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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 EFE33C433DF for ; Fri, 7 Aug 2020 06:22:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C630B221E5 for ; Fri, 7 Aug 2020 06:22:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781320; bh=RuN4u55pMCP/fBpF68DHXV1C3Eb7qRzSwcB34rO+s+c=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=XicGus17D8iCLqlVbU5ZaSlgRpsOt6FfOOZRgrhQQ7UTIZG2A7b0GJ4JCR+5RzvKw q0DGGnC5v0gW+ymEfMxRQEbyTzlL9TKDekrKkM9JBwyhWIyXW79VwXVpFFzNPnoZ8l m697/upMWBaBjve4tb7L8iCESD0L+fX0GcBBkW/0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726205AbgHGGWA (ORCPT ); Fri, 7 Aug 2020 02:22:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:58344 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725893AbgHGGWA (ORCPT ); Fri, 7 Aug 2020 02:22:00 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DFE952177B; Fri, 7 Aug 2020 06:21:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781319; bh=RuN4u55pMCP/fBpF68DHXV1C3Eb7qRzSwcB34rO+s+c=; h=Date:From:To:Subject:In-Reply-To:From; b=DKYi6H1Kw9pOfNuEBDRISKKLjKD5aGAepmBrcBmle7bQGvJEmS9tQrNrSHtNW3+ae pktumNxolF8OIXH4B8xWX3JcSZrYdZVeJNmfKCzceEoYd89uYTAUa7hgMcf4pbNEyc 2lCjOV11jg62u+cHxNTduHsYVsvyJr6gfzHufLmc= Date: Thu, 06 Aug 2020 23:21:58 -0700 From: Andrew Morton To: akpm@linux-foundation.org, chris@chrisdown.name, guro@fb.com, hannes@cmpxchg.org, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, shakeelb@google.com, tj@kernel.org, torvalds@linux-foundation.org Subject: [patch 087/163] mm, memcg: unify reclaim retry limits with page allocator Message-ID: <20200807062158.KIdlvMFeD%akpm@linux-foundation.org> In-Reply-To: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Chris Down Subject: mm, memcg: unify reclaim retry limits with page allocator 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. Link: http://lkml.kernel.org/r/da557856c9c7654308eaff4eedc1952a95e8df5f.1594640214.git.chris@chrisdown.name Signed-off-by: Chris Down Reviewed-by: Shakeel Butt Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Tejun Heo Cc: Roman Gushchin Signed-off-by: Andrew Morton --- mm/memcontrol.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) --- a/mm/memcontrol.c~mm-memcg-unify-reclaim-retry-limits-with-page-allocator +++ a/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; @@ -2538,7 +2535,7 @@ 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; @@ -2615,7 +2612,7 @@ static int try_charge(struct mem_cgroup 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; @@ -2734,7 +2731,7 @@ retry: 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; @@ -3414,7 +3411,7 @@ static inline bool memcg_has_children(st */ 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(); @@ -6235,7 +6232,7 @@ static ssize_t memory_high_write(struct 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; @@ -6283,7 +6280,7 @@ static ssize_t memory_max_write(struct k 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; _