From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06441C433ED for ; Tue, 4 May 2021 20:02:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6AAC613CB for ; Tue, 4 May 2021 20:02:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232675AbhEDUDR (ORCPT ); Tue, 4 May 2021 16:03:17 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:50409 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232582AbhEDUDQ (ORCPT ); Tue, 4 May 2021 16:03:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620158538; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VE7sisr51bWaASPhEsNZ/WxzuZMuCTfCXf9ed9Dm2Lw=; b=P9bdSKVD92RGMQWbFhkGmorsbIQWIw6CXJ6oF4UirhGOry3Bhv5whxq6bTXVwesnDu9i2Z PACBbnB7ZW/ZdfF9Z3P3apCuhZbjZ004W6G4JUvXi9+9aVD39PiVH8Axqb1ABLXppNg9pR M4wXUyYZcZcVsQ3K8VvAdTjaxyuSFu4= Received: from mail-qk1-f200.google.com (mail-qk1-f200.google.com [209.85.222.200]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-295-_kuK15OsOISvx9jGq1Cwrw-1; Tue, 04 May 2021 16:02:16 -0400 X-MC-Unique: _kuK15OsOISvx9jGq1Cwrw-1 Received: by mail-qk1-f200.google.com with SMTP id p133-20020a37428b0000b02902de31dd8da3so8365267qka.1 for ; Tue, 04 May 2021 13:02:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:subject:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=VE7sisr51bWaASPhEsNZ/WxzuZMuCTfCXf9ed9Dm2Lw=; b=lQl4VQURHzwrNL4h1/8OEKwIGUtn81i9V9c+kADfhXEeky/UwLRwvBBNh7sevzg6iM 83N5JZtn2a2uW3J/p3nKI3MGdQFrCHSGrzNXwVFPyPwMH+F3IR9Veu/IFPNn1y5CQDUq jNhkieteEw29EFFx8TaSSSn9KQFv/3cNH+wL0QxlPVI/LNTGO3qgog25sxIm+mp+Brjn fgTHwsdA1iZw4KN2PAYCxz/BNiiJlXL7n1M3nGNb7UwWMin3h7YyYOBvn3haUbvEpOJC jmtl6SmTObvtgy6ugGqFFAPRenBjL0ESR5HGuhLgh42mVaH6kx8ZjDjT9rUcK+ZyV/LS B+6g== X-Gm-Message-State: AOAM530l7eIZYiQ0wbVUnRcAHPAE+QGFgoqA6r4ayvh+On8EjoSNxk2c q9YsWOV83UhLEEoEfetcUfx96a56XjDh2nV+9xc3aL1KNgLtGdVFfOlTYr6SaHfPKZ1UjpQd6Z6 yUDhjiH1+l3PjKa0HjvYewnyv X-Received: by 2002:a37:8906:: with SMTP id l6mr27594724qkd.198.1620158536437; Tue, 04 May 2021 13:02:16 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzew9UQi58ZCeX2QWSS7d98RivIluTCwTthqw1aP/iQD40qJkD8jFbyDdr63EWdkEgiv7Xbpg== X-Received: by 2002:a37:8906:: with SMTP id l6mr27594691qkd.198.1620158536155; Tue, 04 May 2021 13:02:16 -0700 (PDT) Received: from llong.remote.csb ([2601:191:8500:76c0::cdbc]) by smtp.gmail.com with ESMTPSA id t6sm2442450qkh.29.2021.05.04.13.02.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 04 May 2021 13:02:15 -0700 (PDT) From: Waiman Long X-Google-Original-From: Waiman Long Subject: Re: [PATCH v2 1/2] mm: memcg/slab: Properly set up gfp flags for objcg pointer array To: Shakeel Butt Cc: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin , LKML , Cgroups , Linux MM References: <20210504132350.4693-1-longman@redhat.com> <20210504132350.4693-2-longman@redhat.com> Message-ID: <267501a0-f416-4058-70d3-e32eeec3d6da@redhat.com> Date: Tue, 4 May 2021 16:02:14 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/4/21 3:37 PM, Shakeel Butt wrote: > On Tue, May 4, 2021 at 6:24 AM Waiman Long wrote: >> Since the merging of the new slab memory controller in v5.9, the page >> structure may store a pointer to obj_cgroup pointer array for slab pages. >> Currently, only the __GFP_ACCOUNT bit is masked off. However, the array >> is not readily reclaimable and doesn't need to come from the DMA buffer. >> So those GFP bits should be masked off as well. >> >> Do the flag bit clearing at memcg_alloc_page_obj_cgroups() to make sure >> that it is consistently applied no matter where it is called. >> >> Fixes: 286e04b8ed7a ("mm: memcg/slab: allocate obj_cgroups for non-root slab pages") >> Signed-off-by: Waiman Long >> --- >> mm/memcontrol.c | 8 ++++++++ >> mm/slab.h | 1 - >> 2 files changed, 8 insertions(+), 1 deletion(-) >> >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index c100265dc393..5e3b4f23b830 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c >> @@ -2863,6 +2863,13 @@ static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg) >> } >> >> #ifdef CONFIG_MEMCG_KMEM >> +/* >> + * The allocated objcg pointers array is not accounted directly. >> + * Moreover, it should not come from DMA buffer and is not readily >> + * reclaimable. So those GFP bits should be masked off. >> + */ >> +#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) > What about __GFP_DMA32? Does it matter? It seems like DMA32 requests > go to normal caches. I included __GFP_DMA32 in my first draft patch. However, __GFP_DMA32 is not considered in determining the right kmalloc_type() (patch 2), so I took it out to make it consistent. I can certainly add it back. Cheers, Longman