From patchwork Mon Aug 24 15:36:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Schatzberg X-Patchwork-Id: 11733569 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 78C4A14F6 for ; Mon, 24 Aug 2020 15:43:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E2DA2078D for ; Mon, 24 Aug 2020 15:43:37 +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="RItE8EEV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727955AbgHXPnd (ORCPT ); Mon, 24 Aug 2020 11:43:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727924AbgHXPiA (ORCPT ); Mon, 24 Aug 2020 11:38:00 -0400 Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76846C0613ED; Mon, 24 Aug 2020 08:37:59 -0700 (PDT) Received: by mail-qk1-x741.google.com with SMTP id x69so7760291qkb.1; Mon, 24 Aug 2020 08:37:59 -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=Yrl/C8FqKmoOKWHTpqylWzEmmhY9cYd3FuadfFi1qcU=; b=RItE8EEVLrQqxhHs3ZQx7Foq2ps0SM+5TqKNvM/s7lfy4kor2yBW+T08mxhNfvBWdd 2RGDEzkzR8jhYgMV3q7iDQIFJ5N3+DPafuAHlDCJjomPLEEaQCEiUHaXB/fY9433YTsC z4u23zXtSA57ff5mbtLKaqvEvZLJ+9p0xfEpVwFss6stu2xMCbmkqgJvkbrdqwsittxM vxEsBpyiDThrdVRko7aOAFnRIcOS3OruLiTt18HlFoE4bY7VQ4/Se9LhQo94miRVqNqE zltvwW6JVmIcXiauJaAOAdvAv7LmqDFpUiL4nh1upk4yoUY62xPrZP3zlYv/LPKosakr rJZQ== 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=Yrl/C8FqKmoOKWHTpqylWzEmmhY9cYd3FuadfFi1qcU=; b=IpsKEpB+NTXdpJBZsRb5QX9BEijoih79NMp/ZnC9ToImJaucR8Q3G9eWL0m5fPM0K+ ydXwAp+p6aqTFY39IK4aFS6mEFtbuP8nU6bnG1OSVVSO09BoxpI0ijAJvxdQqR81Ei4y uGxMG24FoB7zTCWmucoB/ie0Q1TH0soJGPkTKa5eT26KgOzl3ACqZOdY2jg4Qlebctfn X3Y55729e1R+M5G6YmcpM5RbZFfn1+xfpcJW7MXEmu/bJkOsaRl8f5l7ESxNUyMhPrVV Z84f/El9nE1XpBIuKmx66jKiRtV7VhBl16vH7INGTpoLcGjPLNUqk3OjDMbAisfJ1YRC Tx7g== X-Gm-Message-State: AOAM530Ra13zzwZuaNFhJqPR9kAvqIY5+fuI4NBuRT6Ksye+AGtzvUTr +Of/oBxDiMA65NUmjTaxoyg= X-Google-Smtp-Source: ABdhPJxM2LRyHFxWMV0ffiXTNeWLlg2RxoQyqcPYMgKOZkQDeMNmnS+2daox8wpkc2aWlsKTKcbtIg== X-Received: by 2002:a37:a981:: with SMTP id s123mr4697387qke.324.1598283478654; Mon, 24 Aug 2020 08:37:58 -0700 (PDT) Received: from dschatzberg-fedora-PC0Y6AEN.thefacebook.com ([2620:10d:c091:480::1:dd21]) by smtp.gmail.com with ESMTPSA id m17sm10942758qkn.45.2020.08.24.08.37.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Aug 2020 08:37:57 -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 , Jakub Kicinski , Peter Zijlstra , Ingo Molnar , Mathieu Desnoyers , Michel Lespinasse , Vlastimil Babka , 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, 24 Aug 2020 11:36:01 -0400 Message-Id: <20200824153607.6595-4-schatzberg.dan@gmail.com> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200824153607.6595-1-schatzberg.dan@gmail.com> References: <20200824153607.6595-1-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 | 5 +++-- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b2468c80085d..79c70eef3ec3 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..77c908730be4 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1695,7 +1695,8 @@ 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; int error; @@ -1809,7 +1810,7 @@ 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)) {