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 540CA1D14FC; Wed, 2 Oct 2024 14:07:39 +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=1727878059; cv=none; b=nUvkkN7/Bxqo1Oa9IyxLtn1mdPq6krlmULwu3JPcZTL/6rvSpejVuuYPXzMtCYUW8KA6YcT/JObSZ9dIyf+29Ancp3RhnPpbIZlUjGmmkSMI4opmyBodfyW0J3HGGwvnolAbwBF9CyzqZPXjt2HQN9DLwy/FhgOEXFoKzj7XbjY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727878059; c=relaxed/simple; bh=DRpOFf8cHz5io51K6nuzJ02XkyYu7QPibsbglYaZU1Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cVbjwm0F1QjugSASALaOLMAirtUqFsvK0jkmpRih7uuVf7aQyg3a0FoeeYkpxzgdUTLA9eIXXHeG4VroFUfyCCECbeCbHVt6Z9D+kOX+gk5CqglQzdzGOGSvEJEjeSb0tJEuTZGO7V/weHTesrQsvWigIXyvgL09HL8GWhUShfM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Cx2q+zG6; 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="Cx2q+zG6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C49CFC4CECD; Wed, 2 Oct 2024 14:07:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727878059; bh=DRpOFf8cHz5io51K6nuzJ02XkyYu7QPibsbglYaZU1Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cx2q+zG6wbdBiBTBXDFVncOvQZnY62yXrO2LlmXEqgaVQgofW3fUvr/NybTVI/CZM xUTKkRSAQGoCzBjY8/b/+SM8xyEN3xE4x43nbcw+6BlXg6vr+MWzhf3PFEOU0MDSoo OV/yMetweIx9xKYKhrN1pRDyKKULTATKex0CkW9Q= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chen Yu , "Peter Zijlstra (Intel)" , Hongyan Xia , Vincent Guittot , Sasha Levin Subject: [PATCH 6.10 287/634] sched/pelt: Use rq_clock_task() for hw_pressure Date: Wed, 2 Oct 2024 14:56:27 +0200 Message-ID: <20241002125822.438103473@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241002125811.070689334@linuxfoundation.org> References: <20241002125811.070689334@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chen Yu [ Upstream commit 84d265281d6cea65353fc24146280e0d86ac50cb ] commit 97450eb90965 ("sched/pelt: Remove shift of thermal clock") removed the decay_shift for hw_pressure. This commit uses the sched_clock_task() in sched_tick() while it replaces the sched_clock_task() with rq_clock_pelt() in __update_blocked_others(). This could bring inconsistence. One possible scenario I can think of is in ___update_load_sum(): u64 delta = now - sa->last_update_time 'now' could be calculated by rq_clock_pelt() from __update_blocked_others(), and last_update_time was calculated by rq_clock_task() previously from sched_tick(). Usually the former chases after the latter, it cause a very large 'delta' and brings unexpected behavior. Fixes: 97450eb90965 ("sched/pelt: Remove shift of thermal clock") Signed-off-by: Chen Yu Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Hongyan Xia Reviewed-by: Vincent Guittot Link: https://lkml.kernel.org/r/20240827112607.181206-1-yu.c.chen@intel.com Signed-off-by: Sasha Levin --- kernel/sched/fair.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 3c59f2b34a779..5e4162d02afc1 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9365,9 +9365,10 @@ static bool __update_blocked_others(struct rq *rq, bool *done) hw_pressure = arch_scale_hw_pressure(cpu_of(rq)); + /* hw_pressure doesn't care about invariance */ decayed = update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) | update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) | - update_hw_load_avg(now, rq, hw_pressure) | + update_hw_load_avg(rq_clock_task(rq), rq, hw_pressure) | update_irq_load_avg(rq, 0); if (others_have_blocked(rq)) -- 2.43.0