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 72275155C82; Tue, 26 May 2026 12:46:11 +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=1779799575; cv=none; b=gCeFocYeMO7cFOsvdxShbCQ9iK0olxrYkEQoI3Shg1wzq6hBrjx24T69y0F0XwY5A4uxzDrjbM81ir+Ok4ySyEshHQmIn4VcomxfJH7Y0MHk4JtTD3XXZPw9iCFHl0kZ79LaVCEPT5Kg3dc8rFeB238lm4bt296Pc6ANPYjaBXc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779799575; c=relaxed/simple; bh=U4Xzy5I1tp3zXSneLh4gKr+RJFv0GfIKo3Dm/LmTU28=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TRFfr/WU3O2yyHpfSuT7gQxoDxjZWZi9IwZw+QpWVU3joSSprnoGETX3EF0QX+Am+C8dIs60cWefLJk19mIx2IT0wO53qauiFEWUI2iilh58u3DsuyNaBlUZO9zvY5Mhic0JB/DM83YMqSHwUhRfSEQLZZULI/DS8gSbKJ5CGtg= 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=fCm1vazp; 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="fCm1vazp" 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=rkgWCF29mR6MYm02fUHtiVL/nxLhy0FulB0I8BQLvz4=; b=fCm1vazprDjxmazoOQ1ab+SiM+ T7pWjDExompMsjslBW/ptyGKZYpsd3ostYltnRCwCsiDvQlRwinFop4B0kNye0uPlP4MC5hIc8hRZ 1CC5dnCXabtHF5JZwUj/072VocFyJEaI93A08j6F6486TJdyk7jzbzbQkllElvjjfDPP1EAF5EYL7 TD68P6NKrJAzE2Oup/gdmGf+WoNodGzMQOA7dnRfYpzPKaK3j4pjmi04S364YAWSDZDxyWlRVP+2e mOjfeILeMv6cxdkABuMtZnPJR6XIAJcgWsS/QJhRv4Ap7dsVsEJwJ+9BvXBYtWaKhofOUJHGj6cL8 CQZt/W4A==; 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 4.99.1 #2 (Red Hat Linux)) id 1wRr5W-000000013NZ-0Vs3; Tue, 26 May 2026 12:40:50 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 7D234300323; Tue, 26 May 2026 14:40:48 +0200 (CEST) Date: Tue, 26 May 2026 14:40:48 +0200 From: Peter Zijlstra To: K Prateek Nayak Cc: Zhang Qiao , mingo@kernel.org, longman@redhat.com, chenridong@huaweicloud.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, tj@kernel.org, hannes@cmpxchg.org, mkoutny@suse.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, jstultz@google.com, qyousef@layalina.io, Hui Tang Subject: Re: [PATCH v2 10/10] sched/eevdf: Move to a single runqueue Message-ID: <20260526124048.GV3102924@noisy.programming.kicks-ass.net> References: <20260511113104.563854162@infradead.org> <20260511120628.206700041@infradead.org> <85116808-8643-47d7-b4e7-2a11c3999b20@amd.com> <20260526095210.GC4149641@noisy.programming.kicks-ass.net> <3f1fc681-a73b-4bd2-9a6a-e61b8fbd5826@amd.com> <20260526110709.GF4149641@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: <20260526110709.GF4149641@noisy.programming.kicks-ass.net> On Tue, May 26, 2026 at 01:07:09PM +0200, Peter Zijlstra wrote: > On Tue, May 26, 2026 at 04:24:32PM +0530, K Prateek Nayak wrote: > > Hello Peter, > > > > On 5/26/2026 3:22 PM, Peter Zijlstra wrote: > > > On Tue, May 26, 2026 at 02:45:45PM +0530, K Prateek Nayak wrote: > > > > > >> The suggested diff above solves the crash in my case but your > > >> mileage may vary. Peter can comment if this is the right thing > > >> to do or not :-) > > > > > > Is this a different issue than the one you raised before? > > > > Yes, this is different. Essentially, this is what is happening: > > > > throttle_cfs_rq_work() > > task_rq_lock() > > > > dequeue_task_fair(current) /* Task is dequeued on cfs side */ > > __dequeue_task(current) > > dequeue_hierarchy(current); > > current->se.on_rq = 0; > > /* update_load_sub() */ > > resched_curr(); /* Initiates a resched */ > > > > task_rq_unlock() > > local_irq_enable(); > > > > =====> sched_tick() > > task_tick_fair() > > __calc_prop_weight() > > /* > > * Oops: update_load_sub() above has > > * 0ed the weight of cfs_rq. > > */ > > <==== > > > > preempt_schedule_irq() > > next = ... > > put_prev_set_next_task() /* The runtime context is switched here */ > > > > Ah, right. OK, I'll go have a poke once I get these proxy patches I've > been spending too much time on posted. Yes, your solution seems reasonable. I'll fold that and push out a new version a little later today.