From patchwork Mon Feb 24 22:17:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 11401855 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 5C14B14E3 for ; Mon, 24 Feb 2020 22:18:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B39E24650 for ; Mon, 24 Feb 2020 22:18:14 +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="LPtAbAQL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728252AbgBXWSN (ORCPT ); Mon, 24 Feb 2020 17:18:13 -0500 Received: from mail-qk1-f195.google.com ([209.85.222.195]:36088 "EHLO mail-qk1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728087AbgBXWSM (ORCPT ); Mon, 24 Feb 2020 17:18:12 -0500 Received: by mail-qk1-f195.google.com with SMTP id f3so7244250qkh.3; Mon, 24 Feb 2020 14:18:11 -0800 (PST) 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=SCkGRqTJz70QV81Hpnays5VS0skwnz1lHvPTyvLahTQ=; b=LPtAbAQL+o6zGkxQYVl6oUm314BGitf+8dwHRfBTwvX2vCIWMWsdxtAx6cO5EURiDw hT86AELE/sWFsqn9UE2P89uSDbn1Pcd+L92hHaxnAInur0nmUwg1wBcQ495+4XM5EjC1 tO9EoQDeJhaVKrF0wydjSdqi6PRYB+QUTgmBr899l6OOHs9b1EiWl6VS8He+h2WW/9G7 tWhj3S5Fw0ZbWtgq6sa+QVDF1vnINI+i2RL1yrpk2XdzXISlUSDia42BCLI6PAhbCocY 5S9Qq1UTq0TgT5HKK7tcjG32nutDmkHKGgw24VRqDVYre0dFT/dxZMP95KgmYJQxLARY 5CWw== 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=SCkGRqTJz70QV81Hpnays5VS0skwnz1lHvPTyvLahTQ=; b=RfvgqaFvtaXsK80Z+Om2oUpYC6NwNY3dFPge0YEkTW8TaQ+t2530jtpHzyLetjHvPB 2+IsNtW+6Ybc5c2Fnn4FMybqUsp12lD8bmSg07RGwGX8AC4XbWYF9Rs4RGTh4m/acuYm Jk6hwxcsYzKzZJZtBe9LLRJwMPc388rjpv7kKZkHzcGzno97rSGzp48HWyVPVL524M+G xzXyj+vdMNx7vap4MtMz/6rOszPqB6z5KWg8KwlMn9xnmJ6PhoVjFfNEVQIJY2JQ1ROK p7LXgxIoXZAHeMBStxQwzL5P5ifDgnUKxgxqp11esZISGrXOGAOxrFEw4wpwwk09PzVk /50w== X-Gm-Message-State: APjAAAVqL8bALWaNpmeqKLcWetTsM6BhAkeVKXKk3tMzIbw7enGB6MRA GxB+VtdJn3hej5KJZetSGd0= X-Google-Smtp-Source: APXvYqxWDwQIhlfPU7vYI8DHfzyLzFKyJd3oBZ1Xvj/9j0Xcen+L3F9yigwUtJlebcEkS8YmknFljQ== X-Received: by 2002:a37:e0d:: with SMTP id 13mr36331326qko.145.1582582691321; Mon, 24 Feb 2020 14:18:11 -0800 (PST) Received: from dschatzberg-fedora-PC0Y6AEN.thefacebook.com ([2620:10d:c091:500::2:b19b]) by smtp.gmail.com with ESMTPSA id o17sm6648870qtj.80.2020.02.24.14.18.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Feb 2020 14:18:10 -0800 (PST) From: Dan Schatzberg Cc: Dan Schatzberg , Jens Axboe , Tejun Heo , Li Zefan , Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Hugh Dickins , Roman Gushchin , Shakeel Butt , Chris Down , Yang Shi , Thomas Gleixner , 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 v3 2/3] mm: Charge active memcg when no mm is set Date: Mon, 24 Feb 2020 17:17:46 -0500 Message-Id: <4456276af198412b2d41cd09d246cd20e0c6d22a.1582581887.git.schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.21.1 In-Reply-To: References: 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 Signed-off-by: Dan Schatzberg Acked-by: Hugh Dickins --- 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 d09776cd6e10..222e4aac0c85 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6319,7 +6319,8 @@ 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. @@ -6363,8 +6364,12 @@ 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 c8f7540ef048..8664c97851f2 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1631,7 +1631,7 @@ 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; @@ -1766,7 +1766,7 @@ 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)) {