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 BB918C433F5 for ; Mon, 27 Dec 2021 15:37:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238868AbhL0Phq (ORCPT ); Mon, 27 Dec 2021 10:37:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238579AbhL0PgO (ORCPT ); Mon, 27 Dec 2021 10:36:14 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B88DC061B38; Mon, 27 Dec 2021 07:35:50 -0800 (PST) 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 sin.source.kernel.org (Postfix) with ESMTPS id 9D5E4CE10D9; Mon, 27 Dec 2021 15:35:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65E1CC36AEB; Mon, 27 Dec 2021 15:35:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640619346; bh=L3jzjkZJuoA19T9M7XeHKugIqeJMbTHiY4W+mhtIqfo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nLJ/qNzQPPFbJj3Sr6/O9O2RGgJ9d0KECYSzmQ5QCPa9DwWGM1+4Ar3Nu7AQhT13x sudom1Es/UUHSRRqyTPJ6vP36UImVjtDKh1q02YZiXwEldhk4VMy1qQRyNZLqVCmAC /hljAt7nUalaAQs6lLyBLdx6HC3kcMDp2jOAqk9U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrey Ryabinin , Michal Hocko , Mel Gorman , David Rientjes , Andrea Arcangeli , Andrew Morton , Linus Torvalds Subject: [PATCH 5.4 39/47] mm: mempolicy: fix THP allocations escaping mempolicy restrictions Date: Mon, 27 Dec 2021 16:31:15 +0100 Message-Id: <20211227151322.146610498@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211227151320.801714429@linuxfoundation.org> References: <20211227151320.801714429@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrey Ryabinin commit 338635340669d5b317c7e8dcf4fff4a0f3651d87 upstream. 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 Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/mempolicy.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2143,8 +2143,9 @@ alloc_pages_vma(gfp_t gfp, int order, st * memory as well. */ if (!page && (gfp & __GFP_DIRECT_RECLAIM)) - page = __alloc_pages_node(hpage_node, - gfp | __GFP_NORETRY, order); + page = __alloc_pages_nodemask(gfp | __GFP_NORETRY, + order, hpage_node, + nmask); goto out; }