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 81ABE78B4E for ; Sun, 28 Jul 2024 21:18:52 +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=1722201532; cv=none; b=P4Uh2qh44m72Yrbk5qt4kBXAQtSjmtFx/zTkLWgx1XIFgNOlrEfkOQN7C90+xYL57DoslTzVAkJWnJ+qsgE8aDCWQuphWeW8YWqCuWYWAM8lo+0jBsgwGMgvQ+YSYy2Ry1sw3Eo8ooBhoEkPGeqBzbFaLPL7bnJ71ElOQOFQHx0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722201532; c=relaxed/simple; bh=p6ipjOvVqF6sbK1Vn/wHSaHvySBYHhkhbaqXeUP2Q04=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=rnIjyIvu9J6iStHQSwpH1WTrYkbGPWgjW8fawBB3q2HKe3oEzbueBCb6+Ki9FGkE6eV87OiVP9/Js8M3+6Pew5jDDSMtS5NlfAt/WTwO4ih03R9n0uyOL2Yh3xsvEBNf+8vPWUy7/FNc67+j0y2vLA9qUZa/SjvvDLe+G5axOmY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=LHAyydsJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="LHAyydsJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A9CF4C4AF0A; Sun, 28 Jul 2024 21:18:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1722201532; bh=p6ipjOvVqF6sbK1Vn/wHSaHvySBYHhkhbaqXeUP2Q04=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LHAyydsJalWoIjxDSMRu97+wFnQ1QVowDjGpa2JbcKo1Gq+JQNt9koZYp5n6dSXCv w5o6M2ftH42gXMsygOgd0M89g1rbIE8/+eDkBQHxceQF+QrlDFwxLrtHuj3rhmCxjm AnHuEU1nA/FAV246WRA/MApyVW/lqsNZiEPQfCJk= Date: Sun, 28 Jul 2024 14:18:51 -0700 From: Andrew Morton To: Adrian Huang Cc: Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Uladzislau Rezki , Christoph Hellwig , Baoquan He , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Adrian Huang , Jiwei Sun Subject: Re: [PATCH 1/1] mm/vmalloc: Combine all TLB flush operations of KASAN shadow virtual address into one operation Message-Id: <20240728141851.aece5581f6e13fb6d6280bc4@linux-foundation.org> In-Reply-To: <20240726165246.31326-1-ahuang12@lenovo.com> References: <20240726165246.31326-1-ahuang12@lenovo.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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-Transfer-Encoding: 7bit On Sat, 27 Jul 2024 00:52:46 +0800 Adrian Huang wrote: > From: Adrian Huang > > When compiling kernel source 'make -j $(nproc)' with the up-and-running > KASAN-enabled kernel on a 256-core machine, the following soft lockup > is shown: > > ... > > # CPU DURATION FUNCTION CALLS > # | | | | | | | > 76) $ 50412985 us | } /* __purge_vmap_area_lazy */ > > ... > > # CPU DURATION FUNCTION CALLS > # | | | | | | | > 23) $ 1074942 us | } /* __purge_vmap_area_lazy */ > 23) $ 1074950 us | } /* drain_vmap_area_work */ > > The worst execution time of drain_vmap_area_work() is about 1 second. Cool, thanks. But that's still pretty dreadful and I bet there are other workloads which will trigger the lockup detector in this path? (And "avoiding lockup detector warnings" isn't the objective here - the detector is merely a tool for identifying issues)