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From: Tejun Heo <tj@kernel.org>
To: sashiko-reviews@lists.linux.dev
Cc: sashiko-bot@kernel.org, sched-ext@lists.linux.dev
Subject: Re: [PATCH 14/14] sched_ext: Fix queued bypassed tasks stalling when the host loses SCX_CAP_BASE
Date: Thu, 22 Oct 2026 14:03:34 -1000	[thread overview]
Message-ID: <9c649b0fa1c5d1593305e18b8bf8f23f@kernel.org> (raw)
In-Reply-To: <sashiko-outbox-182094@kernel.org>

Hello,

On Thu, Oct 22, 2026 at 10:04:04PM +0000, sashiko-bot@kernel.org wrote:
> [Severity: High]
> Can passing SCX_ENQ_REENQ from bypass_lb_reenq_home() to
> scx_do_enqueue_task() strand p off all DSQs when p->scx.reenq_cnt exceeds
> SCX_REENQ_MAX_REPEAT?

Same as on patch 3, this is intended. Going past the reenqueue limit
means that the scheduler malfunctioned, so it is aborted and its exit
path picks up the stranded task, as the comment above the check says.

Thanks.

--
tejun

      reply	other threads:[~2026-10-23  0:03 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-22 21:38 [PATCHSET sched_ext/for-7.4] sched_ext: Fix bypassed sub-scheduler tasks stalling when the host lacks caps Tejun Heo
2026-10-22 21:38 ` [PATCH 01/14] sched_ext: Pack scx_ent_flags' multi-bit fields at the top Tejun Heo
2026-10-22 21:38 ` [PATCH 02/14] sched_ext: Clear holding_cpu where the claim is confirmed Tejun Heo
2026-10-22 21:38 ` [PATCH 03/14] sched_ext: Fix bypassed tasks looping on a host without SCX_CAP_ENQ Tejun Heo
2026-10-22 22:04   ` sashiko-bot
2026-10-23  0:03     ` Tejun Heo
2026-10-22 21:38 ` [PATCH 04/14] sched_ext: Move refill_task_slice_dfl() below apply_slice_vtime() Tejun Heo
2026-10-22 21:38 ` [PATCH 05/14] sched_ext: Restore a rescuee's slice after ops.stopping() Tejun Heo
2026-10-22 21:38 ` [PATCH 06/14] sched_ext: Fix a cpu idling with a runnable rescuee Tejun Heo
2026-10-22 21:56   ` sashiko-bot
2026-10-23  0:03     ` Tejun Heo
2026-10-22 21:38 ` [PATCH 07/14] sched_ext: Mark the rescue grant as a kernel slice with SCX_TASK_KERNEL_SLICE Tejun Heo
2026-10-22 21:38 ` [PATCH 08/14] sched_ext: Refuse extending a kernel slice Tejun Heo
2026-10-22 21:38 ` [PATCH 09/14] sched_ext: Fix a cpu idling after put_prev_task_scx() queues its task on the local DSQ Tejun Heo
2026-10-22 21:38 ` [PATCH 10/14] sched_ext: Fix bypassed tasks stalling when the host lacks SCX_CAP_BASE Tejun Heo
2026-10-22 22:09   ` sashiko-bot
2026-10-23  0:03     ` Tejun Heo
2026-10-22 21:38 ` [PATCH 11/14] sched_ext: Fix the bypass load balancer stranding tasks on cpus where " Tejun Heo
2026-10-22 21:38 ` [PATCH 12/14] sched_ext: Factor out bypass_lb_move() and insert with the donor DSQ unlocked Tejun Heo
2026-10-22 21:38 ` [PATCH 13/14] sched_ext: Let the bypass load balancer move tasks homed on other cpus Tejun Heo
2026-10-22 21:38 ` [PATCH 14/14] sched_ext: Fix queued bypassed tasks stalling when the host loses SCX_CAP_BASE Tejun Heo
2026-10-22 22:04   ` sashiko-bot
2026-10-23  0:03     ` Tejun Heo [this message]

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