From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 BC07C35E1D3 for ; Wed, 27 May 2026 08:59:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779872373; cv=none; b=DfhaDvR8QV5YSiJBsR8rSfVbSF/OXl5dT2E+zQrA3tAF2aA+Px798SYw/BMphv6Ag895bRVp6y3V6RbKoM4J2ZbgS0r1Vej2oIkphtylDp6BuQRtd+jKPgXtBOp9tmb81ZXTPQDdhcoEcTmpkaFXd23v7RgniMgu3+Tu6C66ZYU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779872373; c=relaxed/simple; bh=iXb3RfRTwksV1D+bFobVtTi/lYuWuJJSehEEyj8NPXI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SwS7aYIeeWsUi5uSpLJFuDyt2cBwy0oyu5XmABkfHjVcJcWXdS+eqyzstlVuYEg5xihRw6jf374z/J0o44pUSN4HogfhE2mhyC/at+dShjG0k8j5DEB/oUlZfxIkw/+Cm1NkLyjxBLHltnlVV0EnafR+EloqGmWXZoHYu/xEook= 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=Mj2UQzBF; arc=none smtp.client-ip=90.155.92.199 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="Mj2UQzBF" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=7zg1+Fz66bN/R77jFY8cIo7vebRSyrkV1Mhw4ieji2g=; b=Mj2UQzBFfqGMEaDS9tzxKfwsc+ 3cL0oi+g2UazpjL/rXqtSKZdeeJWSb5deynywFk+97ewr/F7uWFGHu8dgjC4+tPlQiosTrk1rbwhx peGy3sxOlQJuTpxdy3HbWfZxID2K0IN54ROkfSVyXsUNEvP5f5NOo94Ah8bqNRwvcVxY11QqCoTCQ PEuM1034lssDTjrDQUB7Y9c/vpQ+A8z011Irk7i2Ko55yugA4cETzmRP0BvqlEistrWMvGZ81WCOs B+65a13M/5wEwiJvJcOLLUysX0PpgYmNnmBADvD6PeIfYZFUPs3R0aUQEnWgcEKvhTSlbJYXKYlAw m2kcSYdQ==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSA6Q-0000000DMXa-2upJ; Wed, 27 May 2026 08:59:03 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id AC19A300673; Wed, 27 May 2026 10:59:01 +0200 (CEST) Date: Wed, 27 May 2026 10:59:01 +0200 From: Peter Zijlstra To: John Stultz Cc: K Prateek Nayak , Joel Fernandes , Qais Yousef , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Valentin Schneider , Steven Rostedt , Ben Segall , Zimuzo Ezeozue , Will Deacon , Waiman Long , Boqun Feng , "Paul E. McKenney" , Metin Kaya , Xuewen Yan , Thomas Gleixner , Daniel Lezcano , Suleiman Souhlal , kuyo chang , hupu , linux-kernel@vger.kernel.org, Mike Galbraith Subject: Re: [PATCH 1/6] sched/proxy: Remove superfluous clear_task_blocked_in() Message-ID: <20260527085901.GR3126523@noisy.programming.kicks-ass.net> References: <20260526111609.433880331@infradead.org> <20260526113322.120970670@infradead.org> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, May 26, 2026 at 04:54:01PM -0700, John Stultz wrote: > On Tue, May 26, 2026 at 4:39 PM John Stultz wrote: > > On Tue, May 26, 2026 at 4:16 AM Peter Zijlstra wrote: > > > > > > Per the discussion here: > > > > > > https://lore.kernel.org/all/20260403112810.GG3738786@noisy.programming.kicks-ass.net/ > > > > > > The reason for this condition is that the signal condition in > > > try_to_block_task() would set_task_blocked_in_waking(). However, it no longer > > > does that, in fact, that path does clear_task_blocked_on(), rendering the > > > clause under discussion moot. > > > > > > Signed-off-by: Peter Zijlstra (Intel) > > > --- > > > kernel/sched/core.c | 3 --- > > > 1 file changed, 3 deletions(-) > > > > > > --- a/kernel/sched/core.c > > > +++ b/kernel/sched/core.c > > > @@ -7132,9 +7132,6 @@ static void __sched notrace __schedule(i > > > if (sched_proxy_exec()) { > > > struct task_struct *prev_donor = rq->donor; > > > > > > - if (!prev_state && prev->blocked_on) > > > - clear_task_blocked_on(prev, NULL); > > > - > > > rq_set_donor(rq, next); > > > next->blocked_donor = NULL; > > > if (unlikely(next->is_blocked && next->blocked_on)) { > > > > Oh good! I had a note to try to re-confirm if that chunk was really > > needed, as it did feel a bit like it was patching up a problem after > > the fact. > > > > That said, running this on top of your sched/proxy branch tripped over > > warnings with the ww_mutex selftest, so it looks like there's > > something else missing before this can land. > > > > Digging in, it looks like we still need the fix I had here: > > https://lore.kernel.org/lkml/20260430215103.2978955-3-jstultz@google.com/ Right, that patch looks reasonable, pulled that in. > I'll be doing some stress testing with the rest of set later, but so > far with the extra fix I pointed to this is looking ok > Acked-by: John Stultz Thanks!