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=-11.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 F1C60C433E7 for ; Mon, 13 Jul 2020 11:42:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B81EE2077D for ; Mon, 13 Jul 2020 11:42:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chrisdown.name header.i=@chrisdown.name header.b="XPk/m3az" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B81EE2077D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chrisdown.name Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 56CEB8D0005; Mon, 13 Jul 2020 07:42:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 51D0F8D0001; Mon, 13 Jul 2020 07:42:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 40C6B8D0005; Mon, 13 Jul 2020 07:42:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0170.hostedemail.com [216.40.44.170]) by kanga.kvack.org (Postfix) with ESMTP id 2B3168D0001 for ; Mon, 13 Jul 2020 07:42:51 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id E39252C89 for ; Mon, 13 Jul 2020 11:42:50 +0000 (UTC) X-FDA: 77032865700.23.ants44_040f99826ee8 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id B3A6237606 for ; Mon, 13 Jul 2020 11:42:50 +0000 (UTC) X-HE-Tag: ants44_040f99826ee8 X-Filterd-Recvd-Size: 6494 Received: from mail-ed1-f68.google.com (mail-ed1-f68.google.com [209.85.208.68]) by imf20.hostedemail.com (Postfix) with ESMTP for ; Mon, 13 Jul 2020 11:42:50 +0000 (UTC) Received: by mail-ed1-f68.google.com with SMTP id h28so13334304edz.0 for ; Mon, 13 Jul 2020 04:42:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=UNFqZOOI2Y2+hjmMi9f9WyAk2VzDnQXCrSncEbD+OF8=; b=XPk/m3az111JebUG3++E4Wc34pLE+nXcrm2myLzSUtXpP/DQgp3Zg3cR1US1pAiaSG 0mGCh9yrvAoIixSWMzggOTBPUTnXB+1q7SwVYb61N8Hns40cEjd/WdPnGEmftaVWuz+Z /JdxhvRkhZqRwlwtNRjOFAMtHiRhDuGB9MNfU= 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:references :mime-version:content-disposition:in-reply-to:user-agent; bh=UNFqZOOI2Y2+hjmMi9f9WyAk2VzDnQXCrSncEbD+OF8=; b=jT9KbgUKlP6cVSKlRm0YAlwj/cQLezJZoeWE+lw9xksiCc7+mySQL475GTaEjRevEA KDK+zz4rOZ9LQXhVQNt66/7+xEoNztRkV7LnNQkqGoI720l2N0aRDoKwptBlUukRYScx 7el+bIb2aBMI+5yN8roVEj7ks8VMJzP7808Zr8F3T1D49NIfEK9eo+4M5vVHKwkWdtef CarCzrq9OUatvdccjsAeXoYSeaT4ERh3DP0CTgmlEno+G+g2gY0BcrgHDBxz5NVIZOVF zjxr/RKiF9v609pWIi27ThHJqji0xHJRlebpWAGicbByLqfHEnTVynVd/lX/8KU37+9M 7TZw== X-Gm-Message-State: AOAM533J2BQIOayBVzvhgNXi10n54/quYgKbrb/usuzCYBjcFVlLbpmW dJ8il0jypmdMG5fJXB4j/gA90w== X-Google-Smtp-Source: ABdhPJyBWP+SbDDs651fzGxZ9kryEASz/UerrssnUJ7RuqAc2LHY/8f18CH1WZPS/mJY1MOX+dZAcw== X-Received: by 2002:a05:6402:1ac4:: with SMTP id ba4mr87336086edb.60.1594640569319; Mon, 13 Jul 2020 04:42:49 -0700 (PDT) Received: from localhost ([2620:10d:c093:400::5:ef88]) by smtp.gmail.com with ESMTPSA id v24sm11220349eds.71.2020.07.13.04.42.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2020 04:42:49 -0700 (PDT) Date: Mon, 13 Jul 2020 12:42:48 +0100 From: Chris Down To: Andrew Morton Cc: Johannes Weiner , Michal Hocko , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v2 2/2] mm, memcg: unify reclaim retry limits with page allocator Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.14.5 (2020-06-23) X-Rspamd-Queue-Id: B3A6237606 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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: Reclaim retries have been set to 5 since the beginning of time in commit 66e1707bc346 ("Memory controller: add per cgroup LRU and reclaim"). However, we now have a generally agreed-upon standard for page reclaim: MAX_RECLAIM_RETRIES (currently 16), added many years later in commit 0a0337e0d1d1 ("mm, oom: rework oom detection"). In the absence of a compelling reason to declare an OOM earlier in memcg context than page allocator context, it seems reasonable to supplant MEM_CGROUP_RECLAIM_RETRIES with MAX_RECLAIM_RETRIES, making the page allocator and memcg internals more similar in semantics when reclaim fails to produce results, avoiding premature OOMs or throttling. Signed-off-by: Chris Down Cc: Andrew Morton Cc: Johannes Weiner Cc: Michal Hocko Acked-by: Michal Hocko Reviewed-by: Shakeel Butt --- mm/memcontrol.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d4b0d8af3747..672123875494 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -73,9 +73,6 @@ EXPORT_SYMBOL(memory_cgrp_subsys); struct mem_cgroup *root_mem_cgroup __read_mostly; -/* The number of times we should retry reclaim failures before giving up. */ -#define MEM_CGROUP_RECLAIM_RETRIES 5 - /* Socket memory accounting disabled? */ static bool cgroup_memory_nosocket; @@ -2540,7 +2537,7 @@ void mem_cgroup_handle_over_high(void) unsigned long pflags; unsigned long nr_reclaimed; unsigned int nr_pages = current->memcg_nr_pages_over_high; - int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + int nr_retries = MAX_RECLAIM_RETRIES; struct mem_cgroup *memcg; bool in_retry = false; @@ -2617,7 +2614,7 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, unsigned int nr_pages) { unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages); - int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + int nr_retries = MAX_RECLAIM_RETRIES; struct mem_cgroup *mem_over_limit; struct page_counter *counter; unsigned long nr_reclaimed; @@ -2736,7 +2733,7 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, get_order(nr_pages * PAGE_SIZE)); switch (oom_status) { case OOM_SUCCESS: - nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + nr_retries = MAX_RECLAIM_RETRIES; goto retry; case OOM_FAILED: goto force; @@ -3396,7 +3393,7 @@ static inline bool memcg_has_children(struct mem_cgroup *memcg) */ static int mem_cgroup_force_empty(struct mem_cgroup *memcg) { - int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + int nr_retries = MAX_RECLAIM_RETRIES; /* we call try-to-free pages for make this cgroup empty */ lru_add_drain_all(); @@ -6225,7 +6222,7 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - unsigned int nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + unsigned int nr_retries = MAX_RECLAIM_RETRIES; bool drained = false; unsigned long high; int err; @@ -6273,7 +6270,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - unsigned int nr_reclaims = MEM_CGROUP_RECLAIM_RETRIES; + unsigned int nr_reclaims = MAX_RECLAIM_RETRIES; bool drained = false; unsigned long max; int err; -- 2.27.0