From patchwork Thu May 28 13:54:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 11575899 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 48AF6913 for ; Thu, 28 May 2020 13:55:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 29C6620DD4 for ; Thu, 28 May 2020 13:55:37 +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="h4u0/E9S" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390748AbgE1Nzf (ORCPT ); Thu, 28 May 2020 09:55:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36710 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390716AbgE1Nz3 (ORCPT ); Thu, 28 May 2020 09:55:29 -0400 Received: from mail-qk1-x744.google.com (mail-qk1-x744.google.com [IPv6:2607:f8b0:4864:20::744]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7543C05BD1E; Thu, 28 May 2020 06:55:28 -0700 (PDT) Received: by mail-qk1-x744.google.com with SMTP id w3so3105372qkb.6; Thu, 28 May 2020 06:55:28 -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=9ISW/6WZX64f8daVPvqFY1okl3lTrypxE++ROsAseMc=; b=h4u0/E9SlBDy7zE004Yhxe8LFwdOtd/jFTly/4kG0sMKrxsLJsPoCxK54qreUYkgK0 C7cJedYKAPzO3C9CgbPInsWb60fQVA87E8pw9r3OCXO6/RdKCiWz0P/I5ky0SXIoK6Np FgDjlPbtoIcn+pghJNAbepTGyjd439k78xyFR0UCJNyeKLtQ34HEVGUzpBT6SQIcXTxx SB6GW0ZCD8aukfdRP7gHYESpCupUZPqclUUE56uX1JeF01D5TlDgQoSBacTd+mNHWqrs X4aAD6XHrrLpVwXd0q0oefEXI3hWih+JKTC6LIMXUF+d4MC1P5dMj2sKms1rjVY264nS PKAA== 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=9ISW/6WZX64f8daVPvqFY1okl3lTrypxE++ROsAseMc=; b=Sjd8kAS4GHxd4rCA87K9EcWc1yEc7q0EZnf9NJ9mtcIcBohbKQfbVKfL91Qd4EXJEe 46fR0J6w7P1QGnY2E8k2KPE114hagBJ+qBqBpkFctqYOrwTcdTFIgqWTK+5ww14V8B6b Y5kwctdOYzNKJu5zSG4RuNnXKG77isbckSPb1eSLjnr+jRI3Ea3mq7gTNkcd159wPtNg hSqWrQ3wT/dGZ+tSOtaqai3nNKtP8uqp3s9px7Hzjy6KpcLZLs6y5fS3LhgQkNgMrY45 Li0+nYoLL1dOQCHuE4IXLvDSYU288fGe5KLY61zZe5vdUBxpBiA9sR/Dykm6BC0JIGRu uvUw== X-Gm-Message-State: AOAM533mRdl4M74daWPAg4iS+3AqLOtsmoNNaeBPk7LOfBp7XRsOfe88 5WtSXfURc5KkrIAIqDbNbJ8= X-Google-Smtp-Source: ABdhPJzrlVywN4JlmAU2ZM/nC5B3Ll644kitWP/9qECB6fQhLzh4HwCgQpi3FHH9/Li3NZeoEl/LKA== X-Received: by 2002:ae9:e901:: with SMTP id x1mr2717709qkf.131.1590674127957; Thu, 28 May 2020 06:55:27 -0700 (PDT) Received: from dschatzberg-fedora-PC0Y6AEN.thefacebook.com ([2620:10d:c091:480::1:1cb7]) by smtp.gmail.com with ESMTPSA id l186sm4890889qkf.89.2020.05.28.06.55.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 May 2020 06:55:26 -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 , Thomas Gleixner , Ingo Molnar , "Peter Zijlstra (Intel)" , Mathieu Desnoyers , Andrea Arcangeli , 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: Thu, 28 May 2020 09:54:38 -0400 Message-Id: <20200528135444.11508-4-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200528135444.11508-1-schatzberg.dan@gmail.com> References: <20200528135444.11508-1-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 a3b97f103966..383d88c1c105 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6438,7 +6438,8 @@ 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. @@ -6482,8 +6483,12 @@ 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 bd8840082c94..d2efa1a44311 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)) {