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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFE2BC433F5 for ; Sat, 25 Dec 2021 05:12:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229795AbhLYFMj (ORCPT ); Sat, 25 Dec 2021 00:12:39 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:49778 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229463AbhLYFMj (ORCPT ); Sat, 25 Dec 2021 00:12:39 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 00743B80AEA; Sat, 25 Dec 2021 05:12:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 627B7C36AE5; Sat, 25 Dec 2021 05:12:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1640409156; bh=uNyKebTzcIdoglhu867uyKUwwjmt/U1M4h+OErPnlAs=; h=Date:From:To:Subject:In-Reply-To:From; b=z4spDwkGBXW72yMFNbBX5Rad5oFe+mgXRuhMnaY/X3gioxuD37YNttVgc6opgB/yf m4tgra8mjYTWXbFBJ1lwhDO+Bo5dlzIIyXDYUp6tYLcGeIxoG9jmyttquldDkBy2KB 82L/avVMYi4MQMmfBI0h+qslNE2i/JvCQZiVlq88= Date: Fri, 24 Dec 2021 21:12:35 -0800 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, arbn@yandex-team.com, linux-mm@kvack.org, mgorman@techsingularity.net, mhocko@suse.com, mm-commits@vger.kernel.org, rientjes@google.com, stable@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 2/9] mm: mempolicy: fix THP allocations escaping mempolicy restrictions Message-ID: <20211225051235.JoA_I5IqL%akpm@linux-foundation.org> In-Reply-To: <20211224211127.30b60764d059ff3b0afea38a@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Andrey Ryabinin Subject: mm: mempolicy: fix THP allocations escaping mempolicy restrictions alloc_pages_vma() may try to allocate THP page on the local NUMA node first: page = __alloc_pages_node(hpage_node, gfp | __GFP_THISNODE | __GFP_NORETRY, order); And if the allocation fails it retries allowing remote memory: if (!page && (gfp & __GFP_DIRECT_RECLAIM)) page = __alloc_pages_node(hpage_node, gfp, order); However, this retry allocation completely ignores memory policy nodemask allowing allocation to escape restrictions. The first appearance of this bug seems to be the commit ac5b2c18911f ("mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings") The bug disappeared later in the commit 89c83fb539f9 ("mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask") and reappeared again in slightly different form in the commit 76e654cc91bb ("mm, page_alloc: allow hugepage fallback to remote nodes when madvised") Fix this by passing correct nodemask to the __alloc_pages() call. The demonstration/reproducer of the problem: $ mount -oremount,size=4G,huge=always /dev/shm/ $ echo always > /sys/kernel/mm/transparent_hugepage/defrag $ cat mbind_thp.c #include #include #include #include #include #include #include #include #define SIZE 2ULL << 30 int main(int argc, char **argv) { int fd; unsigned long long i; char *addr; pid_t pid; char buf[100]; unsigned long nodemask = 1; fd = open("/dev/shm/test", O_RDWR|O_CREAT); assert(fd > 0); assert(ftruncate(fd, SIZE) == 0); addr = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); assert(mbind(addr, SIZE, MPOL_BIND, &nodemask, 2, MPOL_MF_STRICT|MPOL_MF_MOVE)==0); for (i = 0; i < SIZE; i+=4096) { addr[i] = 1; } pid = getpid(); snprintf(buf, sizeof(buf), "grep shm /proc/%d/numa_maps", pid); system(buf); sleep(10000); return 0; } $ gcc mbind_thp.c -o mbind_thp -lnuma $ numactl -H available: 2 nodes (0-1) node 0 cpus: 0 2 node 0 size: 1918 MB node 0 free: 1595 MB node 1 cpus: 1 3 node 1 size: 2014 MB node 1 free: 1731 MB node distances: node 0 1 0: 10 20 1: 20 10 $ rm -f /dev/shm/test; taskset -c 0 ./mbind_thp 7fd970a00000 bind:0 file=/dev/shm/test dirty=524288 active=0 N0=396800 N1=127488 kernelpagesize_kB=4 Link: https://lkml.kernel.org/r/20211208165343.22349-1-arbn@yandex-team.com Fixes: ac5b2c18911f ("mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings") Signed-off-by: Andrey Ryabinin Acked-by: Michal Hocko Acked-by: Mel Gorman Acked-by: David Rientjes Cc: Andrea Arcangeli Cc: Signed-off-by: Andrew Morton --- mm/mempolicy.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/mm/mempolicy.c~mm-mempolicy-fix-thp-allocations-escaping-mempolicy-restrictions +++ a/mm/mempolicy.c @@ -2140,8 +2140,7 @@ struct page *alloc_pages_vma(gfp_t gfp, * memory with both reclaim and compact as well. */ if (!page && (gfp & __GFP_DIRECT_RECLAIM)) - page = __alloc_pages_node(hpage_node, - gfp, order); + page = __alloc_pages(gfp, order, hpage_node, nmask); goto out; } _