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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 1E495C43331 for ; Thu, 2 Apr 2020 04:06:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D9523206E9 for ; Thu, 2 Apr 2020 04:06:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rIzWP9uX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9523206E9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 63C6F8E003C; Thu, 2 Apr 2020 00:06:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5EC728E000D; Thu, 2 Apr 2020 00:06:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5028D8E003C; Thu, 2 Apr 2020 00:06:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id 366C18E000D for ; Thu, 2 Apr 2020 00:06:32 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 09AAF181AC9CC for ; Thu, 2 Apr 2020 04:06:32 +0000 (UTC) X-FDA: 76661578224.10.rose83_38fff90b63d35 X-HE-Tag: rose83_38fff90b63d35 X-Filterd-Recvd-Size: 4455 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Apr 2020 04:06:31 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 91437206E9; Thu, 2 Apr 2020 04:06:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585800390; bh=XfZ+xfJzdnljJRhmQ9enIqeOGQ+guYQibLDPmv5p7UI=; h=Date:From:To:Subject:In-Reply-To:From; b=rIzWP9uXDHBYbUHqnlinvYDFbaQiTCQfWxkmaHxplFXAdrOkGpP7AQ1A4kCrw95P0 mH2XdbVV5nnilJ02pJChmrgE5KQfqlSvrHy10btg4Bexph/c1dvEScl9nmU4pLMVi/ xG0wMioTCn16mWId1wv5Zg/IQ6Mmwx+DOF88/7p0= Date: Wed, 01 Apr 2020 21:06:30 -0700 From: Andrew Morton To: akpm@linux-foundation.org, hannes@cmpxchg.org, laoar.shao@gmail.com, linux-mm@kvack.org, mhocko@kernel.org, mm-commits@vger.kernel.org, tj@kernel.org, torvalds@linux-foundation.org, vdavydov.dev@gmail.com Subject: [patch 060/155] mm, memcg: fix build error around the usage of kmem_caches Message-ID: <20200402040630.5wtvrtiGI%akpm@linux-foundation.org> In-Reply-To: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Yafang Shao Subject: mm, memcg: fix build error around the usage of kmem_caches When I manually set default n to MEMCG_KMEM in init/Kconfig, bellow error occurs, mm/slab_common.c: In function 'memcg_slab_start': mm/slab_common.c:1530:30: error: 'struct mem_cgroup' has no member named 'kmem_caches' return seq_list_start(&memcg->kmem_caches, *pos); ^ mm/slab_common.c: In function 'memcg_slab_next': mm/slab_common.c:1537:32: error: 'struct mem_cgroup' has no member named 'kmem_caches' return seq_list_next(p, &memcg->kmem_caches, pos); ^ mm/slab_common.c: In function 'memcg_slab_show': mm/slab_common.c:1551:16: error: 'struct mem_cgroup' has no member named 'kmem_caches' if (p == memcg->kmem_caches.next) ^ CC arch/x86/xen/smp.o mm/slab_common.c: In function 'memcg_slab_start': mm/slab_common.c:1531:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ mm/slab_common.c: In function 'memcg_slab_next': mm/slab_common.c:1538:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ That's because kmem_caches is defined only when CONFIG_MEMCG_KMEM is set, while memcg_slab_start() will use it no matter CONFIG_MEMCG_KMEM is defined or not. By the way, the reason I mannuly undefined CONFIG_MEMCG_KMEM is to verify whether my some other code change is still stable when CONFIG_MEMCG_KMEM is not set. Unfortunately, the existing code has been already unstable since v4.11. Link: http://lkml.kernel.org/r/1580970260-2045-1-git-send-email-laoar.shao@gmail.com Fixes: bc2791f857e1 ("slab: link memcg kmem_caches on their associated memory cgroup") Signed-off-by: Yafang Shao Acked-by: Andrew Morton Cc: Tejun Heo Cc: Vladimir Davydov Cc: Johannes Weiner Cc: Michal Hocko Signed-off-by: Andrew Morton --- mm/memcontrol.c | 3 ++- mm/slab_common.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) --- a/mm/memcontrol.c~mm-memcg-fix-build-error-around-the-usage-of-kmem_caches +++ a/mm/memcontrol.c @@ -4792,7 +4792,8 @@ static struct cftype mem_cgroup_legacy_f .write = mem_cgroup_reset, .read_u64 = mem_cgroup_read_u64, }, -#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) +#if defined(CONFIG_MEMCG_KMEM) && \ + (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) { .name = "kmem.slabinfo", .seq_start = memcg_slab_start, --- a/mm/slab_common.c~mm-memcg-fix-build-error-around-the-usage-of-kmem_caches +++ a/mm/slab_common.c @@ -1521,7 +1521,7 @@ void dump_unreclaimable_slab(void) mutex_unlock(&slab_mutex); } -#if defined(CONFIG_MEMCG) +#if defined(CONFIG_MEMCG_KMEM) void *memcg_slab_start(struct seq_file *m, loff_t *pos) { struct mem_cgroup *memcg = mem_cgroup_from_seq(m); _