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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 29222C433E6 for ; Tue, 16 Mar 2021 15:51:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E57AE65104 for ; Tue, 16 Mar 2021 15:51:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237355AbhCPPut (ORCPT ); Tue, 16 Mar 2021 11:50:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237538AbhCPPub (ORCPT ); Tue, 16 Mar 2021 11:50:31 -0400 Received: from mail-lf1-x136.google.com (mail-lf1-x136.google.com [IPv6:2a00:1450:4864:20::136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22159C06174A for ; Tue, 16 Mar 2021 08:50:30 -0700 (PDT) Received: by mail-lf1-x136.google.com with SMTP id v2so50162889lft.9 for ; Tue, 16 Mar 2021 08:50:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WwakdtxuHaTN5z0HCiQ4MNVrrN9llL1dGHrwS+1rEFI=; b=Y8vlN3SI/ykxQTjQbv4kH+9CK9WxCxroUfhO5YAG/Q06fEfhC7gmihPG0b2gkbg7p2 BJcipNhPpwfAYZQawmSVw4SuDq9HgHqrnJ72QN6YzAPc/iS45ymhVnlsheWAmhIcRFFC 5n043KRfcygMCCaESFPz/xle+ga7BJvXFjAgDJ2KE3+DwTFKrqQGRARQHbIWQizdgYAx yjC00EWkXA7CGN93CjqVoC9HMMj3XE/OgUEkwHEjGGzbImbrc7x5KngmL6YhRLcDwLnF rOlY48nIfjjcwEFdjlIDwqnZrPTEBtobD5wnEMK+86kKf6TRdXu36PZTzykBdCGIV382 K6bQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WwakdtxuHaTN5z0HCiQ4MNVrrN9llL1dGHrwS+1rEFI=; b=baUebZ5hnaVQCGRYEAr8m8D2XyHhlxhaFz64mel0gvt7ysdHPJRMYdzyMpWrUC2Gz6 hVl8xKRlwNheFeo9o6QtQbIOjjtY7wwJMj94KeITpcFpUhQcucyi3+Nq8R7KMACP7Qum rpVjcdOSNVpSfGnIHVwxR3tDA0JQ4FJGsA2UmowwX/R9qaa1GSlOx4zCat8DyMEi4Q41 JElJkc3fQ9dAoVb3kJcklqsZ5y/XDAzVFuNX3Dr1uJo6RGK7PSvy5oJJLT1LceEiVsyn /QYrsF27P+MW51zkSMlAs/kGtfu3LyBdx7sU69bbEj32nB2OFfbBJWZ0tEtRm8G2t8mL xycw== X-Gm-Message-State: AOAM5320Mx/I8vS8OJ4sdOgIxhk1PC22/PuyWxb+37xwMD319CoKEbqC zeaNQWPKNTfmJJvYzcZkBqy1hbHop6qXu/IvIxkZiw== X-Google-Smtp-Source: ABdhPJyZ/vV2IRRHujPOKeVa0QetQ4VOSuoAxfKAEM82kauFP2bOtUCTQcIxCf4r+D48huq9DC6J/O4En2deKcexRrA= X-Received: by 2002:a05:6512:39c9:: with SMTP id k9mr11272677lfu.432.1615909828360; Tue, 16 Mar 2021 08:50:28 -0700 (PDT) MIME-Version: 1.0 References: <20210316153655.500806-1-schatzberg.dan@gmail.com> <20210316153655.500806-3-schatzberg.dan@gmail.com> In-Reply-To: <20210316153655.500806-3-schatzberg.dan@gmail.com> From: Shakeel Butt Date: Tue, 16 Mar 2021 08:50:16 -0700 Message-ID: Subject: Re: [PATCH 2/3] mm: Charge active memcg when no mm is set To: Dan Schatzberg Cc: Jens Axboe , Tejun Heo , Zefan Li , Johannes Weiner , Andrew Morton , Michal Hocko , Vladimir Davydov , Hugh Dickins , Roman Gushchin , Muchun Song , Alex Shi , Alexander Duyck , Chris Down , Yafang Shao , Wei Yang , "open list:BLOCK LAYER" , open list , "open list:CONTROL GROUP (CGROUP)" , "open list:MEMORY MANAGEMENT" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 16, 2021 at 8:37 AM Dan Schatzberg wrote: > > memalloc_use_memcg() worked for kernel allocations but was silently > ignored for user pages. set_active_memcg() > > This patch establishes a precedence order for who gets charged: > > 1. If there is a memcg associated with the page already, that memcg is > charged. This happens during swapin. > > 2. If an explicit mm is passed, mm->memcg is charged. This happens > during page faults, which can be triggered in remote VMs (eg gup). > > 3. Otherwise consult the current process context. If it has configured > a current->active_memcg, use that. Otherwise, current->mm->memcg. It's a bit more sophisticated than current->active_memcg. It has been extended to work in interrupt context as well. > > Previously, if a NULL mm was passed to mem_cgroup_try_charge (case 3) it mem_cgroup_charge() > would always charge the root cgroup. Now it looks up the current > active_memcg first (falling back to charging the root cgroup if not > set). > > Signed-off-by: Dan Schatzberg > Acked-by: Johannes Weiner > Acked-by: Tejun Heo > Acked-by: Chris Down > Reviewed-by: Shakeel Butt > --- > mm/filemap.c | 2 +- > mm/memcontrol.c | 14 +++++++++++--- > mm/shmem.c | 4 ++-- > 3 files changed, 14 insertions(+), 6 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 43700480d897..5135f330f05c 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -843,7 +843,7 @@ noinline int __add_to_page_cache_locked(struct page *page, > page->index = offset; > > if (!huge) { > - error = mem_cgroup_charge(page, current->mm, gfp); > + error = mem_cgroup_charge(page, NULL, gfp); > if (error) > goto error; > charged = true; > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index e064ac0d850a..9a1b23ed3412 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -6690,7 +6690,8 @@ void mem_cgroup_calculate_protection(struct mem_cgroup *root, > * @gfp_mask: reclaim mode > * > * Try to charge @page to the memcg that @mm belongs to, reclaiming > - * pages according to @gfp_mask if necessary. > + * pages according to @gfp_mask if necessary. if @mm is NULL, try to > + * charge to the active memcg. > * > * Returns 0 on success. Otherwise, an error code is returned. > */ > @@ -6726,8 +6727,15 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) > rcu_read_unlock(); > } > > - if (!memcg) > - memcg = get_mem_cgroup_from_mm(mm); > + if (!memcg) { > + if (!mm) { > + memcg = get_mem_cgroup_from_current(); > + if (!memcg) > + memcg = get_mem_cgroup_from_mm(current->mm); > + } else { > + memcg = get_mem_cgroup_from_mm(mm); > + } > + } You will need to rebase to the latest mm tree. This code has changed.