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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F42EC433F5 for ; Mon, 28 Mar 2022 07:02:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 65E4A8D0002; Mon, 28 Mar 2022 03:02:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 60E538D0001; Mon, 28 Mar 2022 03:02:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4FD458D0002; Mon, 28 Mar 2022 03:02:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 4189A8D0001 for ; Mon, 28 Mar 2022 03:02:34 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id F26FA616AB for ; Mon, 28 Mar 2022 07:02:33 +0000 (UTC) X-FDA: 79292901828.04.6D6C544 Received: from mail-yb1-f170.google.com (mail-yb1-f170.google.com [209.85.219.170]) by imf03.hostedemail.com (Postfix) with ESMTP id 716392003B for ; Mon, 28 Mar 2022 07:02:33 +0000 (UTC) Received: by mail-yb1-f170.google.com with SMTP id u103so24365840ybi.9 for ; Mon, 28 Mar 2022 00:02:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=nwxetPNc6Y1ndBg59v0qTwqCMW+RX+QXtDxwiYX/QcY=; b=oQjYl0VWVU8kxZqRgLrRJylBYKDAfu2P+MqJrikBOY4cYgVZRJuXh8PdhrRvsx5++q OC2NMTK7wrbpFIDA2F+JIYQIk2/Hfd7h3Szj8FAeuuu3AtvVdUvQ5LL5j5tRQBvAy/U5 EW2xcOkTOTcPsgqfjVzFip9g7drZlmsjIVxbnww2gYiJTBfCoZurMqDp+qgYQJ2Rrtnx PKZfISDr69xp+ybvl1fNeBAbi89uVkLWdSx0lJlkPwe6CO7INN7AdobyGpxxaDe75Wio 6+29D3AxsbKcHgwZPQf2GPiq4lJYoM7L5cC61ayZvFSac85w0odjhCONYIqGbjSS0EAK mRWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=nwxetPNc6Y1ndBg59v0qTwqCMW+RX+QXtDxwiYX/QcY=; b=ei7Q420KlWz0TP/Tn0tek6WEATbVzkumT+gMQVPii0cvbsebgWq9RpDB6F4iA1LsT1 H4lTGYCGSZn2ApDQfalzLLKQdw73RbkXWNcpM5ImupSPLuzC2h6GesYvWfAZDZrz8Rp2 KC67Uf+6GY4B8rpfOPbkaT6JB1iq9f5gGrMO3mGwutsSrTUfNeAB3+Jqh0jmRAnWq9ka Jv8kO9ELmoWVa+wQy6QlEag/sigCzjDP5JlG/w63pZ1WeTXPn8xUiHcxmm1g+bVGv5vD 91drOfruCef/jOBATvVpiAble2ZdGiKL3P73BouA5IGQDjd6tpqiCgJh3701GhyjAmOF kNaA== X-Gm-Message-State: AOAM530B5C81P+48wccDlrSFDVC+xpmxVSXUkW2N614ngJm1BUCiyNPU bc541JXwnvUX7f5UxPKltyeR1KrqgAoQcii8Ydsafw== X-Google-Smtp-Source: ABdhPJy73Qtx0ny5VqjuQuHNLFzET7+MEl9kPFj+10ogu4maeklF3JBd4rEFNfkBXoJI3+0sReG34wOW+F5JBMo6XnU= X-Received: by 2002:a25:d08a:0:b0:633:eba2:e487 with SMTP id h132-20020a25d08a000000b00633eba2e487mr20846788ybg.609.1648450952327; Mon, 28 Mar 2022 00:02:32 -0700 (PDT) MIME-Version: 1.0 References: <20220327051853.57647-1-songmuchun@bytedance.com> <20220327051853.57647-2-songmuchun@bytedance.com> In-Reply-To: From: Marco Elver Date: Mon, 28 Mar 2022 09:01:55 +0200 Message-ID: Subject: Re: [PATCH 2/2] mm: kfence: fix objcgs vector allocation To: Muchun Song Cc: Linus Torvalds , Alexander Potapenko , Dmitry Vyukov , Andrew Morton , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin , kasan-dev , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 716392003B X-Stat-Signature: emrtdmwzu1j75es8p3a538z1o6f55u8e X-Rspam-User: Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=oQjYl0VW; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf03.hostedemail.com: domain of elver@google.com designates 209.85.219.170 as permitted sender) smtp.mailfrom=elver@google.com X-HE-Tag: 1648450953-399414 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 28 Mar 2022 at 03:53, Muchun Song wrote: > > On Mon, Mar 28, 2022 at 1:31 AM Marco Elver wrote: > > > > On Sun, 27 Mar 2022 at 07:19, Muchun Song wrote: > > > > > > If the kfence object is allocated to be used for objects vector, then > > > this slot of the pool eventually being occupied permanently since > > > the vector is never freed. The solutions could be 1) freeing vector > > > when the kfence object is freed or 2) allocating all vectors statically. > > > Since the memory consumption of object vectors is low, it is better to > > > chose 2) to fix the issue and it is also can reduce overhead of vectors > > > allocating in the future. > > > > > > Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB") > > > Signed-off-by: Muchun Song > > > --- > > > mm/kfence/core.c | 3 +++ > > > mm/kfence/kfence.h | 1 + > > > 2 files changed, 4 insertions(+) > > > > Thanks for this -- mostly looks good. Minor comments below + also > > please fix what the test robot reported. > > Will do. > > > > > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > > > index 13128fa13062..9976b3f0d097 100644 > > > --- a/mm/kfence/core.c > > > +++ b/mm/kfence/core.c > > > @@ -579,9 +579,11 @@ static bool __init kfence_init_pool(void) > > > } > > > > > > for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) { > > > + struct slab *slab = virt_to_slab(addr); > > > struct kfence_metadata *meta = &kfence_metadata[i]; > > > > > > /* Initialize metadata. */ > > > + slab->memcg_data = (unsigned long)&meta->objcg | MEMCG_DATA_OBJCGS; > > > > Maybe just move it to kfence_guarded_alloc(), see "/* Set required > > slab fields */", where similar initialization on slab is done. > > But slab->memcg_data is special since it is only needed to be > initialized once. I think it is better move it to the place where > __SetPageSlab(&pages[i]) is. What do you think? That's fair.