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 D4DBD23ABA0 for ; Mon, 15 Sep 2025 15:31:54 +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=1757950316; cv=none; b=j57YixvRGSHoZ2RyU6Yxfqc1KQeCA4nLDCMEccGP17e4Eor2EmmAqj56xSK1fOzcPL2OexdNerR04rKG0XC1L/hnDpalnroyvu0eUrQ3F9C19KSpEyYLkJUrH/A33LX2tIntiMBM+K2WHJPAercPL8Tj6RtpBGGH0hTqawvS4+4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757950316; c=relaxed/simple; bh=iFihoKHZq4DfQWQgGJvrxJfcyMRoyDvnvVIvIAiilFI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cMg2K2xs/ka43ixu3cZQtEwOzIKbUspis9XQ3l/IN6qjNhp60YBtbqLztOECoeWLC4jwFHx/bDZWIZroSiWUqOxArZqU2NDuPrJDX07E2Mh+PVX3mcPbFO9NzO7k9kSTzf8ZlWY0Ocob0GWG+rwFmVVnN5Dkb6S6iAFHdtrzlVs= 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=RiNhsm8j; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=1ULRprKS; 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="RiNhsm8j"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="1ULRprKS" Date: Mon, 15 Sep 2025 17:31:51 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1757950312; 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=16BPyb79WnSLgcLqvDIXMPPG6yOIETfT08w7CMnijGM=; b=RiNhsm8jJ8rTarD0TPzxSlAxgSDixb0CZN/qNT1ZY+1b/PxmeRiPMalH+zxejmCafjWkNq LWAZWZRWDqJyFhXtXbvvEYgWrBkuo+gj2NLI224Cnnnql5wwyAF5nH0Y1QPfKibqXn7wVH yZUcjMzbIZ97/xF789KG3UodW8CUaPUrAFfaNNsIW5ShRwCpeuZ3vfHHct+HAr6YX87xXp iWXG4c6h7Uzmz9mQnE5r23+xJiETe8GmSG60IBt5OPFPvEDS5BxiIAHBymKJjm2+pcWtiH p9bifu3hsplNiaHAxed7fFNCbub3JHwWHgYL0XVkB8Ktn2KUKo2Ua9V9Eu19JQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1757950312; 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=16BPyb79WnSLgcLqvDIXMPPG6yOIETfT08w7CMnijGM=; b=1ULRprKSedyefkPqzebhK+AoHbxwXKUOdMaIh4bSlrgObXlqoigoeVG20IbOyBpaCREjxq s8AsX8YmxFFenxDQ== From: Sebastian Andrzej Siewior To: "Luis Claudio R. Goncalves" Cc: Peter Zijlstra , Oleg Nesterov , 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 , Ben Segall , Dietmar Eggemann , Ingo Molnar , Mel Gorman , Valentin Schneider , Vincent Guittot , Thomas Gleixner , Wander Lairson Costa Subject: Re: [RESEND PATCH] sched: restore the behavior of put_task_struct() for non-rt Message-ID: <20250915153151.fPHJU6-d@linutronix.de> References: <20250915113812.GB3245006@noisy.programming.kicks-ass.net> <20250915122444.Gg_Tsymz@linutronix.de> 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 In-Reply-To: On 2025-09-15 11:49:37 [-0300], Luis Claudio R. Goncalves wrote: > On Mon, Sep 15, 2025 at 02:24:44PM +0200, Sebastian Andrzej Siewior wrote: > > On 2025-09-15 13:38:12 [+0200], Peter Zijlstra wrote: > > > Right, but I thought we did want to make this behaviour consistent. > > > > That is correct, that is what I asked for (either consistent or a > > compelling reason why not). > > I received a ping from colleagues investigating a problem possible caused > by excessive pressure on RCU and this change could make the problem worse. > But last I heard from them, sounds like the problem they are investigating > lies elsewhere. Either way, if this change introduces a problem then it affects RT as today. So we should deal with this. If it is not a problem and it just put pressure on an existing problem then it shouldn't be an issue. > Luis Sebastian