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 58E24C433F5 for ; Mon, 28 Mar 2022 19:26:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id ADDDF8D0002; Mon, 28 Mar 2022 15:26:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A8D788D0001; Mon, 28 Mar 2022 15:26:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 92EA98D0002; Mon, 28 Mar 2022 15:26:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 7E9A28D0001 for ; Mon, 28 Mar 2022 15:26:10 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 39411213DD for ; Mon, 28 Mar 2022 19:26:10 +0000 (UTC) X-FDA: 79294775700.14.E5DAC9E Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by imf09.hostedemail.com (Postfix) with ESMTP id 39101140033 for ; Mon, 28 Mar 2022 19:26:09 +0000 (UTC) Date: Mon, 28 Mar 2022 12:26:02 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1648495567; 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: in-reply-to:in-reply-to:references:references; bh=HI+dsvmjaN/rkGaZbNLF+cKlPT7DGdpfJYFLeEXc0Ts=; b=jpOSnpVGPf5/gLaSmGsNc0vn5N+hBHUR9ky2eGwEPwKeNEvqUDPzzpVpElXTK/7f/6q5Le tMd6dnJTD9Q1coxYQspQN9x0xJsA/tLuqTgnm4C8ado5C/3SWuMh6pO0nLk9xPmTr7SYeL 5NECd/RNfvdD7AVIFQwhXx4BEP33vzU= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Roman Gushchin To: Muchun Song Cc: glider@google.com, elver@google.com, dvyukov@google.com, akpm@linux-foundation.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, duanxiongchun@bytedance.com Subject: Re: [PATCH v2] mm: kfence: fix objcgs vector allocation Message-ID: References: <20220328132843.16624-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220328132843.16624-1-songmuchun@bytedance.com> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 39101140033 X-Stat-Signature: bgjdmdbygt89c96cy7y6dq6qkffacex9 X-Rspam-User: Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=jpOSnpVG; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf09.hostedemail.com: domain of roman.gushchin@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev X-HE-Tag: 1648495569-705021 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, Mar 28, 2022 at 09:28:43PM +0800, 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 > --- > v2: > - Fix compiler error reported by kernel test robot . Reviewed-by: Roman Gushchin LGTM, thanks! > > mm/kfence/core.c | 11 ++++++++++- > mm/kfence/kfence.h | 3 +++ > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > index 13128fa13062..d4c7978cd75e 100644 > --- a/mm/kfence/core.c > +++ b/mm/kfence/core.c > @@ -555,6 +555,8 @@ static bool __init kfence_init_pool(void) > * enters __slab_free() slow-path. > */ > for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) { > + struct slab *slab = page_slab(&pages[i]); > + > if (!i || (i % 2)) > continue; > > @@ -562,7 +564,11 @@ static bool __init kfence_init_pool(void) > if (WARN_ON(compound_head(&pages[i]) != &pages[i])) > goto err; > > - __SetPageSlab(&pages[i]); > + __folio_set_slab(slab_folio(slab)); > +#ifdef CONFIG_MEMCG > + slab->memcg_data = (unsigned long)&kfence_metadata[i / 2 - 1].objcg | > + MEMCG_DATA_OBJCGS; > +#endif We can probably put CONFIG_MEMCG_KMEM here, but it doesn't matter that much. In the long run we should get rid of CONFIG_MEMCG_KMEM anyway.