From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 29C401F9F5B; Mon, 13 Jan 2025 18:35:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736793306; cv=none; b=lQXIaGifiy3qKOjbCxS2me5vBCanLmw8gvE6c2/VcgHUSkrhOP02wzft1YWri5AuRc9Qe6Fs2TRaAqPP3E7+NslwXgBRhOiTxe+gcVJeihrNySFXygPcPbZ1IB2LFb5W06CupxeiUuGPtn+OEIzTuojg5Y2pczjPEQ4AzQxGv3Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736793306; c=relaxed/simple; bh=oCs/GBdCg29DHR59+pTCj8OWhkpbOT7d3Ht7oLrBVHA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=dfCIT/mdXQY2AHcgi8W6ZhudkWeYm7gy3TSsH7EgZjQ8sqK1xIjrUpV0HU2ccEUvglaMdvDMruh7ffLD8aongPTNu8ONW6/Xb7vSNVE27jNhsXMYzhMzx8hq24bHqkrKJ2LgZ6frp+UGYorZgcPnnOrR3duHx0iImBp4DH/Mj6s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ew6Und3C; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ew6Und3C" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1B55C4CEE5; Mon, 13 Jan 2025 18:35:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736793305; bh=oCs/GBdCg29DHR59+pTCj8OWhkpbOT7d3Ht7oLrBVHA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ew6Und3CPK/982QseOTJJxhwDif40BoHugrOrCF48GZ04x9ga8zsLwuC+uYzV0PLf wAfwlkoh/UgHnkxcZst8Xy7dbV9JMDfltw4bFiVvj9dvKPXP9mC//UaMsQZhWsEaOS 9SCRaLgp0e7oShrXT3o8UxCn4GAbISD7W49Xfd8zFXVS4EoKW8lSx5GAJX4eHSadje OuvjOQBQMmzUds+pMt3GfPzjJX8tkXbUxlGFSZyEaST7lNPI3vX2WxQ7GDFHd8elw/ zFN1V8/pDZFWbKzal9meDe8de+8ufiTMcEbkkPM3p/POUrmpKEoKr4JZnmSU+MAu3b L7rjobn5W73mg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Henry Huang , Andrea Righi , Tejun Heo , Sasha Levin , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org Subject: [PATCH AUTOSEL 6.12 17/20] sched_ext: keep running prev when prev->scx.slice != 0 Date: Mon, 13 Jan 2025 13:34:22 -0500 Message-Id: <20250113183425.1783715-17-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250113183425.1783715-1-sashal@kernel.org> References: <20250113183425.1783715-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.9 Content-Transfer-Encoding: 8bit From: Henry Huang [ Upstream commit 30dd3b13f9de612ef7328ccffcf1a07d0d40ab51 ] When %SCX_OPS_ENQ_LAST is set and prev->scx.slice != 0, @prev will be dispacthed into the local DSQ in put_prev_task_scx(). However, pick_task_scx() is executed before put_prev_task_scx(), so it will not pick @prev. Set %SCX_RQ_BAL_KEEP in balance_one() to ensure that pick_task_scx() can pick @prev. Signed-off-by: Henry Huang Acked-by: Andrea Righi Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- kernel/sched/ext.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 40f915f893e2..7e217761854b 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2630,6 +2630,7 @@ static int balance_one(struct rq *rq, struct task_struct *prev) { struct scx_dsp_ctx *dspc = this_cpu_ptr(scx_dsp_ctx); bool prev_on_scx = prev->sched_class == &ext_sched_class; + bool prev_on_rq = prev->scx.flags & SCX_TASK_QUEUED; int nr_loops = SCX_DSP_MAX_LOOPS; lockdep_assert_rq_held(rq); @@ -2662,8 +2663,7 @@ static int balance_one(struct rq *rq, struct task_struct *prev) * See scx_ops_disable_workfn() for the explanation on the * bypassing test. */ - if ((prev->scx.flags & SCX_TASK_QUEUED) && - prev->scx.slice && !scx_rq_bypassing(rq)) { + if (prev_on_rq && prev->scx.slice && !scx_rq_bypassing(rq)) { rq->scx.flags |= SCX_RQ_BAL_KEEP; goto has_tasks; } @@ -2696,6 +2696,10 @@ static int balance_one(struct rq *rq, struct task_struct *prev) flush_dispatch_buf(rq); + if (prev_on_rq && prev->scx.slice) { + rq->scx.flags |= SCX_RQ_BAL_KEEP; + goto has_tasks; + } if (rq->scx.local_dsq.nr) goto has_tasks; if (consume_global_dsq(rq)) @@ -2721,8 +2725,7 @@ static int balance_one(struct rq *rq, struct task_struct *prev) * Didn't find another task to run. Keep running @prev unless * %SCX_OPS_ENQ_LAST is in effect. */ - if ((prev->scx.flags & SCX_TASK_QUEUED) && - (!static_branch_unlikely(&scx_ops_enq_last) || + if (prev_on_rq && (!static_branch_unlikely(&scx_ops_enq_last) || scx_rq_bypassing(rq))) { rq->scx.flags |= SCX_RQ_BAL_KEEP; goto has_tasks; -- 2.39.5