From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 D99AB1E5711 for ; Thu, 10 Apr 2025 15:32:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744299130; cv=none; b=CDF6ZMviQxVnUlOlw45Ps7ZPjhE/4QlJIfwfrRVk7zLZmQwqBg+UnOOI5EFHA1HpsPgEmlNZr9h6uK9mn2g1yPja2pPPD16HCOD4IPVc40fN98ZJklP6LYaFRe1hV83QbWPyWJPxf7s62le+3qS62GxWIYQZjMqxvhKEV06y0wk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744299130; c=relaxed/simple; bh=gxdJcCJ/gmxFhPUHphCiTz7Q1fy1LpjwDoMAC34A6rA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qRZ3u+HW2aVhtHizffTwC/bUhFLWZxzgWCghrVXcDBfCXIpSSRLRHSzPq8YZu8PLZ2MLqZHdlFxD/JiHS1pmY6NOTT6zAoyYHKSN4kkwN4b5HG3KJVG1iWjg6AWsyp0b9NiH9kY6oC3EgBaBxsdfJhRNnFFtyK188s6ml3iEs6c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=45tnEOjv; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=iD7s6FRu; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="45tnEOjv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="iD7s6FRu" Date: Thu, 10 Apr 2025 17:32:05 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1744299127; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JXnaW/57HWHmskd8RUZVPy85ulCSYuK64zuk6RecFgQ=; b=45tnEOjvTDE1O9dDasSGHedjb7mnAMkvaJBjYfio31r1HY7YvFEJlP+BpNfVkBRj0o3wER CHmljNQDa0wPGtUWBtVn4964e27Tq8CUQ+x9B6s5DQ1FJQN47SXRx2H1U8CteoZIvjKHwr C7o1thKgoMFW/+BJ1v76UneQvqkv3D2Hgcydg0zj4B8km6/Mh/DlLl/6z6SP+OVR/DaRzA kmGKPlNTb7amqUvTzX+7WerfK6BzVaLzI88zqtTc/xi5Q6PA9oT1vxQOzLxY+pXbBrIwfM Y1bgLxHnX4Uoq3rad2eKKxsIDqRJUJyqzxVn3VFFoD8kUN2fO2nZxoxvwvzkuA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1744299127; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JXnaW/57HWHmskd8RUZVPy85ulCSYuK64zuk6RecFgQ=; b=iD7s6FRuajNbUf7o1wCtmtr0TPf75IyFFYqBB+ZQl5ba+QAZenJA+Liyok5cErMXOhQSl+ dx+ouDdCS9LwQCAw== From: Sebastian Andrzej Siewior To: Peter Zijlstra Cc: "Luis Claudio R. Goncalves" , Clark Williams , Steven Rostedt , Tejun Heo , David Vernet , Barret Rhoden , Josh Don , Crystal Wood , linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, Juri Lelli , lclaudio00@gmail.com, Ben Segall , Dietmar Eggemann , Ingo Molnar , Mel Gorman , Valentin Schneider , Vincent Guittot , Thomas Gleixner Subject: Re: [PATCH v2] sched: do not call __put_task_struct() on rt if pi_blocked_on is set Message-ID: <20250410153205.u92eJDos@linutronix.de> References: <20250410064844.wm4KbunL@linutronix.de> <20250410075103.GV9833@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250410075103.GV9833@noisy.programming.kicks-ass.net> On 2025-04-10 09:51:03 [+0200], Peter Zijlstra wrote: > > I complained about this special RT case in put_task_struct() when it was > > first got introduced. Couldn't we just just unconditionally do the RCU > > put? > > Yeah, please make it simpler, not more complex. Just so we clear: simpler as in everyone does call_rcu() or RT does always call_rcu() and everyone else __put_task_struct()? I mean we would end up with one call chain I am just not sure how expensive it gets for !RT. Sebastian