From patchwork Thu Jun 2 14:56:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Jakub_Mat=C4=9Bna?= X-Patchwork-Id: 12867952 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A036ACCA478 for ; Thu, 2 Jun 2022 14:56:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C06246B0074; Thu, 2 Jun 2022 10:56:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BB54A6B0075; Thu, 2 Jun 2022 10:56:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 990966B007B; Thu, 2 Jun 2022 10:56:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 65F826B0075 for ; Thu, 2 Jun 2022 10:56:29 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 34DE535800 for ; Thu, 2 Jun 2022 14:56:29 +0000 (UTC) X-FDA: 79533596898.16.1142F27 Received: from mail-ej1-f53.google.com (mail-ej1-f53.google.com [209.85.218.53]) by imf08.hostedemail.com (Postfix) with ESMTP id 93BAB160066 for ; Thu, 2 Jun 2022 14:56:02 +0000 (UTC) Received: by mail-ej1-f53.google.com with SMTP id rq11so10502928ejc.4 for ; Thu, 02 Jun 2022 07:56:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=plkRHxZRk9CMIn7YOznv+vuUGRy66YRIHBjRF967Ovg=; b=HftDeftCoaRwOnKYKg0+jnbxtHNvBbjODuhXYFO2QbjQW5f2p1vZ7QR7lSPhi1Tpo6 zQIf0SsRnaoMYlNDJFjxwnMh0QxywoReN/NUiqPmEw9khk+s1id55epnrkyctNSlBng6 yZgze0/sBJmFciSLBnov0zru92Wm/r0oJ/bJQETbLT9tapPwyTQklrP8gqMqqvP6OWGS AUb1idz8HGGjiiKLtrWKIUKRczniTp5YLo1dlGC7Zlj0qRCzdWwvRhOIqYYXPuIxSM13 SoaHQWmF9A4AIz75alU5K+N87Ip4goG9RRLb7djoRNAixjUaLSzb+gafziTdUn3BhBUu J7ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=plkRHxZRk9CMIn7YOznv+vuUGRy66YRIHBjRF967Ovg=; b=SnR5ywAPiBV9HOh5C3e4WzfHPk5mKcpM1yVz0fVvMAdfhP6PDQ8+eZZUzJCePUyeV3 NV1NrnF31RKM55fKmn2j8W7nNC3MWv9NlemisV5UljOjIhpNVGJgb2Gh+qRYUFRWD5Ah 4RaxI3/iiYK6bdObb/tMdnohN6iq9KlWXhLP1vsgKOIAxjsW7/fpaMqWa8GqaMLr4ugK TXHjHpeIfuhqLFFmYPBs0bLrwXwEgTJ8k5SaZJvXSOZC9WrKaVOdJaj4Fcgv03aE++6V 2xI3yMPD7PiJkwaEOFJu3SBa8YFQ6+2h29RL+zl5iGD3gaxcgOtStp8SZRIRpBvVLnTi Utqg== X-Gm-Message-State: AOAM5336KjEJlZfTRXOnZ83vW3xxLf3HcK3cWkwwnwvPyCzCmSrhzhda 8t8SIAy9TEVcGsrN7Ylz9rk= X-Google-Smtp-Source: ABdhPJydHQyQWjXz9p+kXVNMSBYSkBhpBXvIgTo6+N7WpZ4t+zvxXoay5Q2cKcCAKpn4Duv4qsQt0A== X-Received: by 2002:a17:907:728a:b0:6fe:f10b:80cc with SMTP id dt10-20020a170907728a00b006fef10b80ccmr4452079ejc.22.1654181784494; Thu, 02 Jun 2022 07:56:24 -0700 (PDT) Received: from orion.localdomain ([93.99.228.15]) by smtp.gmail.com with ESMTPSA id h15-20020a170906590f00b007081c5ce04dsm1589173ejq.58.2022.06.02.07.56.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Jun 2022 07:56:23 -0700 (PDT) Received: by orion.localdomain (Postfix, from userid 1003) id 2E073A0887; Thu, 2 Jun 2022 16:56:57 +0200 (CEST) From: =?utf-8?q?Jakub_Mat=C4=9Bna?= To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org, vbabka@suse.cz, mhocko@kernel.org, mgorman@techsingularity.net, willy@infradead.org, liam.howlett@oracle.com, hughd@google.com, kirill@shutemov.name, riel@surriel.com, rostedt@goodmis.org, peterz@infradead.org, =?utf-8?q?Jakub_Mat=C4=9Bna?= Subject: [PATCH 2/2] [PATCH 2/2] mm: add merging after mremap resize Date: Thu, 2 Jun 2022 16:56:42 +0200 Message-Id: <20220602145642.16948-3-matenajakub@gmail.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220602145642.16948-1-matenajakub@gmail.com> References: <20220602145642.16948-1-matenajakub@gmail.com> MIME-Version: 1.0 X-Stat-Signature: af7ehc6s5tyqq6dkw87px6wc1e4q8yw6 Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=HftDeftC; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf08.hostedemail.com: domain of matenajakub@gmail.com designates 209.85.218.53 as permitted sender) smtp.mailfrom=matenajakub@gmail.com X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 93BAB160066 X-HE-Tag: 1654181762-302667 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: When mremap call results in expansion, it might be possible to merge the VMA with the next VMA which might become adjacent. This patch adds vma_merge call after the expansion is done to try and merge. Signed-off-by: Jakub Matěna --- mm/mremap.c | 19 +++++++++- tools/testing/selftests/vm/mremap_test.c | 47 +++++++++++++++++++++++- 2 files changed, 63 insertions(+), 3 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index 0b93fac76851..66970dcd636a 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -9,6 +9,7 @@ */ #include +#include #include #include #include @@ -23,6 +24,7 @@ #include #include #include +#include #include #include @@ -1014,6 +1016,9 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, /* can we just expand the current mapping? */ if (vma_expandable(vma, new_len - old_len)) { long pages = (new_len - old_len) >> PAGE_SHIFT; + unsigned long extension_start = addr + old_len; + unsigned long extension_end = addr + new_len; + pgoff_t extension_pgoff = vma->vm_pgoff + (old_len >> PAGE_SHIFT); if (vma->vm_flags & VM_ACCOUNT) { if (security_vm_enough_memory_mm(mm, pages)) { @@ -1022,8 +1027,18 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, } } - if (vma_adjust(vma, vma->vm_start, addr + new_len, - vma->vm_pgoff, NULL)) { + /* + * Function vma_merge() is called on the extension we are adding to + * the already existing vma, vma_merge() will merge this extension with + * the already existing vma (expand operation itself) and possibly also + * with the next vma if it becomes adjacent to the expanded vma and + * otherwise compatible. + */ + vma = vma_merge(mm, vma, extension_start, extension_end, + vma->vm_flags, vma->anon_vma, vma->vm_file, + extension_pgoff, vma_policy(vma), + vma->vm_userfaultfd_ctx, anon_vma_name(vma)); + if (!vma) { vm_unacct_memory(pages); ret = -ENOMEM; goto out; diff --git a/tools/testing/selftests/vm/mremap_test.c b/tools/testing/selftests/vm/mremap_test.c index db0270127aeb..0865a6cb5bdb 100644 --- a/tools/testing/selftests/vm/mremap_test.c +++ b/tools/testing/selftests/vm/mremap_test.c @@ -118,6 +118,48 @@ static unsigned long long get_mmap_min_addr(void) return addr; } +/* + * This test validates that merge is called when expanding a mapping. + * Mapping containing three pages is created, middle page is unmapped + * and then the mapping containing the first page is expanded so that + * it fills the created hole. The two parts should merge creating + * single mapping with three pages. + */ +static void mremap_expand_merge(unsigned long page_size) +{ + char *test_name = "mremap expand merge"; + FILE *fp; + char *line = NULL; + size_t len = 0; + bool success = false; + + char *start = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + munmap(start + page_size, page_size); + mremap(start, page_size, 2 * page_size, 0); + + fp = fopen("/proc/self/maps", "r"); + if (fp == NULL) { + ksft_test_result_fail("%s\n", test_name); + return; + } + + while(getline(&line, &len, fp) != -1) { + char *first = strtok(line,"- "); + void *first_val = (void *) strtol(first, NULL, 16); + char *second = strtok(NULL,"- "); + void *second_val = (void *) strtol(second, NULL, 16); + if (first_val == start && second_val == start + 3 * page_size) { + success = true; + break; + } + } + if (success) + ksft_test_result_pass("%s\n", test_name); + else + ksft_test_result_fail("%s\n", test_name); + fclose(fp); +} + /* * Returns the start address of the mapping on success, else returns * NULL on failure. @@ -336,6 +378,7 @@ int main(int argc, char **argv) int i, run_perf_tests; unsigned int threshold_mb = VALIDATION_DEFAULT_THRESHOLD; unsigned int pattern_seed; + int num_expand_tests = 1; struct test test_cases[MAX_TEST]; struct test perf_test_cases[MAX_PERF_TEST]; int page_size; @@ -407,12 +450,14 @@ int main(int argc, char **argv) (threshold_mb * _1MB >= _1GB); ksft_set_plan(ARRAY_SIZE(test_cases) + (run_perf_tests ? - ARRAY_SIZE(perf_test_cases) : 0)); + ARRAY_SIZE(perf_test_cases) : 0) + num_expand_tests); for (i = 0; i < ARRAY_SIZE(test_cases); i++) run_mremap_test_case(test_cases[i], &failures, threshold_mb, pattern_seed); + mremap_expand_merge(page_size); + if (run_perf_tests) { ksft_print_msg("\n%s\n", "mremap HAVE_MOVE_PMD/PUD optimization time comparison for 1GB region:");