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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 DC81BC433DF for ; Mon, 15 Jun 2020 09:13:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BBD2120707 for ; Mon, 15 Jun 2020 09:13:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592212421; bh=h/zGVRRAzSvBehgKKBcN1OLvI8BuwmBaO01iJ0fEU0Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=HSDgYhWXfOb56W4tsyUzfMqi8TV6JqJ5pKTmf8DXOAYh44hfInXB64fknMK5g6nkm SfiCEC/PQzOu5oXnaZ0HiaClgqCiuD7JOeO9B8ApFHjiOBsjnS9Jewy4wKDL1NnH9L MeKnVONYguVTLIYJCS1lBLBrntJvV2jt6mWUhWd8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729298AbgFOJNk (ORCPT ); Mon, 15 Jun 2020 05:13:40 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:38448 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729073AbgFOJNj (ORCPT ); Mon, 15 Jun 2020 05:13:39 -0400 Received: by mail-wr1-f66.google.com with SMTP id e1so16300158wrt.5 for ; Mon, 15 Jun 2020 02:13:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ovYDqOmj0RcWezm825Y7rApyl3DGymdbL53dv7LzD2A=; b=HO8p5Ja8sDqRpPLcpbGlRAMk5bZEDqOb+1GiwbhHCEFjwUPcYrTKZK50BSzSwS6rLC btZFbNMIlTPoZLtnq1ymYWU5y6jOgTfVo4uGD9G4IsKgEEbXLpvoX7iOBk9eWkeGI55G 20Z4t9gTCle76P7rMqFyDnB7tJ00fPli4L7M6lNWs0YTdYSM9rUtYst80yjcctU7MEfH b+Gz5peCmHXGVrkTNh+MgcAEpKprmJrpSKh8Mdiq5NVUvkbBwdLxzO3qZAbJiXvWdNQX ZuNRsiRbOPm/dctMWezBRSWQ2jDnsV287EGDRvkGKLGI9UN4tiJ9QN7p7TBydmwExwie BMsg== X-Gm-Message-State: AOAM533544pPDiNXhWVYJ8J/XioB4Ode32+SQBd3JJ3g4tC+STf8GcZS eh/oXcEzKGZRAnd6uKvIPeO/VTCf X-Google-Smtp-Source: ABdhPJz6Kog9KdDxoSgGTpJDWYP0eNAr4wgdNbABfCWGwzNAmLS8QhURq0jOW8u0wHDKrkn7AA/nsg== X-Received: by 2002:adf:f4d2:: with SMTP id h18mr28063492wrp.370.1592212417436; Mon, 15 Jun 2020 02:13:37 -0700 (PDT) Received: from localhost (ip-37-188-174-201.eurotel.cz. [37.188.174.201]) by smtp.gmail.com with ESMTPSA id k14sm22725615wrq.97.2020.06.15.02.13.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Jun 2020 02:13:36 -0700 (PDT) Date: Mon, 15 Jun 2020 11:13:35 +0200 From: Michal Hocko To: Muchun Song Cc: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Roman Gushchin Subject: Re: [PATCH] mm/slab: Add a __GFP_ACCOUNT GFP flag check for slab allocation Message-ID: <20200615091335.GD25296@dhcp22.suse.cz> References: <20200614063858.85118-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200614063858.85118-1-songmuchun@bytedance.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Cc Roman] On Sun 14-06-20 14:38:58, Muchun Song wrote: > When a kmem_cache is initialized with SLAB_ACCOUNT slab flag, we must > not call kmem_cache_alloc with __GFP_ACCOUNT GFP flag. In this case, > we can be accounted to kmemcg twice. This is not correct. So we add a > __GFP_ACCOUNT GFP flag check for slab allocation. > > We also introduce a new helper named fixup_gfp_flags to do that check. > We can reuse the fixup_gfp_flags for SLAB/SLUB. > > Signed-off-by: Muchun Song > --- > mm/slab.c | 10 +--------- > mm/slab.h | 21 +++++++++++++++++++++ > mm/slub.c | 10 +--------- > 3 files changed, 23 insertions(+), 18 deletions(-) > > diff --git a/mm/slab.c b/mm/slab.c > index 9350062ffc1a..6e0110bef2d6 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -126,8 +126,6 @@ > > #include > > -#include "internal.h" > - > #include "slab.h" > > /* > @@ -2579,13 +2577,7 @@ static struct page *cache_grow_begin(struct kmem_cache *cachep, > * Be lazy and only check for valid flags here, keeping it out of the > * critical path in kmem_cache_alloc(). > */ > - if (unlikely(flags & GFP_SLAB_BUG_MASK)) { > - gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; > - flags &= ~GFP_SLAB_BUG_MASK; > - pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", > - invalid_mask, &invalid_mask, flags, &flags); > - dump_stack(); > - } > + flags = fixup_gfp_flags(cachep, flags); > WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO)); > local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); > > diff --git a/mm/slab.h b/mm/slab.h > index 815e4e9a94cd..0b91f2a7b033 100644 > --- a/mm/slab.h > +++ b/mm/slab.h > @@ -109,6 +109,7 @@ struct memcg_cache_params { > #include > #include > #include > +#include "internal.h" > > /* > * State of the slab allocator. > @@ -627,6 +628,26 @@ struct kmem_cache_node { > > }; > > +static inline gfp_t fixup_gfp_flags(struct kmem_cache *s, gfp_t flags) > +{ > + gfp_t invalid_mask = 0; > + > + if (unlikely(flags & GFP_SLAB_BUG_MASK)) > + invalid_mask |= flags & GFP_SLAB_BUG_MASK; > + > + if (unlikely(flags & __GFP_ACCOUNT && s->flags & SLAB_ACCOUNT)) > + invalid_mask |= __GFP_ACCOUNT; > + > + if (unlikely(invalid_mask)) { > + flags &= ~invalid_mask; > + pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", > + invalid_mask, &invalid_mask, flags, &flags); > + dump_stack(); > + } > + > + return flags; > +} > + > static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) > { > return s->node[node]; > diff --git a/mm/slub.c b/mm/slub.c > index b8f798b50d44..49b5cb7da318 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -37,8 +37,6 @@ > > #include > > -#include "internal.h" > - > /* > * Lock order: > * 1. slab_mutex (Global Mutex) > @@ -1745,13 +1743,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) > > static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) > { > - if (unlikely(flags & GFP_SLAB_BUG_MASK)) { > - gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; > - flags &= ~GFP_SLAB_BUG_MASK; > - pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", > - invalid_mask, &invalid_mask, flags, &flags); > - dump_stack(); > - } > + flags = fixup_gfp_flags(s, flags); > > return allocate_slab(s, > flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node); > -- > 2.11.0 -- Michal Hocko SUSE Labs