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 B950D236A73 for ; Thu, 10 Jul 2025 03:48:10 +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=1752119292; cv=none; b=ZHjr7zjc3juF/AT/fvYJi0bAgWWdChlSoq60jbgQ/eVWNC1oiKUaeocfpcUf1E5UA56sNehnxgcCzBB6JbetsVVwaCxd5YLKwY0JGlR90qKH/Z30ZNZU4JurdQgcMj29GaXCcTvGCpdrfcd2q+7hvfzOqJKgs9JUPXNqLhpyWbw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752119292; c=relaxed/simple; bh=BdFbONTtnjgKbs64vRH2l6lz4Ut6wcLqB7fwFQKl1Ho=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=c5m3EvaFFrmdyUa8WH1ZI0pXGQJ6nQMJnpdo/ABCmSpOIYxvYC+lPRdqfqDX1q4pTFklFpKc3Xi0YeaEjQaeJbSr4xASa/Ctadco0jbMOMjT/4+S1Br1r6W+idXbDRnkn2xg9WAEDphQWK7GeTPy1L19vVWjtpMYxhBshhEFVUE= 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=MnXMuC4E; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=hcs0nt/T; 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="MnXMuC4E"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="hcs0nt/T" Date: Thu, 10 Jul 2025 05:48:05 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1752119288; 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=v+sY3z68x9Bwu1dqm+DwYPuEvGjqzY4XAcSPOiZPvco=; b=MnXMuC4EAiBfQMq8CwjHkUGGGvoPYzhSWHmrhcGsGDzgm8nGB/uFkYBMr+4N3AUA3D7qdt AgpV2t90ec1ROHqquWH67b+Eb44RuqqSzakZO9VXyqGwkYoueeCCgFVJ4dpvsksqEuxOW5 hHF1lCrlKVwdmKLA0KByVrNx+rCP6Xofl9v70xLTCt8CdF8MGSNGG2jKB/7uoTkkUI3WhN YdrliYK6l4cjZKcp91INRnvGqWxftovtwQYyYITxt7Ofo7XFZTREejRwCzPMlyQUT1foGI 1Hox+i62o2eIK/BnFtZp2foj/UHYE2F0+2txY0AO9FwydwSIXPLEPbCn/k6S0Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1752119288; 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=v+sY3z68x9Bwu1dqm+DwYPuEvGjqzY4XAcSPOiZPvco=; b=hcs0nt/TAZ+fhP2MHYXNzg/YPBBxVyBLfFRN+RcoixPpiBY44Y4XYxcN4WaSHXZ9LnpZ3G qLBkZwkDIGuamCAw== From: Nam Cao To: Xi Ruoyao Cc: Christian Brauner , Frederic Weisbecker , Valentin Schneider , Alexander Viro , Jan Kara , Sebastian Andrzej Siewior , John Ogness , Clark Williams , Steven Rostedt , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, linux-rt-users@vger.kernel.org, Joe Damato , Martin Karsten , Jens Axboe Subject: Re: [PATCH v3] eventpoll: Fix priority inversion problem Message-ID: <20250710034805.4FtG7AHC@linutronix.de> References: <20250527090836.1290532-1-namcao@linutronix.de> <20250701-wochen-bespannt-33e745d23ff6@brauner> 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=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Jul 10, 2025 at 11:08:18AM +0800, Xi Ruoyao wrote: > After upgrading my kernel to the recent mainline I've encountered some > stability issue, like: > > - When GDM started gnome-shell, the screen often froze and the only > thing I could do was to switch into a VT and reboot. > - Sometimes gnome-shell started "fine" but then starting an application > (like gnome-console) needed to wait for about a minute. > - Sometimes the system shutdown process hangs waiting for a service to > stop. > - Rarely the system boot process hangs for no obvious reason. > > Most strangely in all the cases there are nothing alarming in dmesg or > system journal. > > I'm unsure if this is the culprit but I'm almost sure it's the trigger. > Maybe there's some race condition in my userspace that the priority > inversion had happened to hide... but anyway reverting this patch > seemed to "fix" the issue. > > Any thoughts or pointers to diagnose further? No immediate idea, sorry. May I know your exact setup (distro version etc.)? I will attempt to reproduce the issue. Best regards, Nam