From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0A05C433E6 for ; Tue, 26 Jan 2021 15:06:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 43ACD2310E for ; Tue, 26 Jan 2021 15:06:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 43ACD2310E Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CEF336B006C; Tue, 26 Jan 2021 10:06:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CA04F6B009C; Tue, 26 Jan 2021 10:06:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B8FCD6B009E; Tue, 26 Jan 2021 10:06:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0124.hostedemail.com [216.40.44.124]) by kanga.kvack.org (Postfix) with ESMTP id A38966B006C for ; Tue, 26 Jan 2021 10:06:19 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 683B2181AF5C3 for ; Tue, 26 Jan 2021 15:06:19 +0000 (UTC) X-FDA: 77748252078.29.fire71_2415b1d2758f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id 8BB011801707A for ; Tue, 26 Jan 2021 15:06:14 +0000 (UTC) X-HE-Tag: fire71_2415b1d2758f X-Filterd-Recvd-Size: 4455 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Tue, 26 Jan 2021 15:05:59 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1611673558; h=from:from:reply-to: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=CXc9QyfjbzYkr/9E7kWbWAYLlI4FbRmuEeT8rg+wTwU=; b=RcjpwZyxbSnL27+xPbzI8DyQUePSR4WX2wnQ97UeZMl/oXbeJLspplWQnjrpGmeZ7f77M8 pp/AUp1dBACy/R4ZeJn8VoibDW4Ammk83FYCwymuY2mppYsbTam98rNT5itWkQIDggqXZG gLCeXQM4w8C09vqYIx/Yft3mlmE8rVM= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E4094AF2F; Tue, 26 Jan 2021 15:05:57 +0000 (UTC) Date: Tue, 26 Jan 2021 16:05:55 +0100 From: Michal Hocko To: Matthew Wilcox Cc: Mike Rapoport , Andrew Morton , Alexander Viro , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dan Williams , Dave Hansen , David Hildenbrand , Elena Reshetova , "H. Peter Anvin" , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Mark Rutland , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Rick Edgecombe , Roman Gushchin , Shakeel Butt , Shuah Khan , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org, Hagen Paul Pfeifer , Palmer Dabbelt Subject: Re: [PATCH v16 08/11] secretmem: add memcg accounting Message-ID: <20210126150555.GU827@dhcp22.suse.cz> References: <20210121122723.3446-1-rppt@kernel.org> <20210121122723.3446-9-rppt@kernel.org> <20210125165451.GT827@dhcp22.suse.cz> <20210125213817.GM6332@kernel.org> <20210126144838.GL308988@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210126144838.GL308988@casper.infradead.org> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue 26-01-21 14:48:38, Matthew Wilcox wrote: > On Mon, Jan 25, 2021 at 11:38:17PM +0200, Mike Rapoport wrote: > > I cannot use __GFP_ACCOUNT because cma_alloc() does not use gfp. > > Besides, kmem accounting with __GFP_ACCOUNT does not seem > > to update stats and there was an explicit request for statistics: > > > > https://lore.kernel.org/lkml/CALo0P13aq3GsONnZrksZNU9RtfhMsZXGWhK1n=xYJWQizCd4Zw@mail.gmail.com/ > > > > As for (ab)using NR_SLAB_UNRECLAIMABLE_B, as it was already discussed here: > > > > https://lore.kernel.org/lkml/20201129172625.GD557259@kernel.org/ > > > > I think that a dedicated stats counter would be too much at the moment and > > NR_SLAB_UNRECLAIMABLE_B is the only explicit stat for unreclaimable memory. > > That's not true -- Mlocked is also unreclaimable. And doesn't this > feel more like mlocked memory than unreclaimable slab? It's also > Unevictable, so could be counted there instead. yes, that is indeed true, except the unreclaimable counter is tracking the unevictable LRUs. These pages are not on any LRU and that can cause some confusion. Maybe they shouldn't be so special and they should live on unevistable LRU and get their stats automagically. I definitely do agree that this would be a better fit than NR_SLAB abuse. But considering that this is somehow even more special than mlock then a dedicated counter sounds as even better fit. -- Michal Hocko SUSE Labs