail. >>>> >>> >>> As far as I got, the case (1) would be spitted in two steps: >>> >>> - __sched_setscheduler() will work, then >>> - execv() would fail because (span != p->cpus_ptr) >>> >>> So... at the end, both (1) and (2) would result in a failure... >>> >>> am I missing something? >> >> Not sure. Reading this thread I was under the assumption that the only >> change would be the drop of this patch. But I assume there is also this >> 'if DL AC is on then let sched_setattr() fail for this 32bit task'. >> >> IMHO, the current patch-stack w/o this patch should let (1) succeed with >> DL AC. > > That's what I'm proposing, yes, but others (including Daniel) prefer to > fail the execve(). See my other reply just now for a summary [1]. [...] Thanks, Will ... Now I understand. Or at least I think I do ;-) > [1] https://lore.kernel.org/lkml/20210520180138.GA10523@willie-the-truck/T/#u
WARNING: multiple messages have this Message-ID (diff)
From: Dietmar Eggemann <dietmar.eggemann@arm.com> To: Will Deacon <will@kernel.org> Cc: Daniel Bristot de Oliveira <bristot@redhat.com>, Quentin Perret <qperret@google.com>, Juri Lelli <juri.lelli@redhat.com>, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>, Marc Zyngier <maz@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Peter Zijlstra <peterz@infradead.org>, Morten Rasmussen <morten.rasmussen@arm.com>, Qais Yousef <qais.yousef@arm.com>, Suren Baghdasaryan <surenb@google.com>, Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>, Ingo Molnar <mingo@redhat.com>, Vincent Guittot <vincent.guittot@linaro.org>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, kernel-team@android.com Subject: Re: [PATCH v6 13/21] sched: Admit forcefully-affined tasks into SCHED_DEADLINE Date: Fri, 21 May 2021 13:26:10 +0200 [thread overview] Message-ID: <2055b1d4-ef42-0f49-6a0c-40c8415ef945@arm.com> (raw) In-Reply-To: <20210520180318.GB10523@willie-the-truck> On 20/05/2021 20:03, Will Deacon wrote: > Hi Dietmar, > > On Thu, May 20, 2021 at 07:55:27PM +0200, Dietmar Eggemann wrote: >> On 20/05/2021 18:00, Daniel Bristot de Oliveira wrote: >>> On 5/20/21 5:06 PM, Dietmar Eggemann wrote: >>>> (1) # chrt -d -T 5000000 -P 16666666 0 ./32bit_app >>>> >>>> (2) # ./32bit_app & >>>> >>>> # chrt -d -T 5000000 -P 16666666 -p 0 pid_of(32bit_app) >>>> >>>> >>>> Wouldn't the behaviour of (1) and (2) be different w/o this patch? >>>> >>>> In (1) __sched_setscheduler() happens before execve so it operates on >>>> p->cpus_ptr equal span. >>>> >>>> In (2) span != p->cpus_ptr so DL AC will fail. >>>> >>> >>> As far as I got, the case (1) would be spitted in two steps: >>> >>> - __sched_setscheduler() will work, then >>> - execv() would fail because (span != p->cpus_ptr) >>> >>> So... at the end, both (1) and (2) would result in a failure... >>> >>> am I missing something? >> >> Not sure. Reading this thread I was under the assumption that the only >> change would be the drop of this patch. But I assume there is also this >> 'if DL AC is on then let sched_setattr() fail for this 32bit task'. >> >> IMHO, the current patch-stack w/o this patch should let (1) succeed with >> DL AC. > > That's what I'm proposing, yes, but others (including Daniel) prefer to > fail the execve(). See my other reply just now for a summary [1]. [...] Thanks, Will ... Now I understand. Or at least I think I do ;-) > [1] https://lore.kernel.org/lkml/20210520180138.GA10523@willie-the-truck/T/#u _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-05-21 11:26 UTC|newest] Thread overview: 166+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-18 9:47 [PATCH v6 00/21] Add support for 32-bit tasks on asymmetric AArch32 systems Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 01/21] arm64: cpuinfo: Split AArch32 registers out into a separate struct Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 10:47 ` Catalin Marinas 2021-05-21 10:47 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 02/21] arm64: Allow mismatched 32-bit EL0 support Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 10:25 ` Catalin Marinas 2021-05-21 10:25 ` Catalin Marinas 2021-05-24 12:05 ` Will Deacon 2021-05-24 12:05 ` Will Deacon 2021-05-24 13:49 ` Catalin Marinas 2021-05-24 13:49 ` Catalin Marinas 2021-05-21 10:41 ` Catalin Marinas 2021-05-21 10:41 ` Catalin Marinas 2021-05-24 12:09 ` Will Deacon 2021-05-24 12:09 ` Will Deacon 2021-05-24 13:46 ` Catalin Marinas 2021-05-24 13:46 ` Catalin Marinas 2021-05-21 15:22 ` Qais Yousef 2021-05-21 15:22 ` Qais Yousef 2021-05-24 20:21 ` Will Deacon 2021-05-24 20:21 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 03/21] KVM: arm64: Kill 32-bit vCPUs on systems with mismatched " Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 10:47 ` Catalin Marinas 2021-05-21 10:47 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 04/21] arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 10:55 ` Catalin Marinas 2021-05-21 10:55 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 05/21] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 11:00 ` Catalin Marinas 2021-05-21 11:00 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 06/21] sched: Introduce task_cpu_possible_mask() to limit fallback rq selection Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 16:03 ` Peter Zijlstra 2021-05-21 16:03 ` Peter Zijlstra 2021-05-24 12:17 ` Will Deacon 2021-05-24 12:17 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 07/21] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 17:39 ` Qais Yousef 2021-05-21 17:39 ` Qais Yousef 2021-05-24 20:21 ` Will Deacon 2021-05-24 20:21 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 08/21] cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus() Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 16:25 ` Qais Yousef 2021-05-21 16:25 ` Qais Yousef 2021-05-24 21:09 ` Will Deacon 2021-05-24 21:09 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 09/21] sched: Reject CPU affinity changes based on task_cpu_possible_mask() Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 10/21] sched: Introduce task_struct::user_cpus_ptr to track requested affinity Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 11/21] sched: Split the guts of sched_setaffinity() into a helper function Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 16:41 ` Qais Yousef 2021-05-21 16:41 ` Qais Yousef 2021-05-24 21:16 ` Will Deacon 2021-05-24 21:16 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 12/21] sched: Allow task CPU affinity to be restricted on asymmetric systems Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 17:11 ` Qais Yousef 2021-05-21 17:11 ` Qais Yousef 2021-05-24 21:43 ` Will Deacon 2021-05-24 21:43 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 13/21] sched: Admit forcefully-affined tasks into SCHED_DEADLINE Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-18 10:20 ` Quentin Perret 2021-05-18 10:20 ` Quentin Perret 2021-05-18 10:28 ` Will Deacon 2021-05-18 10:28 ` Will Deacon 2021-05-18 10:48 ` Quentin Perret 2021-05-18 10:48 ` Quentin Perret 2021-05-18 10:59 ` Will Deacon 2021-05-18 10:59 ` Will Deacon 2021-05-18 13:19 ` Quentin Perret 2021-05-18 13:19 ` Quentin Perret 2021-05-20 9:13 ` Juri Lelli 2021-05-20 9:13 ` Juri Lelli 2021-05-20 10:16 ` Will Deacon 2021-05-20 10:16 ` Will Deacon 2021-05-20 10:33 ` Quentin Perret 2021-05-20 10:33 ` Quentin Perret 2021-05-20 12:38 ` Juri Lelli 2021-05-20 12:38 ` Juri Lelli 2021-05-20 12:38 ` Daniel Bristot de Oliveira 2021-05-20 12:38 ` Daniel Bristot de Oliveira 2021-05-20 15:06 ` Dietmar Eggemann 2021-05-20 15:06 ` Dietmar Eggemann 2021-05-20 16:00 ` Daniel Bristot de Oliveira 2021-05-20 16:00 ` Daniel Bristot de Oliveira 2021-05-20 17:55 ` Dietmar Eggemann 2021-05-20 17:55 ` Dietmar Eggemann 2021-05-20 18:03 ` Will Deacon 2021-05-20 18:03 ` Will Deacon 2021-05-21 11:26 ` Dietmar Eggemann [this message] 2021-05-21 11:26 ` Dietmar Eggemann 2021-05-20 18:01 ` Will Deacon 2021-05-20 18:01 ` Will Deacon 2021-05-21 5:25 ` Juri Lelli 2021-05-21 5:25 ` Juri Lelli 2021-05-21 8:15 ` Quentin Perret 2021-05-21 8:15 ` Quentin Perret 2021-05-21 8:39 ` Juri Lelli 2021-05-21 8:39 ` Juri Lelli 2021-05-21 10:37 ` Will Deacon 2021-05-21 10:37 ` Will Deacon 2021-05-21 11:23 ` Dietmar Eggemann 2021-05-21 11:23 ` Dietmar Eggemann 2021-05-21 13:02 ` Quentin Perret 2021-05-21 13:02 ` Quentin Perret 2021-05-21 14:04 ` Juri Lelli 2021-05-21 14:04 ` Juri Lelli 2021-05-21 17:47 ` Dietmar Eggemann 2021-05-21 17:47 ` Dietmar Eggemann 2021-05-21 13:00 ` Daniel Bristot de Oliveira 2021-05-21 13:00 ` Daniel Bristot de Oliveira 2021-05-21 13:12 ` Quentin Perret 2021-05-21 13:12 ` Quentin Perret 2021-05-24 20:47 ` Will Deacon 2021-05-24 20:47 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 14/21] freezer: Add frozen_or_skipped() helper function Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 15/21] sched: Defer wakeup in ttwu() for unschedulable frozen tasks Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-18 9:47 ` [PATCH v6 16/21] arm64: Implement task_cpu_possible_mask() Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-24 14:57 ` Catalin Marinas 2021-05-24 14:57 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 17/21] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-24 15:02 ` Catalin Marinas 2021-05-24 15:02 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 18/21] arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-24 15:46 ` Catalin Marinas 2021-05-24 15:46 ` Catalin Marinas 2021-05-24 20:32 ` Will Deacon 2021-05-24 20:32 ` Will Deacon 2021-05-25 9:43 ` Catalin Marinas 2021-05-25 9:43 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 19/21] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-24 15:47 ` Catalin Marinas 2021-05-24 15:47 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 20/21] arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-24 15:47 ` Catalin Marinas 2021-05-24 15:47 ` Catalin Marinas 2021-05-18 9:47 ` [PATCH v6 21/21] Documentation: arm64: describe asymmetric 32-bit support Will Deacon 2021-05-18 9:47 ` Will Deacon 2021-05-21 17:37 ` Qais Yousef 2021-05-21 17:37 ` Qais Yousef 2021-05-24 21:46 ` Will Deacon 2021-05-24 21:46 ` Will Deacon 2021-05-24 16:22 ` Catalin Marinas 2021-05-24 16:22 ` Catalin Marinas 2021-05-21 17:45 ` [PATCH v6 00/21] Add support for 32-bit tasks on asymmetric AArch32 systems Qais Yousef 2021-05-21 17:45 ` Qais Yousef 2021-05-24 22:08 ` Will Deacon 2021-05-24 22:08 ` Will Deacon
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