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=-11.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 DEE46C388F9 for ; Thu, 22 Oct 2020 14:52:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0F7B924630 for ; Thu, 22 Oct 2020 14:52:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F7B924630 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7E4206B0071; Thu, 22 Oct 2020 10:52:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7960D6B0073; Thu, 22 Oct 2020 10:52:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6D1C56B0074; Thu, 22 Oct 2020 10:52:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0189.hostedemail.com [216.40.44.189]) by kanga.kvack.org (Postfix) with ESMTP id 3EE9F6B0071 for ; Thu, 22 Oct 2020 10:52:45 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id C19F78A74370 for ; Thu, 22 Oct 2020 14:52:44 +0000 (UTC) X-FDA: 77399853048.11.toes14_090e9ac27251 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin11.hostedemail.com (Postfix) with ESMTP id 5CD25180F8B81 for ; Thu, 22 Oct 2020 14:52:44 +0000 (UTC) X-HE-Tag: toes14_090e9ac27251 X-Filterd-Recvd-Size: 4460 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf43.hostedemail.com (Postfix) with ESMTP for ; Thu, 22 Oct 2020 14:52:43 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id AD285AC6D; Thu, 22 Oct 2020 14:52:42 +0000 (UTC) Subject: Re: [PATCH] mm,thp,shmem: limit shmem THP alloc gfp_mask From: Vlastimil Babka To: Rik van Riel , Hugh Dickins , Xu Yu Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Mel Gorman , Andrea Arcangeli , Matthew Wilcox , Michal Hocko References: <20201021234846.5cc97e62@imladris.surriel.com> <06c1e573-cddd-c17c-9f18-3af2d9d09f80@suse.cz> Message-ID: <2b7f401d-8041-9d64-595d-f95109a52e3b@suse.cz> Date: Thu, 22 Oct 2020 16:52:42 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.2 MIME-Version: 1.0 In-Reply-To: <06c1e573-cddd-c17c-9f18-3af2d9d09f80@suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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: On 10/22/20 4:51 PM, Vlastimil Babka wrote: > On 10/22/20 5:48 AM, Rik van Riel wrote: >> The allocation flags of anonymous transparent huge pages can be controlled >> through the files in /sys/kernel/mm/transparent_hugepage/defrag, which can >> help the system from getting bogged down in the page reclaim and compaction >> code when many THPs are getting allocated simultaneously. >> >> However, the gfp_mask for shmem THP allocations were not limited by those >> configuration settings, and some workloads ended up with all CPUs stuck >> on the LRU lock in the page reclaim code, trying to allocate dozens of >> THPs simultaneously. >> >> This patch applies the same configurated limitation of THPs to shmem >> hugepage allocations, to prevent that from happening. >> >> This way a THP defrag setting of "never" or "defer+madvise" will result >> in quick allocation failures without direct reclaim when no 2MB free >> pages are available. >> >> Signed-off-by: Rik van Riel > > FTR, a patch to the same effect was sent by Xu Yu: Hm thought I did CC, but TB ate it. sorry for the noise > https://lore.kernel.org/r/11e1ead211eb7d141efa0eb75a46ee2096ee63f8.1603267572.git.xuyu@linux.alibaba.com > >> --- >> >> diff --git a/include/linux/gfp.h b/include/linux/gfp.h >> index c603237e006c..0a5b164a26d9 100644 >> --- a/include/linux/gfp.h >> +++ b/include/linux/gfp.h >> @@ -614,6 +614,8 @@ bool gfp_pfmemalloc_allowed(gfp_t gfp_mask); >> extern void pm_restrict_gfp_mask(void); >> extern void pm_restore_gfp_mask(void); >> >> +extern gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma); >> + >> #ifdef CONFIG_PM_SLEEP >> extern bool pm_suspended_storage(void); >> #else >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index 9474dbc150ed..9b08ce5cc387 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -649,7 +649,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, >> * available >> * never: never stall for any thp allocation >> */ >> -static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma) >> +gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma) >> { >> const bool vma_madvised = !!(vma->vm_flags & VM_HUGEPAGE); >> >> diff --git a/mm/shmem.c b/mm/shmem.c >> index 537c137698f8..d1290eb508e5 100644 >> --- a/mm/shmem.c >> +++ b/mm/shmem.c >> @@ -1545,8 +1545,11 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp, >> return NULL; >> >> shmem_pseudo_vma_init(&pvma, info, hindex); >> - page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN, >> - HPAGE_PMD_ORDER, &pvma, 0, numa_node_id(), true); >> + /* Limit the gfp mask according to THP configuration. */ >> + gfp |= __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN; >> + gfp &= alloc_hugepage_direct_gfpmask(&pvma); >> + page = alloc_pages_vma(gfp, HPAGE_PMD_ORDER, &pvma, 0, numa_node_id(), >> + true); >> shmem_pseudo_vma_destroy(&pvma); >> if (page) >> prep_transhuge_page(page); >> >