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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL 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 31548C433DF for ; Fri, 31 Jul 2020 03:18:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AF21207F5 for ; Fri, 31 Jul 2020 03:18:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lAKSCIQ2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731261AbgGaDSH (ORCPT ); Thu, 30 Jul 2020 23:18:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730820AbgGaDSG (ORCPT ); Thu, 30 Jul 2020 23:18:06 -0400 Received: from mail-qk1-x736.google.com (mail-qk1-x736.google.com [IPv6:2607:f8b0:4864:20::736]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 975D7C061574 for ; Thu, 30 Jul 2020 20:18:06 -0700 (PDT) Received: by mail-qk1-x736.google.com with SMTP id b79so27595749qkg.9 for ; Thu, 30 Jul 2020 20:18:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:user-agent:mime-version; bh=SR7+yosq1xp0zigF9l1fWsxuDY4XPAok3oMTFmLnUZc=; b=lAKSCIQ2Rm1+s3DGdgW2sY0SDCmsMzaowSi7+qudL2dAuv8GkPJze1HW+crvQ6Bhfa bkM2/M1ClQC6+0080PfNkgGwgB0AbZq1JsoB8c9CImd523NXd9fNcPWF/5YNjMQICD+Y kpXpwM+1wPiFvPABKKPQUbIdDPsEOsUfphQLlmbyxkGOBWAQLsXXp9GEM5eDp82hPbZa EOQ+UK60Akrhw6dGGA7YbsemwJu5TM6rh1aIzwbI1wpgfC3+fSULumcTUeCrc0DAOzpZ TL+Y5mNy6ctfeP06zq+RB2wSm63t5aiEvC4e2SEf0ZVyRmmnHq+taF6/YOWS4xqjrBAf gmQA== 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:user-agent :mime-version; bh=SR7+yosq1xp0zigF9l1fWsxuDY4XPAok3oMTFmLnUZc=; b=Ox6l1lcj03gLazP73N7hfeKcJvMi8uSQuOSZE/N/xMsBQF55Inn+4aoJ8qdAnwNfzj m5AEE4SmQt6ShwayjXbkQshaYWFB65ivJa2yKNQj2VG54p6eaCwTygYiT0bx4pyzqe7P q4C+qdFYYq09OdkarzltwfDTAkKbv0J0wv2OhRpdiJOmT8mKCkrzkxdUskuB+P0YOryg MP4Lbj6pSixyfhw08yvO4MjO/OQ4gi6yClo/A2jDjp6WuUTxQlFS9NehAsBRsBjM4xWx 8U/0kcMobgW/NYU6oKFigXpWzCE0pZt2iJhE8gu7cuFDPGAqTDlZx/TZy3T+0EXL+BRO lE3g== X-Gm-Message-State: AOAM530AW96nY6p3JUZbw1dZ8+JqehQLKOaBOGcbJL82W1x70R16PCRV CLdfrjJgaHzYysosLDxFDkdbWg== X-Google-Smtp-Source: ABdhPJwDwQt3K/iTgMokrKbRI7xWY04eq/mt5E9rmbuM1E79HWT25mrsITLMlCNlT8E1q0fjShonhQ== X-Received: by 2002:a05:620a:1424:: with SMTP id k4mr2210742qkj.2.1596165485326; Thu, 30 Jul 2020 20:18:05 -0700 (PDT) Received: from eggly.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id s38sm7256566qts.78.2020.07.30.20.18.03 (version=TLS1 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Thu, 30 Jul 2020 20:18:04 -0700 (PDT) Date: Thu, 30 Jul 2020 20:17:50 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Andrew Morton cc: Roman Gushchin , Johannes Weiner , Shakeel Butt , Hugh Dickins , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH mmotm] mm: memcontrol: decouple reference counting from page accounting fix Message-ID: User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Moving tasks between mem cgroups with memory.move_charge_at_immigrate 3, while swapping, crashes soon on mmotm (and so presumably on linux-next): for example, spinlock found corrupted when lock_page_memcg() is called. It's as if the mem cgroup structures have been freed too early. Stab in the dark: what if all the accounting is right, except that the css_put_many() in __mem_cgroup_clear_mc() is now (worse than) redundant? Removing it fixes the crashes, but that's hardly surprising; and stats temporarily hacked into mem_cgroup_css_alloc() and mem_cgroup_css_free() showed that mem cgroups were not being leaked with this change. Note: this removes the last call to css_put_many() from the tree; and mm-memcg-slab-use-a-single-set-of-kmem_caches-for-all-accounted-allocations.patch removes the last call to css_get_many(): now that their last references have gone, I expect them soon to be freed from include/linux/cgroup.h. Signed-off-by: Hugh Dickins --- Fixes mm-memcontrol-decouple-reference-counting-from-page-accounting.patch mm/memcontrol.c | 2 -- 1 file changed, 2 deletions(-) --- mmotm/mm/memcontrol.c 2020-07-27 18:55:00.700554752 -0700 +++ linux/mm/memcontrol.c 2020-07-30 12:05:00.640091618 -0700 @@ -5887,8 +5887,6 @@ static void __mem_cgroup_clear_mc(void) if (!mem_cgroup_is_root(mc.to)) page_counter_uncharge(&mc.to->memory, mc.moved_swap); - css_put_many(&mc.to->css, mc.moved_swap); - mc.moved_swap = 0; } memcg_oom_recover(from); 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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL autolearn=ham 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 5C64AC433E0 for ; Fri, 31 Jul 2020 03:18:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1663D207F5 for ; Fri, 31 Jul 2020 03:18:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lAKSCIQ2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1663D207F5 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 87B438D0010; Thu, 30 Jul 2020 23:18:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 82DA98D000B; Thu, 30 Jul 2020 23:18:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 719DB8D0010; Thu, 30 Jul 2020 23:18:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0229.hostedemail.com [216.40.44.229]) by kanga.kvack.org (Postfix) with ESMTP id 5CB748D000B for ; Thu, 30 Jul 2020 23:18:07 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 080A5181AEF09 for ; Fri, 31 Jul 2020 03:18:07 +0000 (UTC) X-FDA: 77096912214.17.queen37_0b09a3226f80 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id A3F50180D0185 for ; Fri, 31 Jul 2020 03:18:06 +0000 (UTC) X-HE-Tag: queen37_0b09a3226f80 X-Filterd-Recvd-Size: 4482 Received: from mail-qk1-f169.google.com (mail-qk1-f169.google.com [209.85.222.169]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Fri, 31 Jul 2020 03:18:06 +0000 (UTC) Received: by mail-qk1-f169.google.com with SMTP id g26so27688588qka.3 for ; Thu, 30 Jul 2020 20:18:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:user-agent:mime-version; bh=SR7+yosq1xp0zigF9l1fWsxuDY4XPAok3oMTFmLnUZc=; b=lAKSCIQ2Rm1+s3DGdgW2sY0SDCmsMzaowSi7+qudL2dAuv8GkPJze1HW+crvQ6Bhfa bkM2/M1ClQC6+0080PfNkgGwgB0AbZq1JsoB8c9CImd523NXd9fNcPWF/5YNjMQICD+Y kpXpwM+1wPiFvPABKKPQUbIdDPsEOsUfphQLlmbyxkGOBWAQLsXXp9GEM5eDp82hPbZa EOQ+UK60Akrhw6dGGA7YbsemwJu5TM6rh1aIzwbI1wpgfC3+fSULumcTUeCrc0DAOzpZ TL+Y5mNy6ctfeP06zq+RB2wSm63t5aiEvC4e2SEf0ZVyRmmnHq+taF6/YOWS4xqjrBAf gmQA== 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:user-agent :mime-version; bh=SR7+yosq1xp0zigF9l1fWsxuDY4XPAok3oMTFmLnUZc=; b=buFVHzxQY431dqpuBOi91gsqE9Y2I3nfYQ/QH7C0MZ/7aWqJ9deMYU/4maVl3GBE4H 4PYktoVit4Whd4l8+/Am3VJFhNSnWkKuWPHbPO8zgiXsH+h+0UUaAoT+0X1qXS89R1DT o+Amh0+AKOGvOzdrQAe/+I+4e9mQ6oBSpCSZcrEJDHUmQa8ecwMchYVjDz7WLOzonYOQ +X64uHBPZUO27fjDXau63PbPIjO84vi5Nh3UrWqxx+Oc3NnAJu+kEPuQ7DhdSGJJ0zFV w+TfIg777xuaTP/w6PWnM4VKreWsB0PK9SjOJY+vYJzxj0LMDSH0doyCDnfkzz/29uzq bhRg== X-Gm-Message-State: AOAM5326omAxI+WEg8becjxDjlHOGLciJcbUfTOVqCNwj2Cj4k3lrbRI t2ixVm1r1BSZcXSIm0RwA1Bovg== X-Google-Smtp-Source: ABdhPJwDwQt3K/iTgMokrKbRI7xWY04eq/mt5E9rmbuM1E79HWT25mrsITLMlCNlT8E1q0fjShonhQ== X-Received: by 2002:a05:620a:1424:: with SMTP id k4mr2210742qkj.2.1596165485326; Thu, 30 Jul 2020 20:18:05 -0700 (PDT) Received: from eggly.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id s38sm7256566qts.78.2020.07.30.20.18.03 (version=TLS1 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Thu, 30 Jul 2020 20:18:04 -0700 (PDT) Date: Thu, 30 Jul 2020 20:17:50 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Andrew Morton cc: Roman Gushchin , Johannes Weiner , Shakeel Butt , Hugh Dickins , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH mmotm] mm: memcontrol: decouple reference counting from page accounting fix Message-ID: User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Rspamd-Queue-Id: A3F50180D0185 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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: Moving tasks between mem cgroups with memory.move_charge_at_immigrate 3, while swapping, crashes soon on mmotm (and so presumably on linux-next): for example, spinlock found corrupted when lock_page_memcg() is called. It's as if the mem cgroup structures have been freed too early. Stab in the dark: what if all the accounting is right, except that the css_put_many() in __mem_cgroup_clear_mc() is now (worse than) redundant? Removing it fixes the crashes, but that's hardly surprising; and stats temporarily hacked into mem_cgroup_css_alloc() and mem_cgroup_css_free() showed that mem cgroups were not being leaked with this change. Note: this removes the last call to css_put_many() from the tree; and mm-memcg-slab-use-a-single-set-of-kmem_caches-for-all-accounted-allocations.patch removes the last call to css_get_many(): now that their last references have gone, I expect them soon to be freed from include/linux/cgroup.h. Signed-off-by: Hugh Dickins --- Fixes mm-memcontrol-decouple-reference-counting-from-page-accounting.patch mm/memcontrol.c | 2 -- 1 file changed, 2 deletions(-) --- mmotm/mm/memcontrol.c 2020-07-27 18:55:00.700554752 -0700 +++ linux/mm/memcontrol.c 2020-07-30 12:05:00.640091618 -0700 @@ -5887,8 +5887,6 @@ static void __mem_cgroup_clear_mc(void) if (!mem_cgroup_is_root(mc.to)) page_counter_uncharge(&mc.to->memory, mc.moved_swap); - css_put_many(&mc.to->css, mc.moved_swap); - mc.moved_swap = 0; } memcg_oom_recover(from);