From patchwork Tue Oct 19 05:30:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shakeel Butt X-Patchwork-Id: 12568587 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24943C433EF for ; Tue, 19 Oct 2021 05:31:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9F1E46115B for ; Tue, 19 Oct 2021 05:31:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9F1E46115B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id E8A1C6B006C; Tue, 19 Oct 2021 01:31:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E3A8F900002; Tue, 19 Oct 2021 01:31:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D02406B0072; Tue, 19 Oct 2021 01:31:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0188.hostedemail.com [216.40.44.188]) by kanga.kvack.org (Postfix) with ESMTP id BD3FC6B006C for ; Tue, 19 Oct 2021 01:31:26 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 5BC29183F13BD for ; Tue, 19 Oct 2021 05:31:26 +0000 (UTC) X-FDA: 78712064172.30.533D420 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) by imf01.hostedemail.com (Postfix) with ESMTP id 42B7A5083ACE for ; Tue, 19 Oct 2021 05:31:22 +0000 (UTC) Received: by mail-pj1-f73.google.com with SMTP id a6-20020a17090aa50600b001a0a81b8664so904387pjq.6 for ; Mon, 18 Oct 2021 22:31:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=bTvjpUw+v44xOQyiDOrpyeAvjeh0PeLGrrtEgDcXk3Q=; b=dzDW55/AvVnlnOTRCBhfh/tGgo76XZN41srQjHvzCV8HWKHeQUl76UeBzWr4ow9znv GbHVRcn3t3Mu5Uq3hIC9/nWqtB6WqMbf2s0e6/VCTqvR2/AwB2CtU/n/M9w3VYZdRBhq J1upNbqXuh4/AjocATvDn3++L8iqt+SJwXxXAif5MdvOIgMRpPDA9CsuExEyiojr0tjM EWYoOt7EwwP7oHQEW+307peBxBDxlzLeb/U/9j1la6EVJLh/QxgmhbeoUK/EwHcZaYEU OW/L17k0sIQPat0B5HbggmT0XjqX+c6kEGcvSnSSvXdHM8D9Jv+iYjkF3sFSDYv81cxA 6AGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=bTvjpUw+v44xOQyiDOrpyeAvjeh0PeLGrrtEgDcXk3Q=; b=4oIg8R4tBRoRY1RCOYDHGZReH4lFzf9HFlZ6jEIShOXFy9TYP6w4csa0qiZsEmZMg6 MA19d/xJMIe1OHOQnaZ/0i7Epk6EQDylq4/VziC0/Mml4etZ/8V9hb2xmuIWBozXs5s5 zWDvP3SVgfg56771gSoW4FQwtyh+dHi6QdUIzPQ4xW4JbJ0TSrzVPhvfIoqFKS7C2Mhf wGzV8aL+KJDFo4O04hht3mzWYBH98bAzOT5NrMMCTXWlMuaVD/hNxWaWUjgfNi7EcvlK sCXShDBwXR3Q23+yVG/UjUXH+mR5JxBO3FusFjZ3gDtY8sEaNB1Q9Qiurt6CeRii2SvS xKKQ== X-Gm-Message-State: AOAM530QKFVMp/VP+ZjGbwDXnrRu2kgilZ6QhTfJpz8zJTEYU7/ZGbeD HNieiAD4E/blywj+fWcM2qfGxxcfrj2u6w== X-Google-Smtp-Source: ABdhPJzRX6EYJfwmw5Vuyhc9lAfK9sizun/NV2qiIXjkm66asup902s0JYOkrDdf6Q88RoiOVYhKWpMSzAYRig== X-Received: from shakeelb.svl.corp.google.com ([2620:15c:2cd:202:6d48:cae4:d5cb:a596]) (user=shakeelb job=sendgmr) by 2002:a17:90b:188b:: with SMTP id mn11mr4167902pjb.170.1634621484796; Mon, 18 Oct 2021 22:31:24 -0700 (PDT) Date: Mon, 18 Oct 2021 22:30:58 -0700 Message-Id: <20211019053058.2873615-1-shakeelb@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.33.0.1079.g6e70778dc9-goog Subject: [PATCH v2] memcg, kmem: further deprecate kmem.limit_in_bytes From: Shakeel Butt To: Johannes Weiner , Michal Hocko Cc: Vasily Averin , Roman Gushchin , Andrew Morton , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Shakeel Butt , Michal Hocko X-Rspamd-Queue-Id: 42B7A5083ACE Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="dzDW55/A"; spf=pass (imf01.hostedemail.com: domain of 3LFhuYQgKCKcZOHRLLSINVVNSL.JVTSPUbe-TTRcHJR.VYN@flex--shakeelb.bounces.google.com designates 209.85.216.73 as permitted sender) smtp.mailfrom=3LFhuYQgKCKcZOHRLLSINVVNSL.JVTSPUbe-TTRcHJR.VYN@flex--shakeelb.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com X-Stat-Signature: ehxigt6319fe98xipqwytout8bwghdbd X-Rspamd-Server: rspam05 X-HE-Tag: 1634621482-427189 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: The deprecation process of kmem.limit_in_bytes started with the commit 0158115f702 ("memcg, kmem: deprecate kmem.limit_in_bytes") which also explains in detail the motivation behind the deprecation. To summarize, it is the unexpected behavior on hitting the kmem limit. This patch moves the deprecation process to the next stage by disallowing to set the kmem limit. In future we might just remove the kmem.limit_in_bytes file completely. Signed-off-by: Shakeel Butt Acked-by: Roman Gushchin Acked-by: Michal Hocko Cc: Vasily Averin Cc: Johannes Weiner Cc: Andrew Morton Reviewed-by: Muchun Song --- Changes since v1: - Replaced EINVAL with ENOTSUPP on setting kmem limits. - V1 was posted last year at [0]. [0] https://lore.kernel.org/all/20201118175726.2453120-1-shakeelb@google.com/ .../admin-guide/cgroup-v1/memory.rst | 6 ++-- mm/memcontrol.c | 35 +++---------------- 2 files changed, 6 insertions(+), 35 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index 41191b5fb69d..9be961521743 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -87,10 +87,8 @@ Brief summary of control files. memory.oom_control set/show oom controls. memory.numa_stat show the number of memory usage per numa node - memory.kmem.limit_in_bytes set/show hard limit for kernel memory - This knob is deprecated and shouldn't be - used. It is planned that this be removed in - the foreseeable future. + memory.kmem.limit_in_bytes This knob is deprecated and writing to + it will return -ENOTSUPP. memory.kmem.usage_in_bytes show current kernel memory allocation memory.kmem.failcnt show the number of kernel memory usage hits limits diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8f1d9c028897..49a76049a885 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2999,7 +2999,6 @@ static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp, unsigned int nr_pages) { - struct page_counter *counter; struct mem_cgroup *memcg; int ret; @@ -3009,21 +3008,8 @@ static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp, if (ret) goto out; - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && - !page_counter_try_charge(&memcg->kmem, nr_pages, &counter)) { - - /* - * Enforce __GFP_NOFAIL allocation because callers are not - * prepared to see failures and likely do not have any failure - * handling code. - */ - if (gfp & __GFP_NOFAIL) { - page_counter_charge(&memcg->kmem, nr_pages); - goto out; - } - cancel_charge(memcg, nr_pages); - ret = -ENOMEM; - } + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + page_counter_charge(&memcg->kmem, nr_pages); out: css_put(&memcg->css); @@ -3715,17 +3701,6 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) } #endif /* CONFIG_MEMCG_KMEM */ -static int memcg_update_kmem_max(struct mem_cgroup *memcg, - unsigned long max) -{ - int ret; - - mutex_lock(&memcg_max_mutex); - ret = page_counter_set_max(&memcg->kmem, max); - mutex_unlock(&memcg_max_mutex); - return ret; -} - static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max) { int ret; @@ -3791,10 +3766,8 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of, ret = mem_cgroup_resize_max(memcg, nr_pages, true); break; case _KMEM: - pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. " - "Please report your usecase to linux-mm@kvack.org if you " - "depend on this functionality.\n"); - ret = memcg_update_kmem_max(memcg, nr_pages); + /* kmem.limit_in_bytes is deprecated. */ + ret = -ENOTSUPP; break; case _TCP: ret = memcg_update_tcp_max(memcg, nr_pages);