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 536A4487BF for ; Mon, 24 Feb 2025 21:33:06 +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=1740432787; cv=none; b=gasWQWK+5o2N3otRQnimcBeLrN8DyckyxMzmTzdqFpn+O5VlJRW8GWxpeWnH8/opyWHyXz95DENn2zfJKzG80Fw66u0f7eB1/hPFDH/j5W0IYQshmZ4UBXFE144VPLLfF29tMsP6GhBB/mZcJJlLklYFxApYluC6X+fMaRec/ww= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740432787; c=relaxed/simple; bh=7j1F3muHSUrWVZJJa38ApN+toUwQgOmPJryKHmXJWtE=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ah+tUm5VwiJm3OfvvO7u7F01If9INXECygjD7Ks+I4V+2lpibRqfTjZj0ImxAHGf78pmNDjgamD8aCiausIWHgwBwo1o9Jzz9JrNoe+xv/+Dh08v8F8Vfn0PlIl/srHU3WyzmjT4Y2kM2NxHx6wXPx4a57+imbr4LvnTBmBjUl8= 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=wTiQ0h/K; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=fH3pVqn1; 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="wTiQ0h/K"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="fH3pVqn1" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1740432784; 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=tWDoE5CbBA5B9bltSD4gKawYB98PjhAjPtq+O+D3AF4=; b=wTiQ0h/KLAHCKY3bebjJklkwG2TC13sofiuEsZO2I9s3ljFEoQ33aVEI0rbINt1qycJU+n WS/zxTfh1/qpuyaRDOve3AemkToo2NE+2eEQdA6zfEmI72HloWUCRUIiW7pDlkH7lmNXvE AoLIqZuslrsuIhoAEIxFPr4pfQ+UJXJyu89THUSjWaWRnbvF0UnwFSqkyXy57ZpCwJH7ap fT+7r9MWjbntMsiDL1yJElEu6DeACa4e5bzq4mrw59WEWHvyXYKYm7avdERqOiehJ/X5XD q2RVhgw7z11LKvyzrYNoRJLFiKzG+v7D3X7R6kQh1aqNOhM76mRlRZ8N0vY2uQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1740432784; 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=tWDoE5CbBA5B9bltSD4gKawYB98PjhAjPtq+O+D3AF4=; b=fH3pVqn1HLyl/y/xA8FI7olvMyBzVmvVQv41B59lqgY9Zve4AkdIJI/mEXBgGPbv3kt4ES JlrdCsabTLGH57BQ== To: paulmck@kernel.org, Christian Heusel Cc: Rik van Riel , Neeraj Upadhyay , Ingo Molnar , Zqiang , Thorsten Blum , Mathieu Desnoyers , linux-kernel@vger.kernel.org, regressions@lists.linux.dev Subject: Re: Warning/trace in kernel/smp.c:815 smp_call_function_many_cond In-Reply-To: <99c7bdb6-76e3-42ce-9a0d-c5b72a2c132a@paulmck-laptop> References: <46a200b4-1293-413c-8b73-37f7b50abd1a@heusel.eu> <99c7bdb6-76e3-42ce-9a0d-c5b72a2c132a@paulmck-laptop> Date: Mon, 24 Feb 2025 22:33:03 +0100 Message-ID: <87jz9ff2pc.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Mon, Feb 24 2025 at 06:57, Paul E. McKenney wrote: > On Mon, Feb 24, 2025 at 02:57:40PM +0100, Christian Heusel wrote: >> Hello everyone, >> >> I have noticed the following new warning in my dmesg output, I think I >> have first seen this when upgrading to v6.14-rc1. >> >> So far I have been unsuccessfull in bisecting it, therefore it would be >> nice to get some input whether this is something serious or how I could >> debug it further. I have also attached a full dmesg for more context. >> >> ------------[ cut here ]------------ >> WARNING: CPU: 3 PID: 0 at kernel/smp.c:815 smp_call_function_many_cond+0x46b/0x4c0 > > This happens when something invokes one of the smp_call_function() > APIs not in task context, that is, if it is called from NMI, hard IRQ, > or soft IRQ contexts. > > Which it is in this case, due to clocksource_watchdog() being invoked > from a timer handler. This only matters if the clocksource is being > marked unstable, which is what you are seeing. > > One possible fix is to move the call to cs->mark_unstable(cs) from > __clocksource_unstable() to clocksource_watchdog_work(). This would > require marking the clocksource so that clocksource_watchdog_work() > could find it. > > But is there a better way? That's fine and should be trivial to do. This business is asynchronous anyway, so it does not matter much when the unstable call is a bit delayed. Thanks, tglx