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From: Tejun Heo <tj@kernel.org>
To: David Vernet <void@manifault.com>,
	Andrea Righi <arighi@nvidia.com>,
	Changwoo Min <changwoo@igalia.com>
Cc: sched-ext@lists.linux.dev, Emil Tsalapatis <emil@etsalapatis.com>,
	linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>
Subject: [PATCHSET sched_ext/for-7.3] sched_ext: Sub-scheduler and cid fixes
Date: Sun, 19 Jul 2026 22:26:02 -1000	[thread overview]
Message-ID: <20260720082605.1451945-1-tj@kernel.org> (raw)

Hello,

A few fixes for the sub-scheduler and cid-form code on for-7.3.

- 0001 attributes a runnable stall to the scheduler that owns the DSQ the
  task is stuck on rather than the task's owner, so a bypassing sub's task
  parked on an ancestor's bypass DSQ blames the ancestor, not the sub.

- 0002 skips the default CPU selection while bypassing. The pick is discarded
  by the bypass enqueue anyway, and it consults idle masks a scheduler doing
  its own idle tracking leaves frozen.

- 0003 guards the cid kfuncs against the cid tables not being allocated yet,
  which a program can hit while racing the first scheduler enable.

Based on sched_ext/for-7.3 (b20dfde5ec54).

Tejun Heo (3):
  sched_ext: Blame the DSQ's owning scheduler for a runnable stall
  sched_ext: Skip the default CPU selection while bypassing
  sched_ext: Guard the cid kfuncs against unallocated cid tables

Git tree: git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git scx-sub-fixes

 kernel/sched/ext/cid.c |  5 +++--
 kernel/sched/ext/cid.h | 23 +++++++++++++++--------
 kernel/sched/ext/ext.c | 26 ++++++++++++++++++++++++--
 3 files changed, 42 insertions(+), 12 deletions(-)

--
tejun

             reply	other threads:[~2026-07-20  8:26 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-20  8:26 Tejun Heo [this message]
2026-07-20  8:26 ` [PATCH 1/3] sched_ext: Blame the DSQ's owning scheduler for a runnable stall Tejun Heo
2026-07-20  8:26 ` [PATCH 2/3] sched_ext: Skip the default CPU selection while bypassing Tejun Heo
2026-07-20  8:26 ` [PATCH 3/3] sched_ext: Guard the cid kfuncs against unallocated cid tables Tejun Heo
2026-07-20  9:41   ` Andrea Righi

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