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=1792782503; b=KLKCeIJrqgEuBe7HdzQjjwjxSN/x9aPq1kMSvyV85GhToMGDB0Z2oFtrdKFBAr4jVZ52 ruHIuEYVWyrxefbCqsVrtDdbNGJmlhLGun5WEL50aMmrUfXrCVOpqDXguiEjNwfhvCBdV +1sArNJurJHccoy+H0tsK2TvQHsDza2Z+pswQW5RjgJTvSPhlcTp/o6Kxtl7sLRkF063m A/4aL1XsOKKDt0Be3MJVHzU5jzaA+RNg+ACAIFJh3RgBdaBrxLQfEOyKgD3VVeoGF9PfQ +DodixohiiL4vzOVDA8bB6JN+MVmt8QlUl0PecekGLrjdzMg1yK9Eg9c+rARvuiM+cQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792782503; h=Received:DKIM-Signature:Date:Message-ID:From:To:Cc:Subject: In-Reply-To:References; bh=R1XDwPK3N6z98u0rI3lwvWfhQAjAT5zkSIvMagPum8Y=; b=d2jtH9XiVgBy8Xk0V/zAR22XR6i5ynEzPMF1yih20/m7KAJfEKUSPdCH0t9ZPfVC0BY+ WEnz7hVzFwS5Bipxhi0y0XXhoOZ3puS4YL0qB4KxRrtQh2YiREZeWOBDHUA9X5ZeuW/Zr DLtQLR3G9fNS6XWZmYarSyMPJ6NEqBF+gaSLK40gzYpLBPvnYQ9+FSloumS1v1SqMIAcd l2axW3M3diJHxAQYcBo4Q3Io9I85KaCqh3NdiVzvdPIqSQs0VL1Oj/peappyX+jfRHWy7 zP3FySMU6Cp9Zer1YfKjQREN4N95dCgyHS6UAmdHT2E11WaX6GeeYeCFqZeg62oceIg== 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=NKGdaolC; 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 A9241606A31A; Fri, 23 Oct 2026 19:08:22 +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=NKGdaolC Received: by smtp.kernel.org (Postfix) with ESMTPSA id 235A71F01825; Fri, 23 Oct 2026 19:08:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792782502; bh=R1XDwPK3N6z98u0rI3lwvWfhQAjAT5zkSIvMagPum8Y=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=NKGdaolCI6kxHVHFqUjYNuEZj3L+ZMY5YG+DtLZ2oVAg6IUfwS2JucQ1C2aaY0juM uC1daI0zm27yT/f3cok3UoxtoGFJvGypIqt7qYFE3aIqIZ8MmTiUvRvys0lDwkEpGj v5uuqlR1hX1IPRtYlbtmuVzGH5/NdpgBfnGBUftQZ5Q78OY3ZmhCEao1U7IyRncKK1 PwXDXlv8fLjoZBf5x4/2UGdKxy83mvL2nDLBrA3FGtladVKIHQfHQQlMUud7UjELzO 7fZnXNCXf8xv0TckPMLbgzZYl3j8wSN7YYjvTEd/gftI7sZ1n1lSHniz+pIAxtBzjj HcDoKloC8TmMw== Date: Fri, 23 Oct 2026 09:08:21 -1000 Message-ID: <6f2d7109b2e68b12157f94841f929249@kernel.org> From: Tejun Heo To: sashiko-reviews@lists.linux.dev Cc: sashiko-bot@kernel.org, sched-ext@lists.linux.dev Subject: Re: [PATCH 04/17] sched_ext: Fix bypassed tasks looping on a host without SCX_CAP_ENQ In-Reply-To: References: <20261023175608.4120910-1-tj@kernel.org> <20261023175608.4120910-5-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 Fri, Oct 23, 2026 at 06:50:45PM +0000, sashiko-bot@kernel.org wrote: > [Severity: Medium] > Can a bypassed task consumed with SCX_ENQ_IMMED get left waiting on > rq->scx.local_dsq without being reenqueued when dispatch_one() finishes with > SCX_DSP_PREV? ... > Should the check at has_tasks in dispatch_one() also trigger > scx_schedule_reenq_local() when verdict == SCX_DSP_PREV and rq->scx.nr_immed > is non-zero, such as checking (rq->scx.local_dsq.nr > 1 || verdict == > SCX_DSP_PREV) && rq->scx.nr_immed? The only way to get there is the parent keeping prev after dispatching its children. The suggested change looks harmless though. I'll follow up with it as a separate patch. Thanks. -- tejun