From patchwork Mon Apr 20 22:39:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 11500043 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EA8201392 for ; Mon, 20 Apr 2020 22:41:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA53A206F9 for ; Mon, 20 Apr 2020 22:41:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LBEn7bne" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727895AbgDTWlr (ORCPT ); Mon, 20 Apr 2020 18:41:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725958AbgDTWlr (ORCPT ); Mon, 20 Apr 2020 18:41:47 -0400 Received: from mail-qk1-x743.google.com (mail-qk1-x743.google.com [IPv6:2607:f8b0:4864:20::743]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7E8DC061A0C; Mon, 20 Apr 2020 15:41:46 -0700 (PDT) Received: by mail-qk1-x743.google.com with SMTP id 20so12594141qkl.10; Mon, 20 Apr 2020 15:41:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=1xs7a52HdDCbAExnqSe5+2K/TyJ01Rp0raQ7acG2FHw=; b=LBEn7bneTlbqWBhqE2IIOuFPDU45rQRp1EY5buf++UFJUWy3jsS+81KMlghgb3LFBk hFj25ZFBr8VBuLNn4PaIzXR1hBoyXf8+sEdvG48kqGl3lQQ2wjQlb/XInPNC+BtMbt2S WN3T3aPyHlIH8WHoKeIizh0txrP2MwcLxuNRjsv2l2Bm9nQJjVamOygS4H4jd96tmWun kUiUxVrStl8llq4Quf4MN3w6oZmW/F7Dv9Gd1sAAUUprqFBlUmSHZ8DXteIGwybfWzG6 TkMIZe/0wZgW4z3G5XJrnFbnOcP1/15w+yMkGWWmcmIjiaZEw0qijSD2sWEVZQg74bMm ezSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=1xs7a52HdDCbAExnqSe5+2K/TyJ01Rp0raQ7acG2FHw=; b=nJVDlmnyW8PFxeVoo+9ALr6dNqDigGBiiX0yOWY03AL0+jLKoG+Q7Kq9wcgA1TgJVr 3RPhDxvzl6gE/zmSVANCtvV9zBTVtIX64WM8tUhRjpTWW0GyYD4RyrHQ0Rf9iSJlvUsG l10xp6ueShuiCPiW1rnKaQiWhBDl4qY0EoWNE/vnPqzW8l+O/Jc3jwMwaVR26jDweHtW gewvvoNXbZIgN9qFgVPqM7+eMMY9cVRu7ChWmuFBK0JLdOUyguE/9p9CovJKMdzzAgep fYUODP2zfba3rREgz/A9GJIvIN8Dz/kpvA8MlsVDkku8QDhTKd+mAvFlnbSJVk4WCSWI bT5Q== X-Gm-Message-State: AGi0PuZ8fkG0C6JpA0pcL5lFq6Dd/SyTooN0GpsVGPRyE3walB2y4HFd +8AMjnTmss8m8PbqIzMAMZ8= X-Google-Smtp-Source: APiQypL4UcYluQEWwxN6yDbDlj/pGdI0PL/O26k1R1mC5DVwhSgdhKf4O8pmqQGMjlFBHeB5aBBAFA== X-Received: by 2002:a05:620a:2054:: with SMTP id d20mr17844738qka.496.1587422505955; Mon, 20 Apr 2020 15:41:45 -0700 (PDT) Received: from dschatzberg-fedora-PC0Y6AEN.thefacebook.com ([2620:10d:c091:480::1:b0d9]) by smtp.gmail.com with ESMTPSA id j90sm511052qte.20.2020.04.20.15.41.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Apr 2020 15:41:45 -0700 (PDT) From: Dan Schatzberg Cc: Dan Schatzberg , Johannes Weiner , Tejun Heo , Chris Down , Shakeel Butt , Jens Axboe , Alexander Viro , Jan Kara , Amir Goldstein , Li Zefan , Michal Hocko , Vladimir Davydov , Andrew Morton , Hugh Dickins , Roman Gushchin , Yang Shi , "Peter Zijlstra (Intel)" , Ingo Molnar , Mathieu Desnoyers , Andrea Arcangeli , Thomas Gleixner , linux-block@vger.kernel.org (open list:BLOCK LAYER), linux-kernel@vger.kernel.org (open list), linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)), cgroups@vger.kernel.org (open list:CONTROL GROUP (CGROUP)), linux-mm@kvack.org (open list:CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)) Subject: [PATCH 3/4] mm: Charge active memcg when no mm is set Date: Mon, 20 Apr 2020 18:39:31 -0400 Message-Id: <20200420223936.6773-4-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420223936.6773-1-schatzberg.dan@gmail.com> References: <20200420223936.6773-1-schatzberg.dan@gmail.com> MIME-Version: 1.0 To: unlisted-recipients:; (no To-header on input) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org memalloc_use_memcg() worked for kernel allocations but was silently ignored for user pages. 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. Previously, if a NULL mm was passed to mem_cgroup_try_charge (case 3) it 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/memcontrol.c | 11 ++++++++--- mm/shmem.c | 4 ++-- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5beea03dd58a..af68d1d7b456 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6435,7 +6435,8 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root, * @compound: charge the page as compound or small page * * 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, with *@memcgp pointing to the charged memcg. * Otherwise, an error code is returned. @@ -6479,8 +6480,12 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm, } } - if (!memcg) - memcg = get_mem_cgroup_from_mm(mm); + if (!memcg) { + if (!mm) + memcg = get_mem_cgroup_from_current(); + else + memcg = get_mem_cgroup_from_mm(mm); + } ret = try_charge(memcg, gfp_mask, nr_pages); diff --git a/mm/shmem.c b/mm/shmem.c index d722eb830317..8c8ffc35a957 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1618,7 +1618,7 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, { struct address_space *mapping = inode->i_mapping; struct shmem_inode_info *info = SHMEM_I(inode); - struct mm_struct *charge_mm = vma ? vma->vm_mm : current->mm; + struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL; struct mem_cgroup *memcg; struct page *page; swp_entry_t swap; @@ -1753,7 +1753,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, } sbinfo = SHMEM_SB(inode->i_sb); - charge_mm = vma ? vma->vm_mm : current->mm; + charge_mm = vma ? vma->vm_mm : NULL; page = find_lock_entry(mapping, index); if (xa_is_value(page)) {