From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 9E14A19F137; Fri, 19 Dec 2025 23:37:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766187476; cv=none; b=bwFXYX1LQ2XWqoeEecJj7TTe4yBE4V+PeXB40rhXLzjYnLkVUM+x50VVPYeDDJLxeSzuX1h2esDS3bH73w4F7QeAnAfEeOeMcAX/y1cea7clMzoIkM9PQkOBAJ0DvXR3BY4GdmetUbonD6rll9HiF4JJdqt00t2Zxa+ge90av38= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766187476; c=relaxed/simple; bh=a2mE4kTYj24K4sJLZJUc/P6K7hmjoaPpH/iReic98Mg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VDbHOZvUObetLDQuFKJNQNJINC7Fxdp/S6lwudYt2ssWnxkPJegAjxTGcnGd0voCQ3/lyz1gBVs9UR3qyo023NpPl3MbprpsU0k68VxeEDUl+tmbV9usOVBA6GSZKdBCytjlAEnUnBQoBW0X/QanbwKiFJ6jNtg6w87Ak5QBrDY= 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=ooGrO/n+; arc=none smtp.client-ip=90.155.50.34 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="ooGrO/n+" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=7iDiFa9C6BbQmq3eA90hwy/boYCk4vo9zcd1KlfWLIg=; b=ooGrO/n+PKzaq+plXioglWkC5B f0enapG8j3yHDRAH/dXfpWR92EkbWh/zKrKUI3itCreuFQhjay6EbjHMGRDlCbqk1m4fMAm+qec96 MsDQon4BD32uHjjhXV1HgZN/TCDLSCDnIdIyzjJXsxx8IG5fX74Y7NQX+WzW2cNOrdHYdDKJjrSNT +jwmKsfrfve+jyGRqIeMdI5khflMH67fBlNHQXXtkpTRU8jbzlcGJCYMs3aby7Q85lLknTf/yzDvZ Ku4RC2HFpriodsYWXOMIOmx0sCX7XI240JFlw8vAmYVoHJSatdbZQ/6wnya+fe2k54TMFyVWJW8lu cZFd6qvQ==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vWk2e-00000008JKw-0QQW; Fri, 19 Dec 2025 23:37:48 +0000 Date: Fri, 19 Dec 2025 23:37:47 +0000 From: Matthew Wilcox To: kernel test robot Cc: Vishal Moola , oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, Andrew Morton , Uladzislau Rezki , linux-mm@kvack.org, Mel Gorman , Vlastimil Babka Subject: Re: [linus:master] [mm/vmalloc] a061578043: BUG:spinlock_trylock_failure_on_UP_on_CPU Message-ID: References: <202512101320.e2f2dd6f-lkp@intel.com> 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=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Dec 19, 2025 at 08:26:14PM +0000, Matthew Wilcox wrote: > Now, as I recall, we are very much doing this on purpose. We decided > not to disable interrupts at this point for improved interrupt > latency, accepting the possibility that we'd occasionally fail > the trylock. Except on UP that's now an assertion failure. This is stupid and wrong. If we have CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=n, then trylock always succeeds. And we'll end up corrupting the data structure protected by the lock. So the warning is real, and we need to fix this. With my distro hat on, I do not give two hoots. We don't ship a nosmp kernel. I suspect all other distros (except maybe something targetting m68k?) are in the same boat.