From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5B9D91DC9B4 for ; Tue, 18 Mar 2025 20:24:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742329492; cv=none; b=gNxjerS7bBAbJpgUp8OYDy2K3btGtPlm+Mq+xhosHI4AUDI9qCps1It4Se/ncGQrx1vImL85eeR5G3IQxXof6ObY3x9x6lmi98On9UDKBChfmoH/1J7YWbdmmF5ge0ZsKla74y/+tfI4BAYRfqKXHTI83fb187KfZFJU5k7nldU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742329492; c=relaxed/simple; bh=KY3HRdb15vZT/e5HPoX5e23ypHvo0iUY3vzHX2ls8P4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QpZkUub+HRsCW7UCGg1KVOUoCuE+XRsL0IiC410r0myl0Us9PpAhkMdODbHyMncAWwjvLz6slqZN+QtupvNsgnW5MXsopyeS6ya6un19w4Du2WQ3pQ2vCDfMImy069aashPP0UeSMYjTCUaJeTfpwlv65hLaajzHiIr2P++rDm4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WYZSwsia; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WYZSwsia" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 670E4C4CEDD; Tue, 18 Mar 2025 20:24:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742329491; bh=KY3HRdb15vZT/e5HPoX5e23ypHvo0iUY3vzHX2ls8P4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WYZSwsiakUtFFLP5mXsHmTaeKx5dpYYnpeuWFIUig5e8Hii8odR7KZ6Z0ji3WasgO 6PzlsXwJwPP5QJ6Yh+yg+s9ca4D7KajKRdqFyUbyb5ACzsI2LsZp92Koa+YWizGai9 w2eXcWcf78nG11e41sCViIKENjpEL0TS/i1D8gpQn4enXN4gIr3r0eMzwK5G1k8EpK oGsuHR+BJscJSVlsg3nMu18L8wtxGYH042+oP7OgALJKEXWic28IVJWF2z1ebufKSx BadoAjAHwNJ7waAm+DV3EfM9LVYT/ThmPF33Ku5t96Ud5gWfrtW+DWBN9Dxlp/SM8u qqAnqqRwvo68g== Date: Tue, 18 Mar 2025 21:24:46 +0100 From: Ingo Molnar To: Maksim Davydov Cc: x86@kernel.org, linux-kernel@vger.kernel.org, den-plotnikov@yandex-team.ru, gpiccoli@igalia.com, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, tglx@linutronix.de, hpa@zytor.com Subject: Re: [PATCH v5] x86/split_lock: fix delayed detection enabling Message-ID: References: <20250318144911.10455-1-davydov-max@yandex-team.ru> 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: <20250318144911.10455-1-davydov-max@yandex-team.ru> * Maksim Davydov wrote: > If the warn mode with disabled mitigation mode is used, then on each > CPU where the split lock occurred detection will be disabled in order to > make progress and delayed work will be scheduled, which then will enable > detection back. Now it turns out that all CPUs use one global delayed > work structure. This leads to the fact that if a split lock occurs on > several CPUs at the same time (within 2 jiffies), only one CPU will > schedule delayed work, but the rest will not. The return value of > schedule_delayed_work_on() would have shown this, but it is not checked > in the code. So we already merged the previous version into the locking tree ~10 days ago and it's all in -next already: c929d08df8be ("x86/split_lock: Fix the delayed detection logic") https://web.git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=c929d08df8bee855528b9d15b853c892c54e1eee Is there anything new in your -v5 patch, other than undoing all the changelog cleanups I did for the previous version? ;-) Thanks, Ingo