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 4544513D265; Tue, 26 Mar 2024 19:56:25 +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=1711482985; cv=none; b=PGnm1p1Cm0PWde67gR3DqwjQVqd2chYRHo6jgIFdi+OT92Zvgc6OpHvVSoQbieXhZnlhm2b4DDhJ1E9m/xQEGM5R8Xe6bNBpowrSfnGdIpeFyBhLycGkoagYmtXeRFc7zQERhb27Mvyl+a2wYfT+Du+odUzxMtgK0Yl0+vNpBA4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711482985; c=relaxed/simple; bh=x4np21dJ2uZ9vYBCKDq3W9rjAOMd4x0jIzHTs6BvC5k=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=pDARxrkmK3tHaZjp85LAJkWY+2yTEKAzPzhsAvuQyveapFuvynHPOWOgPHyZjrOMPsNmDNLKasJBByFeunXcPb+g4/SSTr6JUs1/EGmN3QLRfhCZQHO90DZWVrHuV/BVF+a3MukheMm8HjkrG/OPsJmfVkyatwTfekNzKoLB4bw= 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=Z90uYUSz; 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="Z90uYUSz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75610C433F1; Tue, 26 Mar 2024 19:56:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1711482984; bh=x4np21dJ2uZ9vYBCKDq3W9rjAOMd4x0jIzHTs6BvC5k=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Z90uYUSzH0W43TFs7w0PYTRMKh3kcbMy5/DQqV/i3rUAt2Lta9+TeWmnD9R5e06bq AZicyFf+T1IdalCf93SV0KeE5wAwVisxNS4ImEA3n4khQ4yxLQf0P8qUoIiaUpazv1 d7Wa7tD0Y5EbgTWL2VCjbmr8L25VCZrXLJ3l4hoA= Date: Tue, 26 Mar 2024 12:56:23 -0700 From: Andrew Morton To: Feng Tang Cc: Borislav Petkov , "V, Narasimhan" , "linux-next@vger.kernel.org" , "linux-mm@kvack.org" , "Aithal, Srikanth" , Dawei Li , Andy Shevchenko , Rasmus Villemoes , Yury Norov , lkml , Vlastimil Babka Subject: Re: Boot failure with kernel BUG at mm/usercopy.c on next-20240325 Message-Id: <20240326125623.266550b81bb36aafc9a2c613@linux-foundation.org> In-Reply-To: References: <20240325125017.GBZgFzCXVxeF50uGVE@fat_crate.local> <20240325113433.e04c2b508ac325630cd113c8@linux-foundation.org> <20240325203714.GJZgHgem2TR1aVAVlU@fat_crate.local> 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 Tue, 26 Mar 2024 10:30:10 +0800 Feng Tang wrote: > Add Vlastimil for slab related topic. > > On Tue, Mar 26, 2024 at 04:37:14AM +0800, Borislav Petkov wrote: > > On Mon, Mar 25, 2024 at 11:34:33AM -0700, Andrew Morton wrote: > > > Thanks, I'll just drop the patch. It didn't receive a very favorable > > > review reception anyway. > > > > See here: > > > > https://lore.kernel.org/all/DM4PR12MB5086B9BDBF32D53DF226CBF489362@DM4PR12MB5086.namprd12.prod.outlook.com/ > > > > folks still need to learn email. :-) > > > > Anyway, apparently there's some fix there. > > The original commit 328c801335d5 ("cpumask: create dedicated kmem > cache for cpumask var") has some benefit, that there are CPU numbers > which are not power of 8, like 144, 288 etc where it will save > some memory. > > And 'slabtop' on a qemu-VM with 16 cpus shows it is surprisingly > non-trivial and has the third largest number of objects: > > 22350 22350 100% 0.13K 745 30 2980K kernfs_node_cache > 11172 10693 0% 0.19K 266 42 2128K dentry > 10240 8222 0% 0.01K 20 512 80K cpumask > > Andrew, if it is worth merging, you can folder my fix into the patch. I'll await a resend, please.