From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792713814; b=L5cz+CBYGtXloRJY0TXGXXln6srbQZg1S6FoG3ChCyjG2AHaWNeFauluWWygjFdOt/dc mzSdP4axVQR+X6zcG9LCb2glpHp0T/efpwJh46LbkUeb9EsdDc4XkVfHSwjDH33fTjHxY xul1i1cmqVmX5rDV7QW0lZZGMie1bazB8y/2VvvlPEVbkxUVTADq1g9guOEzTjRizrF6i cA1NXzxgt8vWgXRxcSMSozPXa4gnXKuZmMGLZfUnukTZ5Cj5vFQSRtKEQ8rgbWMTTiO06 LiMsuRTXhNM6ApS4TMh3QayEluqyuCZYXr7Twnj91jHpQwKjImfcLj57hxlhlFe2nqA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792713814; h=Received:DKIM-Signature:Date:Message-ID:From:To:Cc:Subject: In-Reply-To:References; bh=J7REHjKN4xxpRijalKL70zgjfl3Kdf8r5hcnizdaRCQ=; b=I0tO4wScc19fSis/Z9SsyfBfdd9jXOMFiXNPb/y3FyMNmZ1mpg+NjhZGi8GBDco7wwAI MVn71Yxt30qL9WV1ySJb1xFGhF+a7NzNZVzW9QtGuIZmdNTe38HE3yDi1CyWUfdt5+CyB mwbFLlWSP5sR6z2Kd2XT78JSU8n0uqas9srxl0JuUGByXhg6nGE4E6Mw/yypeofZoYjDj nsMb41EZs/oB03CZW5MJTmBmIMOGL7o0GqyTnT+nfjRwbAJsWFO9mWzIgA5OLu2ZyuSN5 sgmPdI1WnS/4NAoQXQsWVs9ODKEJyBOZqdPIGA7fA6L7XBCz2xGaRUKFORjnvKZ/DkQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=QfnDCyuy; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6D83F606A319; Fri, 23 Oct 2026 00:03:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=QfnDCyuy Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBA4B1F01825; Fri, 23 Oct 2026 00:03:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792713814; bh=J7REHjKN4xxpRijalKL70zgjfl3Kdf8r5hcnizdaRCQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=QfnDCyuy456Qt4VwBeBXDvOhynEj2hBYrbGZV2quU/3b5IGovJhrfRoQ7qYvLv7tl FV5iOLEKMx5IoHIqFbIOAr0IrjsYl0c+rnkUmMJr1Pown4SIHCZ/BB61cclrjo6pq+ AykG2uLg3VjVDnb10KpLJT7vnJk2JHsVqWa7xQPgGKtiTdM01+cand9Jr2MEL4eV8R XFEVw13Rc4twGIlEkpFFbuT9ZbUg7/60c0cMQsBXbMpWFD30QCGpazSdARhDMF7IqT 6Qf5AR0M6KUn6XJVAH+/GutIpt6Zc0zXFhB/lFlmeaSAAgsxEzG5+NNe0LcnYCmsa7 frCR5h9TJaEfg== Date: Thu, 22 Oct 2026 14:03:33 -1000 Message-ID: From: Tejun Heo To: sashiko-reviews@lists.linux.dev Cc: sashiko-bot@kernel.org, sched-ext@lists.linux.dev Subject: Re: [PATCH 10/14] sched_ext: Fix bypassed tasks stalling when the host lacks SCX_CAP_BASE In-Reply-To: References: <20261022213836.2259069-1-tj@kernel.org> <20261022213836.2259069-11-tj@kernel.org> X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Hello, On Thu, Oct 22, 2026 at 10:09:43PM +0000, sashiko-bot@kernel.org wrote: > [Severity: High] > Should the initial slice check in dispatch_one() also allow a task with > scx_task_has_kernel_slice(prev) to keep running while its scheduler is > bypassing, matching put_prev_task_scx()? Yes, it should keep the rescuee. The next version adds a patch ahead of this one. It expires a bypassing prev's slice in dispatch_one() before the keep test and drops the bypass test from the keep test. A kernel slice survives the expiry, so a bypassed rescuee keeps the CPU. The post-dispatch test in scx_dispatch_sched() also can no longer keep a prev that dispatch_one() declined. Thanks. -- tejun