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=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 6795AC4321A for ; Fri, 28 Jun 2019 11:16:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E142208E3 for ; Fri, 28 Jun 2019 11:16:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="CLpGl7MV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbfF1LQc (ORCPT ); Fri, 28 Jun 2019 07:16:32 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:44787 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726502AbfF1LQb (ORCPT ); Fri, 28 Jun 2019 07:16:31 -0400 Received: by mail-pl1-f194.google.com with SMTP id t7so3064050plr.11 for ; Fri, 28 Jun 2019 04:16:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :in-reply-to:user-agent; bh=9sipjHExFeuV0K4UVRepUa+lADx+MbUcc8ZZsr0g1z8=; b=CLpGl7MVAA5z/efotkyK3c2z4dD4AyInMNHT0tUmc4cqfeE8y9vwvj39u7b2zrD+et tCIRt/5GhFSMwXDep80CHeU3SqpJ28HmcmX/uBjE/EUvGWpWdB574k6n2+lJjixspJXt +YP6iNPdTakoR7dOl9eV/8GCUDGT7GwROXAus= 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:mime-version :content-disposition:in-reply-to:user-agent; bh=9sipjHExFeuV0K4UVRepUa+lADx+MbUcc8ZZsr0g1z8=; b=lMj9g2EpVFcpIBM72CMHovi+PbeolPjpVxrK5Lx2kdo2r9W9G5OBPI+QL3LJdy0rZD zDG/ZMZXj9VX7AS2BSgUp25zSCVObjUIsQEXhXXzbaxgpLzfMvImtafY1/T1ybp+0SnO Umi/LdHPGpc0a0LvjBNCeb7xa2BATPtR09D0zrQE8D93baC7kRgjU5TeOEI/Tb0ElUMi LOK1ZjZM28XqD20GrO9yVgTQCI9dLSPYvyUYoqscDyO+Fi5+Hs3IrD2kv7jfs6pfypib zcyxO8okhUOoi5hFOZoejuQJudldL/e3na0Ob6PFDZQc3e4XLKu6I4KlmDLmj8rbo+Wj d+Mw== X-Gm-Message-State: APjAAAVTglGQhoRbnSVQsDJe20+0s8+HyRYWCAbtqQtH/98RHQSDAYT3 7/z8XVhreP/vyF0r08EfFtDn0VC3xvtQ X-Google-Smtp-Source: APXvYqwFBxOXRwJS5o/s0J9UhYNxGdQOVXQ/vWFl+RQQGuFDJp2kNVy5jlupPWRbnXu8ylFSsIEXdQ== X-Received: by 2002:a17:902:b20c:: with SMTP id t12mr11043488plr.285.1561720590639; Fri, 28 Jun 2019 04:16:30 -0700 (PDT) Received: from google.com ([2401:fa00:1:b:d89e:cfa6:3c8:e61b]) by smtp.gmail.com with ESMTPSA id n184sm1893411pfn.21.2019.06.28.04.16.28 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 28 Jun 2019 04:16:30 -0700 (PDT) Date: Fri, 28 Jun 2019 19:16:27 +0800 From: Kuo-Hsin Yang To: Andrew Morton , Johannes Weiner Cc: Minchan Kim , Michal Hocko , Sonny Rao , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2] mm: vmscan: fix not scanning anonymous pages when detecting file refaults Message-ID: <20190628111627.GA107040@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190619080835.GA68312@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When file refaults are detected and there are many inactive file pages, the system never reclaim anonymous pages, the file pages are dropped aggressively when there are still a lot of cold anonymous pages and system thrashes. This issue impacts the performance of applications with large executable, e.g. chrome. Commit 2a2e48854d70 ("mm: vmscan: fix IO/refault regression in cache workingset transition") introduced actual_reclaim parameter. When file refaults are detected, inactive_list_is_low() may return different values depends on the actual_reclaim parameter. Vmscan would only scan active/inactive file lists at file thrashing state when the following 2 conditions are satisfied. 1) inactive_list_is_low() returns false in get_scan_count() to trigger scanning file lists only. 2) inactive_list_is_low() returns true in shrink_list() to allow scanning active file list. This patch makes the return value of inactive_list_is_low() independent of actual_reclaim and rename the parameter back to trace. The problem can be reproduced by the following test program. ---8<--- void fallocate_file(const char *filename, off_t size) { struct stat st; int fd; if (!stat(filename, &st) && st.st_size >= size) return; fd = open(filename, O_WRONLY | O_CREAT, 0600); if (fd < 0) { perror("create file"); exit(1); } if (posix_fallocate(fd, 0, size)) { perror("fallocate"); exit(1); } close(fd); } long *alloc_anon(long size) { long *start = malloc(size); memset(start, 1, size); return start; } long access_file(const char *filename, long size, long rounds) { int fd, i; volatile char *start1, *end1, *start2; const int page_size = getpagesize(); long sum = 0; fd = open(filename, O_RDONLY); if (fd == -1) { perror("open"); exit(1); } /* * Some applications, e.g. chrome, use a lot of executable file * pages, map some of the pages with PROT_EXEC flag to simulate * the behavior. */ start1 = mmap(NULL, size / 2, PROT_READ | PROT_EXEC, MAP_SHARED, fd, 0); if (start1 == MAP_FAILED) { perror("mmap"); exit(1); } end1 = start1 + size / 2; start2 = mmap(NULL, size / 2, PROT_READ, MAP_SHARED, fd, size / 2); if (start2 == MAP_FAILED) { perror("mmap"); exit(1); } for (i = 0; i < rounds; ++i) { struct timeval before, after; volatile char *ptr1 = start1, *ptr2 = start2; gettimeofday(&before, NULL); for (; ptr1 < end1; ptr1 += page_size, ptr2 += page_size) sum += *ptr1 + *ptr2; gettimeofday(&after, NULL); printf("File access time, round %d: %f (sec)\n", i, (after.tv_sec - before.tv_sec) + (after.tv_usec - before.tv_usec) / 1000000.0); } return sum; } int main(int argc, char *argv[]) { const long MB = 1024 * 1024; long anon_mb, file_mb, file_rounds; const char filename[] = "large"; long *ret1; long ret2; if (argc != 4) { printf("usage: thrash ANON_MB FILE_MB FILE_ROUNDS\n"); exit(0); } anon_mb = atoi(argv[1]); file_mb = atoi(argv[2]); file_rounds = atoi(argv[3]); fallocate_file(filename, file_mb * MB); printf("Allocate %ld MB anonymous pages\n", anon_mb); ret1 = alloc_anon(anon_mb * MB); printf("Access %ld MB file pages\n", file_mb); ret2 = access_file(filename, file_mb * MB, file_rounds); printf("Print result to prevent optimization: %ld\n", *ret1 + ret2); return 0; } ---8<--- Running the test program on 2GB RAM VM with kernel 5.2.0-rc5, the program fills ram with 2048 MB memory, access a 200 MB file for 10 times. Without this patch, the file cache is dropped aggresively and every access to the file is from disk. $ ./thrash 2048 200 10 Allocate 2048 MB anonymous pages Access 200 MB file pages File access time, round 0: 2.489316 (sec) File access time, round 1: 2.581277 (sec) File access time, round 2: 2.487624 (sec) File access time, round 3: 2.449100 (sec) File access time, round 4: 2.420423 (sec) File access time, round 5: 2.343411 (sec) File access time, round 6: 2.454833 (sec) File access time, round 7: 2.483398 (sec) File access time, round 8: 2.572701 (sec) File access time, round 9: 2.493014 (sec) With this patch, these file pages can be cached. $ ./thrash 2048 200 10 Allocate 2048 MB anonymous pages Access 200 MB file pages File access time, round 0: 2.475189 (sec) File access time, round 1: 2.440777 (sec) File access time, round 2: 2.411671 (sec) File access time, round 3: 1.955267 (sec) File access time, round 4: 0.029924 (sec) File access time, round 5: 0.000808 (sec) File access time, round 6: 0.000771 (sec) File access time, round 7: 0.000746 (sec) File access time, round 8: 0.000738 (sec) File access time, round 9: 0.000747 (sec) Fixes: 2a2e48854d70 ("mm: vmscan: fix IO/refault regression in cache workingset transition") Signed-off-by: Kuo-Hsin Yang Acked-by: Johannes Weiner --- mm/vmscan.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 7889f583ced9f..da0b97204372e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2125,7 +2125,7 @@ static void shrink_active_list(unsigned long nr_to_scan, * 10TB 320 32GB */ static bool inactive_list_is_low(struct lruvec *lruvec, bool file, - struct scan_control *sc, bool actual_reclaim) + struct scan_control *sc, bool trace) { enum lru_list active_lru = file * LRU_FILE + LRU_ACTIVE; struct pglist_data *pgdat = lruvec_pgdat(lruvec); @@ -2151,7 +2151,7 @@ static bool inactive_list_is_low(struct lruvec *lruvec, bool file, * rid of the stale workingset quickly. */ refaults = lruvec_page_state_local(lruvec, WORKINGSET_ACTIVATE); - if (file && actual_reclaim && lruvec->refaults != refaults) { + if (file && lruvec->refaults != refaults) { inactive_ratio = 0; } else { gb = (inactive + active) >> (30 - PAGE_SHIFT); @@ -2161,7 +2161,7 @@ static bool inactive_list_is_low(struct lruvec *lruvec, bool file, inactive_ratio = 1; } - if (actual_reclaim) + if (trace) trace_mm_vmscan_inactive_list_is_low(pgdat->node_id, sc->reclaim_idx, lruvec_lru_size(lruvec, inactive_lru, MAX_NR_ZONES), inactive, lruvec_lru_size(lruvec, active_lru, MAX_NR_ZONES), active, -- 2.22.0.410.gd8fdbe21b5-goog