From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 BF0BD235C01; Wed, 8 Oct 2025 13:58:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759931921; cv=none; b=AulX8vsVUvlvDt6FUWOY6ekak0csyCtpBoFROnjlWwRxsKrkacUAFE4ezGEtxfPjxgXIcpuBWY5+0IX+wKXa7uU7WU4q2brCsMf/IYsVO05/LZgRzNQMMYrAE2ko3RjuQ+kbksbXZnqtkkFOstysLyEolCNvpIFMLXzYh++SsD4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759931921; c=relaxed/simple; bh=bIS3CECsL9SwkAipfM5moGJaHurPrBbwODg4g5wtQHM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XJN1pqGDUlW1zyewzIOS7QOpwo3d9KLns7HGlb4IZGZXfVW21fAnFb92SLdEvpG8xD9hJV0RTJ5svUcC6XTf2D70Clxc1cIQdB5Blx0XBxjvPCkZhmJMSkTFajL3kAujhYSNox4djpz2ALuG+GXeS3efXEl2D6Gxa1Krt7yeISs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=SdaM1Ygh; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="SdaM1Ygh" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ipkIo97WbfBXRfA6Awwdt/Zt8vCBI383wL+H18F9oN8=; b=SdaM1Ygh/wofs08waEwgi2Ygfh aowIUPM0qhNBaW7nEsPjVFpsZLgqsDebSdN4+zgzNR51oTyD08eYfhgDK++m5T3vPg6V1off2CPYA HyIS+grnasQCBoViBmGQz/Lv5cOfikc8MYJ5jJ1JiBeXef4FJR4tuuqcl0OtOvdQJbaHo1iuv37iT cDw71CqJyI3IxwSe+PSwjV9uXMQM1o1QdumtEQQMoLcR1mcMbak4i/XhQ4ACOO3KLOTKAIXUS4Wtx wrjx+lMFVd+oTOiFa03/v8NCxYSgG7nlfMAF9xnJm4UIjK7bCFNp9yg5o7p/mNRSZm7cb6SSIfvdj Sve5RPZw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1v6UgY-00000006LBg-03HX; Wed, 08 Oct 2025 13:58:31 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id BBA19300400; Wed, 08 Oct 2025 15:58:30 +0200 (CEST) Date: Wed, 8 Oct 2025 15:58:30 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: tj@kernel.org, linux-kernel@vger.kernel.org, mingo@kernel.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, longman@redhat.com, hannes@cmpxchg.org, mkoutny@suse.com, void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, cgroups@vger.kernel.org, sched-ext@lists.linux.dev, liuwenfang@honor.com, tglx@linutronix.de, Joel Fernandes Subject: Re: [RFC][PATCH 2/3] sched: Add support to pick functions to take rf Message-ID: <20251008135830.GW4067720@noisy.programming.kicks-ass.net> References: <20251006104652.630431579@infradead.org> <20251006105453.648473106@infradead.org> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Oct 08, 2025 at 03:16:58PM +0200, Vincent Guittot wrote: > > +static struct task_struct * > > +fair_server_pick_task(struct sched_dl_entity *dl_se, struct rq_flags *rf) > > { > > - return pick_next_task_fair(rq, prev, NULL); > > The special case of a NULL rf pointer is used to skip > sched_balance_newidle() at the end of pick_next_task_fair() in the > pick_next_task() slo path when prev_balance has already it. This means > that it will be called twice if prev is not a fair task. Oh right. I suppose we can simply remove balance_fair. > While reviewing this series, I also noticed an older issue that we > have with check pelt lost idle time [1] > [1] https://lore.kernel.org/all/20251008131214.3759798-1-vincent.guittot@linaro.org/ Let me go have a look.