From nobody Wed Feb 11 08:11:32 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 8EDB3C761A6 for ; Tue, 4 Apr 2023 20:50:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236346AbjDDUua (ORCPT ); Tue, 4 Apr 2023 16:50:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236350AbjDDUuZ (ORCPT ); Tue, 4 Apr 2023 16:50:25 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F2434C25; Tue, 4 Apr 2023 13:50:24 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id ix20so32518178plb.3; Tue, 04 Apr 2023 13:50:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680641423; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=lglI8SHFdENU7LxVGQcu2UFVz8VugpbHJeSn7gO+RPc=; b=Nrw6i/FJkS+fqTHL9se7KaV8CBQ8xPVRt4LMvU2Do9i/mTfZSgWVYiqA/pz4ECapQQ tCpnUOnnfw0CQgEFR/FRbB9ejV68iU6P0vReR7IiHWMWh7XWRvd/zt3D7oPfgKzu8ZVL PFBGzhqG/eQ1Wg6dC/pz5EitUrx3E0FtWzBZHDob4owJKiqepla9rrMevQICz2jTD6sB IxCbiS3TOw5KrDKlwAMI7w2UXHiOSgdPeq6lxmP+5+46AFNq0b6/co31Vf/ozknj+8zJ x1LZzrI54HRvbU9F97DUHeoGyEX15x6ETRsdEZyk/TEk+xCTpDfq4O7jGHmFkSr5In1k FRow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680641423; 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=lglI8SHFdENU7LxVGQcu2UFVz8VugpbHJeSn7gO+RPc=; b=ZzNcOg0l55KuBHStiSkxAWJ5pitgMY5BT93oTM+8qbvsE+5Jc19EYhxJKVf/tpE5K3 MCd0eENVb+7Oy0nEIvA/eCv64eFSX+mGWnxloyv5KyYkVmpKosJbMSe24Sy2rsN535BP kDZLMNdpwYt8ZyMwzm3lfyKl0rMuk7X/f6lYWAFqlMfuFfXJfdX9Guj+bkcM0nwBFF1Q 2MyltgG6dP31ecckpRnsJhQ8rWcqMAFzpT+2P+UtL6l4RaC+fT8QrG+EE7XnQYuzIXtS 2gDGl1p8AnrrkhBy1lfGecHv3t1cYO13kViszZDUTor+RAojRgTogdUaiD70bYH/5yHP wQ1Q== X-Gm-Message-State: AAQBX9fDT5VNtuY/jYyru6aDkygI1T862rmUgJ881QWMzhIOEwtkc9N9 GOd2u6SdGGwXXbYeofxXREqldmcFpqCO+QUL X-Google-Smtp-Source: AKy350YCVMZqXw6ZiGurBjzNmoYBsAbAsOz/1gvcWpAAID0BsOihl1waiyFK0dykig976XfgWdUntw== X-Received: by 2002:a17:903:244f:b0:1a1:ce5d:5a15 with SMTP id l15-20020a170903244f00b001a1ce5d5a15mr4998933pls.50.1680641423186; Tue, 04 Apr 2023 13:50:23 -0700 (PDT) Received: from lunar.aeonazure.com ([182.2.143.216]) by smtp.gmail.com with ESMTPSA id d9-20020a170902728900b0019f2328bef8sm8818551pll.34.2023.04.04.13.50.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Apr 2023 13:50:22 -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 03:50:13 +0700 Message-Id: <20230404205013.31520-1-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 --- mm/memcontrol.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 83 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5abffe6f8389..eec6e6ed92f8 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 @@ -208,6 +220,7 @@ enum res_type { _MEMSWAP, _KMEM, _TCP, + _MEM_V1, }; =20 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) @@ -3689,6 +3702,9 @@ 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, @@ -3699,6 +3715,7 @@ 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: @@ -3729,6 +3746,12 @@ 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(); } @@ -3828,6 +3851,35 @@ 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, + u64 nr_pages) +{ + u64 max =3D (u64)(PAGE_COUNTER_MAX * PAGE_SIZE) / PAGE_SIZE; + u64 min, low, high; + + if (mem_cgroup_is_root(memcg) || 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. @@ -3851,6 +3903,11 @@ 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; @@ -4999,6 +5056,13 @@ 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", @@ -5013,10 +5077,28 @@ 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