From: Tejun Heo <tj@kernel.org>
To: Josh Don <joshdon@google.com>
Cc: torvalds@linux-foundation.org, mingo@redhat.com,
peterz@infradead.org, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
bristot@redhat.com, vschneid@redhat.com, ast@kernel.org,
daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org,
brho@google.com, pjt@google.com, derkling@google.com,
haoluo@google.com, dvernet@meta.com, dschatzberg@meta.com,
dskarlat@cs.cmu.edu, riel@surriel.com,
linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
kernel-team@meta.com
Subject: Re: [PATCH 27/30] sched_ext: Implement core-sched support
Date: Mon, 30 Jan 2023 14:36:25 -1000 [thread overview]
Message-ID: <Y9hiifiFx4TeUdTo@slm.duckdns.org> (raw)
In-Reply-To: <Y9hgLENFI5y3Qtx2@slm.duckdns.org>
On Mon, Jan 30, 2023 at 02:26:20PM -1000, Tejun Heo wrote:
> However, the BPF scheduler is free to dispatch whatever tasks anytime (e.g.
> scx_example_central), so it's possible that a task with an earlier timestamp
> has been dispatched to the local DSQ since curr started executing, in which
> case we likely want to return the first on DSQ as the CPU's candidate.
Okay, a more common case would be when a CPU is forced to run a task which
isn't current by its sibling winning a different cookie and then the BPF
scheduler putting that task right back on the local DSQ. For the CPU then,
the right candidate would be the first task on DSQ not the current running
one which is dragged forward because the sibling trumping us.
Thanks.
--
tejun
next prev parent reply other threads:[~2023-01-31 0:36 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-28 0:16 [PATCHSET v2] sched: Implement BPF extensible scheduler class Tejun Heo
2023-01-28 0:16 ` [PATCH 01/30] cgroup: Implement cgroup_show_cftypes() Tejun Heo
2023-01-28 0:16 ` [PATCH 02/30] sched: Encapsulate task attribute change sequence into a helper macro Tejun Heo
2023-01-28 0:16 ` [PATCH 03/30] sched: Restructure sched_class order sanity checks in sched_init() Tejun Heo
2023-01-28 0:16 ` [PATCH 04/30] sched: Allow sched_cgroup_fork() to fail and introduce sched_cancel_fork() Tejun Heo
2023-01-28 0:16 ` [PATCH 05/30] sched: Add sched_class->reweight_task() Tejun Heo
2023-01-28 0:16 ` [PATCH 06/30] sched: Add sched_class->switching_to() and expose check_class_changing/changed() Tejun Heo
2023-01-28 0:16 ` [PATCH 07/30] sched: Factor out cgroup weight conversion functions Tejun Heo
2023-01-28 0:16 ` [PATCH 08/30] sched: Expose css_tg(), __setscheduler_prio() and SCHED_CHANGE_BLOCK() Tejun Heo
2023-01-28 17:24 ` kernel test robot
2023-01-28 0:16 ` [PATCH 09/30] sched: Enumerate CPU cgroup file types Tejun Heo
2023-01-28 0:16 ` [PATCH 10/30] sched: Add @reason to sched_class->rq_{on|off}line() Tejun Heo
2023-01-28 0:16 ` [PATCH 11/30] sched: Add normal_policy() Tejun Heo
2023-01-28 0:16 ` [PATCH 12/30] sched_ext: Add boilerplate for extensible scheduler class Tejun Heo
2023-01-28 0:16 ` [PATCH 13/30] sched_ext: Implement BPF " Tejun Heo
2023-01-28 0:16 ` [PATCH 14/30] sched_ext: Add scx_example_dummy and scx_example_qmap example schedulers Tejun Heo
2023-01-28 0:16 ` [PATCH 15/30] sched_ext: Add sysrq-S which disables the BPF scheduler Tejun Heo
2023-01-28 0:16 ` [PATCH 16/30] sched_ext: Implement runnable task stall watchdog Tejun Heo
2023-01-28 0:16 ` [PATCH 17/30] sched_ext: Allow BPF schedulers to disallow specific tasks from joining SCHED_EXT Tejun Heo
2023-01-28 0:16 ` [PATCH 18/30] sched_ext: Allow BPF schedulers to switch all eligible tasks into sched_ext Tejun Heo
2023-01-28 0:16 ` [PATCH 19/30] sched_ext: Implement scx_bpf_kick_cpu() and task preemption support Tejun Heo
2023-01-28 0:16 ` [PATCH 20/30] sched_ext: Make watchdog handle ops.dispatch() looping stall Tejun Heo
2023-01-28 0:16 ` [PATCH 21/30] sched_ext: Add task state tracking operations Tejun Heo
2023-01-28 0:16 ` [PATCH 22/30] sched_ext: Implement tickless support Tejun Heo
2023-01-28 0:16 ` [PATCH 23/30] sched_ext: Add cgroup support Tejun Heo
2023-01-28 18:05 ` kernel test robot
2023-01-30 23:41 ` Tejun Heo
2023-01-28 0:16 ` [PATCH 24/30] sched_ext: Implement SCX_KICK_WAIT Tejun Heo
2023-01-28 0:16 ` [PATCH 25/30] sched_ext: Implement sched_ext_ops.cpu_acquire/release() Tejun Heo
2023-01-28 0:16 ` [PATCH 26/30] sched_ext: Implement sched_ext_ops.cpu_online/offline() Tejun Heo
2023-01-28 0:16 ` [PATCH 27/30] sched_ext: Implement core-sched support Tejun Heo
2023-01-28 19:07 ` kernel test robot
2023-01-30 21:38 ` Josh Don
2023-01-31 0:26 ` Tejun Heo
2023-01-31 0:36 ` Tejun Heo [this message]
2023-01-31 1:45 ` Josh Don
2023-01-28 0:16 ` [PATCH 28/30] sched_ext: Documentation: scheduler: Document extensible scheduler class Tejun Heo
2023-01-28 0:16 ` [PATCH 29/30] sched_ext: Add a basic, userland vruntime scheduler Tejun Heo
2023-01-28 0:16 ` [PATCH 30/30] sched_ext: Add a rust userspace hybrid example scheduler Tejun Heo
2023-02-08 21:55 ` [PATCHSET v2] sched: Implement BPF extensible scheduler class Tejun Heo
-- strict thread matches above, loose matches on Subject: below --
2024-06-18 21:17 [PATCHSET v7] " Tejun Heo
2024-06-18 21:17 ` [PATCH 27/30] sched_ext: Implement core-sched support Tejun Heo
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