From patchwork Mon Aug 31 15:36:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 11746537 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 A36BB109B for ; Mon, 31 Aug 2020 15:37:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 81B8420866 for ; Mon, 31 Aug 2020 15:37:38 +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="SjePWpDm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729233AbgHaPhh (ORCPT ); Mon, 31 Aug 2020 11:37:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728908AbgHaPhb (ORCPT ); Mon, 31 Aug 2020 11:37:31 -0400 Received: from mail-qv1-xf42.google.com (mail-qv1-xf42.google.com [IPv6:2607:f8b0:4864:20::f42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1573C061573; Mon, 31 Aug 2020 08:37:30 -0700 (PDT) Received: by mail-qv1-xf42.google.com with SMTP id b13so2696945qvl.2; Mon, 31 Aug 2020 08:37:30 -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=hFNO1srh3AW4C+hy+7CfuD56Hs7de0B4v+mt5P6Q+8c=; b=SjePWpDm/dcOfaWyG090sIQ82qRogNC8U9o/SXOsilJibfKn37U7NrP6cYs9z13ajn 3ahnbXMI1dfgdzV1jsX4P8YPuyM1wY2QGXQiesxpHGGEg3Z23HYwzkk62guOns9HMJyO mv5bVZQTbHPtdEJ+eNlOenVGaVNmy48r50T0qx1KJrkByftLK+OzvzENGehdjQZ0EdVJ SbKPXAl9lN5Bz1sTMxYIYgFWi6dPAG2dwLhw1nXA9usckN3AXJXudsT9uUJdRuIs/Ntq 5nv1yGY0UIXNQDK7x6fl3OY/BjqkvDLJzoM8kbzBSnvSW8Q8tEl7Yp4cPcUq9xxnCReP 1UgQ== 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=hFNO1srh3AW4C+hy+7CfuD56Hs7de0B4v+mt5P6Q+8c=; b=lci5gG1UJ8ZSjJmCZcWM7oDaTTsxTfycHF6vfNutBUvyVNaW0eoMO6EdQQfGBk/6RQ twPIBCxfswZIIfqE97nftkvudGeWcLD+0Uz11M8zx/0An+2QOY4MeOiMwqlDA5kSNWX7 Hgm8Hp4ISgdrHdcLhZANIouiXjEA4o22NOo/dCnJ/6u4hR3qJtkAYmQg0fAQB/lY6Knr 2DoNUXCrDEAX2Do0Kd7GmpfCR5QTeGbqt2Ar6tQ+iisJCgI8q8piJAXu4ng6FOEEkMHO lQpbudNpY1BPbe9bp7DPOi0INxUb9hJ5tpjFfycSO2zPWJmTYXG/snqXtk1ObJzKrheD 4dqQ== X-Gm-Message-State: AOAM532zn0KPP4GQKNxH4qwz9bhJPgvQyJkTRUhth/cjdZnrVyZyNXup MAltodrlT5ORrw17BTMW0qo= X-Google-Smtp-Source: ABdhPJxZrAVMLKA6PaN3RQHI9DyNFWZHOVofg01sLYGajv8EisNnh3wB37+tmq28zRDNQhabk9LCkg== X-Received: by 2002:ad4:430d:: with SMTP id c13mr1642259qvs.49.1598888249829; Mon, 31 Aug 2020 08:37:29 -0700 (PDT) Received: from dschatzberg-fedora-PC0Y6AEN.thefacebook.com ([2620:10d:c091:480::1:2edc]) by smtp.gmail.com with ESMTPSA id s5sm9908872qke.120.2020.08.31.08.37.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Aug 2020 08:37:29 -0700 (PDT) From: Dan Schatzberg Cc: Dan Schatzberg , Johannes Weiner , Tejun Heo , Chris Down , Shakeel Butt , Jens Axboe , Li Zefan , Michal Hocko , Vladimir Davydov , Andrew Morton , Hugh Dickins , Roman Gushchin , Yang Shi , Jakub Kicinski , linux-block@vger.kernel.org (open list:BLOCK LAYER), linux-kernel@vger.kernel.org (open list), cgroups@vger.kernel.org (open list:CONTROL GROUP (CGROUP)), linux-mm@kvack.org (open list:CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)) Subject: [PATCH 2/3] mm: Charge active memcg when no mm is set Date: Mon, 31 Aug 2020 11:36:59 -0400 Message-Id: <20200831153704.16848-3-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200831153704.16848-1-schatzberg.dan@gmail.com> References: <20200831153704.16848-1-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 e27ac6d79a32..877778b792da 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6676,7 +6676,8 @@ 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. */ @@ -6712,8 +6713,12 @@ 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(); + else + memcg = get_mem_cgroup_from_mm(mm); + } ret = try_charge(memcg, gfp_mask, nr_pages); if (ret) diff --git a/mm/shmem.c b/mm/shmem.c index 271548ca20f3..1139f52ac4ee 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1695,7 +1695,7 @@ 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 page *page; swp_entry_t swap; int error; @@ -1809,7 +1809,7 @@ 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)) {