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=-6.8 required=3.0 tests=BAYES_00,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 AA015C388F2 for ; Wed, 4 Nov 2020 03:04:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7241A223FB for ; Wed, 4 Nov 2020 03:04:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604459055; bh=D4z0GHUzSVzy/tRoA6QhUS9W5omZ4Yrof5aelO0r3HM=; h=Date:From:To:Subject:Reply-To:List-ID:From; b=MlxM3HK+9BWFCUbew1fB0KCg4YGzukICdt2G47MKqAMXd8NLoAJlna2dAdTL9RAjY VRTBW6kC/yovZ2PZL3feRMxx9ERhD0wo1i0V0z+M9sp6HrNkRaLTmRgF9B4gwRqDAK jFUwTgaq3yWvxC4xF1I1Kfeb5X8uzlqUEVXbgpxY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729801AbgKDDEP (ORCPT ); Tue, 3 Nov 2020 22:04:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:48016 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728972AbgKDDEO (ORCPT ); Tue, 3 Nov 2020 22:04:14 -0500 Received: from X1 (unknown [208.106.6.120]) (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 A06E9223BF; Wed, 4 Nov 2020 03:04:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604459053; bh=D4z0GHUzSVzy/tRoA6QhUS9W5omZ4Yrof5aelO0r3HM=; h=Date:From:To:Subject:From; b=uJZjKJBL534ZjnUBIt0nDkZy6D/KfoDpYydPaSXe5xBoTfDr78LfbmLpb9tn6nCKO Kz/sVoFOy2R0XsArdLuj9OfLeDCuY0eHy+2vtMnoStyJA6vgyPE6UqXec6JkPTYIUB HH4bNka8rd61WKLutDw4paF8vX0mF4czJmg58+SI= Date: Tue, 03 Nov 2020 19:04:10 -0800 From: akpm@linux-foundation.org To: mm-commits@vger.kernel.org, vdavydov.dev@gmail.com, mhocko@suse.com, hughd@google.com, hannes@cmpxchg.org, alex.shi@linux.alibaba.com Subject: + mm-memcg-warning-on-memcg-after-readahead-page-charged.patch added to -mm tree Message-ID: <20201104030410.L_EwI%akpm@linux-foundation.org> User-Agent: s-nail v14.9.10 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/memcg: warning on !memcg after readahead page charged has been added to the -mm tree. Its filename is mm-memcg-warning-on-memcg-after-readahead-page-charged.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-warning-on-memcg-after-readahead-page-charged.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-warning-on-memcg-after-readahead-page-charged.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Alex Shi Subject: mm/memcg: warning on !memcg after readahead page charged Add VM_WARN_ON_ONCE_PAGE() macro. Since readahead page is charged on memcg too, in theory we don't have to check this exception now. Before safely remove them all, add a warning for the unexpected !memcg. Link: https://lkml.kernel.org/r/1604283436-18880-3-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi Acked-by: Michal Hocko Acked-by: Hugh Dickins Acked-by: Johannes Weiner Cc: Vladimir Davydov Signed-off-by: Andrew Morton --- include/linux/mmdebug.h | 13 +++++++++++++ mm/memcontrol.c | 10 ++++------ 2 files changed, 17 insertions(+), 6 deletions(-) --- a/include/linux/mmdebug.h~mm-memcg-warning-on-memcg-after-readahead-page-charged +++ a/include/linux/mmdebug.h @@ -37,6 +37,18 @@ void dump_mm(const struct mm_struct *mm) BUG(); \ } \ } while (0) +#define VM_WARN_ON_ONCE_PAGE(cond, page) ({ \ + static bool __section(".data.once") __warned; \ + int __ret_warn_once = !!(cond); \ + \ + if (unlikely(__ret_warn_once && !__warned)) { \ + dump_page(page, "VM_WARN_ON_ONCE_PAGE(" __stringify(cond)")");\ + __warned = true; \ + WARN_ON(1); \ + } \ + unlikely(__ret_warn_once); \ +}) + #define VM_WARN_ON(cond) (void)WARN_ON(cond) #define VM_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond) #define VM_WARN_ONCE(cond, format...) (void)WARN_ONCE(cond, format) @@ -48,6 +60,7 @@ void dump_mm(const struct mm_struct *mm) #define VM_BUG_ON_MM(cond, mm) VM_BUG_ON(cond) #define VM_WARN_ON(cond) BUILD_BUG_ON_INVALID(cond) #define VM_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond) +#define VM_WARN_ON_ONCE_PAGE(cond, page) BUILD_BUG_ON_INVALID(cond) #define VM_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond) #define VM_WARN(cond, format...) BUILD_BUG_ON_INVALID(cond) #endif --- a/mm/memcontrol.c~mm-memcg-warning-on-memcg-after-readahead-page-charged +++ a/mm/memcontrol.c @@ -1325,10 +1325,7 @@ struct lruvec *mem_cgroup_page_lruvec(st } memcg = page_memcg(page); - /* - * Swapcache readahead pages are added to the LRU - and - * possibly migrated - before they are charged. - */ + VM_WARN_ON_ONCE_PAGE(!memcg, page); if (!memcg) memcg = root_mem_cgroup; @@ -6966,6 +6963,7 @@ void mem_cgroup_migrate(struct page *old /* Swapcache readahead pages can get replaced before being charged */ memcg = page_memcg(oldpage); + VM_WARN_ON_ONCE_PAGE(!memcg, oldpage); if (!memcg) return; @@ -7165,7 +7163,7 @@ void mem_cgroup_swapout(struct page *pag memcg = page_memcg(page); - /* Readahead page, never charged */ + VM_WARN_ON_ONCE_PAGE(!memcg, page); if (!memcg) return; @@ -7232,7 +7230,7 @@ int mem_cgroup_try_charge_swap(struct pa memcg = page_memcg(page); - /* Readahead page, never charged */ + VM_WARN_ON_ONCE_PAGE(!memcg, page); if (!memcg) return 0; _ Patches currently in -mm which might be from alex.shi@linux.alibaba.com are mm-memcg-bail-early-from-swap-accounting-if-memcg-disabled.patch mm-memcg-warning-on-memcg-after-readahead-page-charged.patch