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 D4B57128816; Tue, 30 Apr 2024 10:57:27 +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=1714474647; cv=none; b=bvwjD1NivXOv2CdP6qCVJO4wSyKtYfwMkZLL46zsbs1ySaaXJNZRYlIwjT8JlLiYc/UjmtqWGw2iCwBL2hGIoUyS/YxxtrhS+IDcyS83LymNEVTcoqtLzl6GoT8fAJMGL/OSE7fkaQ/Ja/1QeFXT+nIR97Hu7X3N3KmajJKiUjs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714474647; c=relaxed/simple; bh=q6OaaWp0CpFGoDKuaDFaKOAafHsUfiBWnlC2LiOVyDo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PxFOwa2fSCarGdu0xvDlMZJM3Zak0x7+XLQmI/4KVXq2KXwkRntkj0KY6YF95h+eN+YyrzpCoTy9RW8stmI+WCf8uMn0rgyg6tcLI0qv+DHQYdA6DOdmoZ1zHgwbVWtcIB0EH03ewRMG2DSmNSBjs09ndUsCzDhnWoMv73cOJOY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dtlejw7e; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dtlejw7e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E0F2C2BBFC; Tue, 30 Apr 2024 10:57:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714474647; bh=q6OaaWp0CpFGoDKuaDFaKOAafHsUfiBWnlC2LiOVyDo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dtlejw7euxvN6hpJ2n3w///1aTi7Gj5WGnQDwV488VQSlMDyB8vCmSL4jaZrIIhgG CjXmIjgCII42N+uD48uRUWY9g4Q9MKGuRR689tSNFpq+9Iw+3l31KgPv2Y8PYWkE5k kL+2V8ffHlCpMAoUkb5m81ZFF+tLXoA6ww1lL2ug= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tianchen Ding , "Peter Zijlstra (Intel)" , Abel Wu , Sasha Levin Subject: [PATCH 6.8 219/228] sched/eevdf: Fix miscalculation in reweight_entity() when se is not curr Date: Tue, 30 Apr 2024 12:39:57 +0200 Message-ID: <20240430103110.123420497@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240430103103.806426847@linuxfoundation.org> References: <20240430103103.806426847@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tianchen Ding [ Upstream commit afae8002b4fd3560c8f5f1567f3c3202c30a70fa ] reweight_eevdf() only keeps V unchanged inside itself. When se != cfs_rq->curr, it would be dequeued from rb tree first. So that V is changed and the result is wrong. Pass the original V to reweight_eevdf() to fix this issue. Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight") Signed-off-by: Tianchen Ding [peterz: flip if() condition for clarity] Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Abel Wu Link: https://lkml.kernel.org/r/20240306022133.81008-3-dtcccc@linux.alibaba.com Signed-off-by: Sasha Levin --- kernel/sched/fair.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 69d2158873429..b9ee4397b484a 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3670,11 +3670,10 @@ static inline void dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { } #endif -static void reweight_eevdf(struct cfs_rq *cfs_rq, struct sched_entity *se, +static void reweight_eevdf(struct sched_entity *se, u64 avruntime, unsigned long weight) { unsigned long old_weight = se->load.weight; - u64 avruntime = avg_vruntime(cfs_rq); s64 vlag, vslice; /* @@ -3781,24 +3780,26 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, unsigned long weight) { bool curr = cfs_rq->curr == se; + u64 avruntime; if (se->on_rq) { /* commit outstanding execution time */ update_curr(cfs_rq); + avruntime = avg_vruntime(cfs_rq); if (!curr) __dequeue_entity(cfs_rq, se); update_load_sub(&cfs_rq->load, se->load.weight); } dequeue_load_avg(cfs_rq, se); - if (!se->on_rq) { + if (se->on_rq) { + reweight_eevdf(se, avruntime, weight); + } else { /* * Because we keep se->vlag = V - v_i, while: lag_i = w_i*(V - v_i), * we need to scale se->vlag when w_i changes. */ se->vlag = div_s64(se->vlag * se->load.weight, weight); - } else { - reweight_eevdf(cfs_rq, se, weight); } update_load_set(&se->load, weight); -- 2.43.0