From nobody Wed Feb 11 08:12:22 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C616C761A6 for ; Wed, 5 Apr 2023 11:01:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237680AbjDELBd (ORCPT ); Wed, 5 Apr 2023 07:01:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237270AbjDELB1 (ORCPT ); Wed, 5 Apr 2023 07:01:27 -0400 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90A3C46B2; Wed, 5 Apr 2023 04:01:25 -0700 (PDT) Received: by mail-pj1-x1032.google.com with SMTP id lr16-20020a17090b4b9000b0023f187954acso36866841pjb.2; Wed, 05 Apr 2023 04:01:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680692485; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=iJGAMvCER1Maz71WC4+d0+uJtDiWgp7hdUA5ioSAboA=; b=hEwXkknLt4/QXa+iW0HAL1xHl2WxZgLYRd25Wix9ug2M31GthLBb2gQ6B1KHAgXFRk Hh56NWJFg7+Ht4moggFzSw48UXB8Sk/EUlNXy3uuEjfN3DVjZL0pVD+8lW7VP91OxaLE 61bF6FVt4o7Lhk88ghkElEEb7JR5ZiCEV3Ij681bdG2GeGtONm1VNGG+6R5zvKPW6+Gb Bck/Qui9VdXuYTqFW9edEpdO35H9mHE1rAS8wbKxe/PmbsBhwdlHt6Kk0T3+3uuwiRdq lmfbu6GhcYExWgxYgtFlDtBOVC5pTlLRWAYTf3t/iwF8FUi5Jk+5cxvW89+5FeG2KmE2 fhPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680692485; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=iJGAMvCER1Maz71WC4+d0+uJtDiWgp7hdUA5ioSAboA=; b=tBizntVRLlLVmZTe6Mr3P1wwgXuKR3Z1pSN9H6WyBXRjvUgOBXKW0fYRgQAJRJKM/g GhgTZViMhXR7h3EOJS7PEk0VH+58h5TUs9Im+rnnKaL7XuBZPqHkOYBGXtnvXTmoKaiI yAehwvBC+fyGiDtkz1gZwSiiPE2TLy/aqdSXNUcC8sqCCrP4wIiayklmkTlTtc1YtuGw Cd5hZIYCDXR1UwVk3E9E30KwAdeFvemvPF/cVFq+sblwwXL00BKna3nWex9NKUCmvEXY riOv5qdOA4/lqbOz8X15jgJW+RqFSSSeNM9OV5qCKihD7wvzJ/QVTsO69lCsUQHvQWdE S9vw== X-Gm-Message-State: AAQBX9fpTl3aWz4b0CNvFI0THOX04s9WFG/UMphy2zpvHvdXM0MYzIbw Q6DYtZhOd39LiWKPtsP/NTA= X-Google-Smtp-Source: AKy350YwlKoCBpiBymdY26Utiux0aRqLnTsThq8o6n5gNgRGHnQlVHaic+BuLQMT7CE0kVxzyTniAQ== X-Received: by 2002:a17:90b:1b09:b0:237:f925:f63 with SMTP id nu9-20020a17090b1b0900b00237f9250f63mr6383415pjb.13.1680692484650; Wed, 05 Apr 2023 04:01:24 -0700 (PDT) Received: from lunar.aeonazure.com ([182.2.143.216]) by smtp.gmail.com with ESMTPSA id f11-20020a17090274cb00b001a065d3bb0esm9831373plt.211.2023.04.05.04.01.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Apr 2023 04:01:24 -0700 (PDT) From: Shaun Tancheff To: Johannes Weiner , Michal Hocko , Vladimir Davydov Cc: Shaun Tancheff , Andrew Morton , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH] memcg-v1: Enable setting memory min, low, high Date: Wed, 5 Apr 2023 18:01:07 +0700 Message-Id: <20230405110107.127156-1-shaun.tancheff@gmail.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Shaun Tancheff For users that are unable to update to memcg-v2 this provides a method where memcg-v1 can more effectively apply enough memory pressure to effectively throttle filesystem I/O or otherwise minimize being memcg oom killed at the expense of reduced performance. This patch extends the memcg-v1 legacy sysfs entries with: limit_in_bytes.min, limit_in_bytes.low and limit_in_bytes.high Since old software will need to be updated to take advantage of the new files a secondary method of setting min, low and high based on a percentage of the limit is also provided. The percentages are determined by module parameters. The available module parameters can be set at kernel boot time, for example: memcontrol.memcg_min=3D10 memcontrol.memcg_low=3D30 memcontrol.memcg_high=3D80 Would set min to 10%, low to 30% and high to 80% of the value written to: /sys/fs/cgroup/memory//memory.limit_in_bytes Signed-off-by: Shaun Tancheff --- v0: Initial hard coded limits by percent. v1: Added sysfs access and module parameters for percent values to enable v2: Fix 32-bit, remove need for missing __udivdi3 mm/memcontrol.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 82 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2eee092f8f11..3cf8386f4f45 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -73,6 +73,18 @@ =20 #include =20 +static unsigned int memcg_v1_min_default_percent; +module_param_named(memcg_min, memcg_v1_min_default_percent, uint, 0600); +MODULE_PARM_DESC(memcg_min, "memcg v1 min default percent"); + +static unsigned int memcg_v1_low_default_percent; +module_param_named(memcg_low, memcg_v1_low_default_percent, uint, 0600); +MODULE_PARM_DESC(memcg_low, "memcg v1 low default percent"); + +static unsigned int memcg_v1_high_default_percent; +module_param_named(memcg_high, memcg_v1_high_default_percent, uint, 0600); +MODULE_PARM_DESC(memcg_high, "memcg v1 high default percent"); + struct cgroup_subsys memory_cgrp_subsys __read_mostly; EXPORT_SYMBOL(memory_cgrp_subsys); =20 @@ -205,6 +217,7 @@ enum res_type { _MEMSWAP, _KMEM, _TCP, + _MEM_V1, }; =20 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) @@ -3676,6 +3689,9 @@ enum { RES_MAX_USAGE, RES_FAILCNT, RES_SOFT_LIMIT, + RES_LIMIT_MIN, + RES_LIMIT_LOW, + RES_LIMIT_HIGH, }; =20 static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, @@ -3686,6 +3702,7 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_s= tate *css, =20 switch (MEMFILE_TYPE(cft->private)) { case _MEM: + case _MEM_V1: counter =3D &memcg->memory; break; case _MEMSWAP: @@ -3716,6 +3733,12 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_= state *css, return counter->failcnt; case RES_SOFT_LIMIT: return (u64)memcg->soft_limit * PAGE_SIZE; + case RES_LIMIT_MIN: + return (u64)READ_ONCE(memcg->memory.min); + case RES_LIMIT_LOW: + return (u64)READ_ONCE(memcg->memory.low); + case RES_LIMIT_HIGH: + return (u64)READ_ONCE(memcg->memory.high); default: BUG(); } @@ -3815,6 +3838,34 @@ static int memcg_update_tcp_max(struct mem_cgroup *m= emcg, unsigned long max) return ret; } =20 +static inline void mem_cgroup_v1_set_defaults(struct mem_cgroup *memcg, + unsigned long nr_pages) +{ + unsigned long min, low, high; + + if (mem_cgroup_is_root(memcg) || PAGE_COUNTER_MAX =3D=3D nr_pages) + return; + + min =3D READ_ONCE(memcg->memory.min); + low =3D READ_ONCE(memcg->memory.low); + if (min || low) + return; + + if (!min && memcg_v1_min_default_percent) { + min =3D (nr_pages * memcg_v1_min_default_percent) / 100; + page_counter_set_min(&memcg->memory, min); + } + if (!low && memcg_v1_low_default_percent) { + low =3D (nr_pages * memcg_v1_low_default_percent) / 100; + page_counter_set_low(&memcg->memory, low); + } + high =3D READ_ONCE(memcg->memory.high); + if (high =3D=3D PAGE_COUNTER_MAX && memcg_v1_high_default_percent) { + high =3D (nr_pages * memcg_v1_high_default_percent) / 100; + page_counter_set_high(&memcg->memory, high); + } +} + /* * The user of this function is... * RES_LIMIT. @@ -3838,6 +3889,11 @@ static ssize_t mem_cgroup_write(struct kernfs_open_f= ile *of, break; } switch (MEMFILE_TYPE(of_cft(of)->private)) { + case _MEM_V1: + ret =3D mem_cgroup_resize_max(memcg, nr_pages, false); + if (!ret) + mem_cgroup_v1_set_defaults(memcg, nr_pages); + break; case _MEM: ret =3D mem_cgroup_resize_max(memcg, nr_pages, false); break; @@ -4986,6 +5042,13 @@ static int mem_cgroup_slab_show(struct seq_file *m, = void *p) } #endif =20 +static ssize_t memory_min_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); +static ssize_t memory_low_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); +static ssize_t memory_high_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); + static struct cftype mem_cgroup_legacy_files[] =3D { { .name =3D "usage_in_bytes", @@ -5000,10 +5063,28 @@ static struct cftype mem_cgroup_legacy_files[] =3D { }, { .name =3D "limit_in_bytes", - .private =3D MEMFILE_PRIVATE(_MEM, RES_LIMIT), + .private =3D MEMFILE_PRIVATE(_MEM_V1, RES_LIMIT), .write =3D mem_cgroup_write, .read_u64 =3D mem_cgroup_read_u64, }, + { + .name =3D "limit_in_bytes.min", + .private =3D MEMFILE_PRIVATE(_MEM_V1, RES_LIMIT_MIN), + .write =3D memory_min_write, + .read_u64 =3D mem_cgroup_read_u64, + }, + { + .name =3D "limit_in_bytes.low", + .private =3D MEMFILE_PRIVATE(_MEM_V1, RES_LIMIT_LOW), + .write =3D memory_low_write, + .read_u64 =3D mem_cgroup_read_u64, + }, + { + .name =3D "limit_in_bytes.high", + .private =3D MEMFILE_PRIVATE(_MEM_V1, RES_LIMIT_HIGH), + .write =3D memory_high_write, + .read_u64 =3D mem_cgroup_read_u64, + }, { .name =3D "soft_limit_in_bytes", .private =3D MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), --=20 2.34.1