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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8B75C433FE for ; Wed, 13 Oct 2021 16:41:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7A00C611ED for ; Wed, 13 Oct 2021 16:41:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7A00C611ED Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id CDAEE900003; Wed, 13 Oct 2021 12:41:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C894F900002; Wed, 13 Oct 2021 12:41:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B4FFE900003; Wed, 13 Oct 2021 12:41:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0098.hostedemail.com [216.40.44.98]) by kanga.kvack.org (Postfix) with ESMTP id A2AEC900002 for ; Wed, 13 Oct 2021 12:41:31 -0400 (EDT) Received: from smtpin35.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 4E6072C6AA for ; Wed, 13 Oct 2021 16:41:31 +0000 (UTC) X-FDA: 78691979982.35.FE18A7D Received: from mail-lf1-f46.google.com (mail-lf1-f46.google.com [209.85.167.46]) by imf06.hostedemail.com (Postfix) with ESMTP id 997B5801A89C for ; Wed, 13 Oct 2021 16:41:30 +0000 (UTC) Received: by mail-lf1-f46.google.com with SMTP id r19so14179059lfe.10 for ; Wed, 13 Oct 2021 09:41:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=NPgT6NXkn4m3r7Gqf6Xmq+r6xoZWYcfKJwECpES7gkc=; b=j68WJ+Mb8FMm8l4fHho6NGTbOMBz8V0Esm2L6IrXhNA4GrhqPjtC5bpmOiBZd6f/SJ hVygO36l2sFF8R34+9Q8XkwmIi0piebgNava8RuVeQwHa6bCvsGFsLpTEmNn7aHZX3wI eyD+/2xd6PmgZZLbIh2rCbvv2q/TsOiRUsaa25+sW5t+RjDNFiFduRI4g4CO/4XbeHrm PB31+y8sTL3/fi58B0snsJWsdDDf4qlvvs5PshkrUWq2pk64SvvtcNLGNa6x+QHh83od GFap54IAUwgcHkV6ZdM6uPMGnIiXsZa67MZH0t1OysgFihi8CYe/q7+/lvQ58teM0na0 cgpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=NPgT6NXkn4m3r7Gqf6Xmq+r6xoZWYcfKJwECpES7gkc=; b=OX5aG3UOSzbqPt5zBfCiuPa7POvjfWq3VHOUkZaweBKps77Om083j4jTKwHqh10xpQ hRP9j34Z0uykK/wCc+Susb+8eYIFgANCQE0aLRl/EQmJSx9ic5mD5Z005i66zKuCmhsr 4MHYM5W7+uVXUIZ/PCppp/4+pgGUjhStGvTvbrtMrR5EBfJZ0Nsx0NQRTawpu78DjH+0 NDnIf5iTNoDv17MD4o5cPBRJP/Wodrr2kENTKpLjIFSf/V2QwcyugbFIVuraQBGtzri3 TRDLiBZP6l3Z/MJMgOogSL3Df+fA27uQTl2cF7iIQZMLcv+saPJgXZTddJkMSzrSaSSH Ia/g== X-Gm-Message-State: AOAM5324CUOSNFA3Ucx8Wm/XIanackkHAW/LUrrakfk8wKhH0jMocx9c duyPBcd4/psCN487+u6fEMZ17D4vXQxZ2VV182OAaA== X-Google-Smtp-Source: ABdhPJxQ7dROOW3GwYwJZv5cEP72W9nSPXf3G+FjF80FpcnyLSbosTXFRKMtNJ72yGKJsFPgIFJuaApet6UQxb5ou5s= X-Received: by 2002:ac2:4e02:: with SMTP id e2mr113350lfr.264.1634143286611; Wed, 13 Oct 2021 09:41:26 -0700 (PDT) MIME-Version: 1.0 References: <0baa2b26-a41b-acab-b75d-72ec241f5151@virtuozzo.com> <60df0efd-f458-a13c-7c89-749bdab21d1d@virtuozzo.com> In-Reply-To: From: Shakeel Butt Date: Wed, 13 Oct 2021 09:41:15 -0700 Message-ID: Subject: Re: [PATCH mm v3] memcg: enable memory accounting in __alloc_pages_bulk To: Michal Hocko Cc: Vasily Averin , Johannes Weiner , Vladimir Davydov , Andrew Morton , Mel Gorman , Roman Gushchin , Uladzislau Rezki , Vlastimil Babka , Cgroups , Linux MM , LKML , kernel@openvz.org Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=j68WJ+Mb; spf=pass (imf06.hostedemail.com: domain of shakeelb@google.com designates 209.85.167.46 as permitted sender) smtp.mailfrom=shakeelb@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 997B5801A89C X-Stat-Signature: yj77hr7fooz4egwnom4xnwxatmmf138d X-HE-Tag: 1634143290-144400 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, Oct 12, 2021 at 11:24 AM Michal Hocko wrote: > > On Tue 12-10-21 09:08:38, Shakeel Butt wrote: > > On Tue, Oct 12, 2021 at 8:36 AM Michal Hocko wrote: > > > > > > On Tue 12-10-21 17:58:21, Vasily Averin wrote: > > > > Enable memory accounting for bulk page allocator. > > > > > > ENOCHANGELOG > > > > > > And I have to say I am not very happy about the solution. It adds a very > > > tricky code where it splits different charging steps apart. > > > > > > Would it be just too inefficient to charge page-by-page once all pages > > > are already taken away from the pcp lists? This bulk should be small so > > > this shouldn't really cause massive problems. I mean something like > > > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > > index b37435c274cf..8bcd69195ef5 100644 > > > --- a/mm/page_alloc.c > > > +++ b/mm/page_alloc.c > > > @@ -5308,6 +5308,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, > > > > > > local_unlock_irqrestore(&pagesets.lock, flags); > > > > > > + if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT)) { > > > + /* charge pages here */ > > > + } > > > > It is not that simple because __alloc_pages_bulk only allocate pages > > for empty slots in the page_array provided by the caller. > > > > The failure handling for post charging would be more complicated. > > If this is really that complicated (I haven't tried) then it would be > much more simple to completely skip the bulk allocator for __GFP_ACCOUNT > rather than add a tricky code. The bulk allocator is meant to be used > for ultra hot paths and memcg charging along with the reclaim doesn't > really fit into that model anyway. Or are there any actual users who > really need bulk allocator optimization and also need memcg accounting? Bulk allocator is being used for vmalloc and we have several kvmalloc() with __GFP_ACCOUNT allocations. It seems like Vasily has some ideas, so let's wait for his next version.