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 3BC36421EFD for ; Tue, 31 Mar 2026 16:15:00 +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=1774973704; cv=none; b=qcdmdRgzgSU5lR9i/Va/vvrVpqQ9MAVbrkX2xkXxoDMqXYtX1B1GmKnesYZ5sF4k0f50VwEzVPCqeG7bd11r/AaLbvLbvBj7H6i/MERvuMimQ9EnRBosG4uwRqmAbLSlB+AsJyA81uAB8NYzKMDFeMi7eFA4NuTE/Ntce0xNfTM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774973704; c=relaxed/simple; bh=VFdwr+AWcqsBqEcQ1I7N4NBbAzVpAnlt4abGT7GgIJw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=P6QbyDMpR3xEAXmX8gtaxrRfdyBr/ZRfXH2PIGYuA6tLHkDBSEQ9Gkvl1HlFcpVc+0cFnBo3vey1xFCgSl+bOTAz7PXhCOcWiyPGc0pNr8l2ujONj7TNV3RUpTD6JHEWhHLyB09fpk/S2n5HSXeUC3rG8Uf7v2cMfoJKT6UzBPQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=jJCD1wpX; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="jJCD1wpX" 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=Keg46EcvsfP/tynn7OZuYvDVV1GFQkMefh0QMF1Ow9g=; b=jJCD1wpXx/I9Z1DOoecdlfdIGh frOigDs190JXjKOVFW/RFhVzEow3VDreXVHJLsin1kB4TIxjv09wSNlSbQgHBozJc9csshL2EfgaI 0eh7hx3JaHOC65t4JaUO61sbQ+ba9LpXdWUqEd9NcAPp5ipKEGaOb8ddWun/nDWW6sAFZrSOD3gSf Xmwuap+ixlw1OIckkCWlxBWATNLm+lGzoZ/HwW1tiQe+Kh/MOO8ntkOYMV91Q6IQ/1g0EAfDkv9ar D3Jh9sk35c2ATsIqbWlDxXav3Eesk3cJ2t5njA+LhiOqe56U2mw2mZlPIHZKJ5WbrIkHJjb8a5rvI lbS/ZTLA==; Received: from 2001-1c00-8d85-4b00-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:4b00:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1w7bjo-00000008o2G-2aqp; Tue, 31 Mar 2026 16:14:44 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 2BE02301185; Tue, 31 Mar 2026 18:14:43 +0200 (CEST) Date: Tue, 31 Mar 2026 18:14:43 +0200 From: Peter Zijlstra To: K Prateek Nayak Cc: John Stultz , mingo@kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org, wangtao554@huawei.com, quzicheng@huawei.com, dsmythies@telus.net, shubhang@os.amperecomputing.com, Suleiman Souhlal Subject: Re: [PATCH v2 1/7] sched/fair: Fix zero_vruntime tracking Message-ID: <20260331161443.GA134305@noisy.programming.kicks-ass.net> References: <73dab51a-650f-4c82-9e73-13236b2a26c2@amd.com> <20260330144005.GP3738786@noisy.programming.kicks-ass.net> <20260330191108.GU2872@noisy.programming.kicks-ass.net> <20260331070822.GC3739027@noisy.programming.kicks-ass.net> <20260331071402.GN3739106@noisy.programming.kicks-ass.net> <19667aac-99c4-40cf-bc0a-b1e6b9d32ede@amd.com> <20260331092909.GQ3738010@noisy.programming.kicks-ass.net> <20260331122035.GO3739106@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260331122035.GO3739106@noisy.programming.kicks-ass.net> On Tue, Mar 31, 2026 at 02:20:35PM +0200, Peter Zijlstra wrote: > WTF!?! I'm thinking this might help... I'll try once I'm back home again. diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index b24f40f05019..15bf45b6f912 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -902,6 +902,7 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) { s64 left_vruntime = -1, zero_vruntime, right_vruntime = -1, left_deadline = -1, spread; + u64 avruntime; struct sched_entity *last, *first, *root; struct rq *rq = cpu_rq(cpu); unsigned long flags; @@ -925,6 +926,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) if (last) right_vruntime = last->vruntime; zero_vruntime = cfs_rq->zero_vruntime; + avruntime = avg_vruntime(cfs_rq); raw_spin_rq_unlock_irqrestore(rq, flags); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "left_deadline", @@ -934,7 +936,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "zero_vruntime", SPLIT_NS(zero_vruntime)); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "avg_vruntime", - SPLIT_NS(avg_vruntime(cfs_rq))); + SPLIT_NS(avruntime)); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "right_vruntime", SPLIT_NS(right_vruntime)); spread = right_vruntime - left_vruntime;