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 E5059C001DF for ; Fri, 4 Aug 2023 18:33:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229455AbjHDSdf (ORCPT ); Fri, 4 Aug 2023 14:33:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229700AbjHDSb4 (ORCPT ); Fri, 4 Aug 2023 14:31:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2D64559F for ; Fri, 4 Aug 2023 11:28:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id F33156210F for ; Fri, 4 Aug 2023 18:28:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56136C433C8; Fri, 4 Aug 2023 18:28:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1691173698; bh=ORwy8rEITDjnfEd/kd171ve45nMhJFNN6O7jSc6vTsk=; h=Date:To:From:Subject:From; b=xhD3yo4w/eDs8ajLwsXJJ6qEZCf0h98G2d8xavPzkxkCs0JOtMiRoXZEyU2kmQxTC fj8mOe0yJfQKEWoI0t1P4BJ8XI8yetaqkiuzuQkdFekpv6PXOq1IImRQjdu/MqTnpE c4Gkc72b28ilIo8P6UtU8gOmfCmbdMIwlNtkG7wo= Date: Fri, 04 Aug 2023 11:28:17 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, torvalds@linux-foundation.org, shuah@kernel.org, peterx@redhat.com, pbonzini@redhat.com, mgorman@techsingularity.net, mgorman@suse.de, liubo254@huawei.com, jhubbard@nvidia.com, jgg@ziepe.ca, hughd@google.com, david@redhat.com, akpm@linux-foundation.org From: Andrew Morton Subject: + selftest-mm-ksm_functional_tests-test-in-mmap_and_merge_range-if-anything-got-merged.patch added to mm-unstable branch Message-Id: <20230804182818.56136C433C8@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: selftest/mm: ksm_functional_tests: test in mmap_and_merge_range() if anything got merged has been added to the -mm mm-unstable branch. Its filename is selftest-mm-ksm_functional_tests-test-in-mmap_and_merge_range-if-anything-got-merged.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftest-mm-ksm_functional_tests-test-in-mmap_and_merge_range-if-anything-got-merged.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: David Hildenbrand Subject: selftest/mm: ksm_functional_tests: test in mmap_and_merge_range() if anything got merged Date: Thu, 3 Aug 2023 16:32:07 +0200 Let's extend mmap_and_merge_range() to test if anything in the current process was merged. range_maps_duplicates() is too unreliable for that use case, so instead look at KSM stats. Trigger a complete unmerge first, to cleanup the stable tree and stabilize accounting of merged pages. Note that we're using /proc/self/ksm_merging_pages instead of /proc/self/ksm_stat, because that one is available in more existing kernels. If /proc/self/ksm_merging_pages can't be opened, we can't perform any checks and simply skip them. We have to special-case the shared zeropage for now. But the only user -- test_unmerge_zero_pages() -- performs its own merge checks. Link: https://lkml.kernel.org/r/20230803143208.383663-7-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: John Hubbard Cc: Linus Torvalds Cc: liubo Cc: Matthew Wilcox (Oracle) Cc: Mel Gorman Cc: Mel Gorman Cc: Paolo Bonzini Cc: Peter Xu Cc: Shuah Khan Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/ksm_functional_tests.c | 47 ++++++++++++ 1 file changed, 47 insertions(+) --- a/tools/testing/selftests/mm/ksm_functional_tests.c~selftest-mm-ksm_functional_tests-test-in-mmap_and_merge_range-if-anything-got-merged +++ a/tools/testing/selftests/mm/ksm_functional_tests.c @@ -30,6 +30,7 @@ static int ksm_fd; static int ksm_full_scans_fd; static int proc_self_ksm_stat_fd; +static int proc_self_ksm_merging_pages_fd; static int ksm_use_zero_pages_fd; static int pagemap_fd; static size_t pagesize; @@ -88,6 +89,22 @@ static long get_my_ksm_zero_pages(void) return my_ksm_zero_pages; } +static long get_my_merging_pages(void) +{ + char buf[10]; + ssize_t ret; + + if (proc_self_ksm_merging_pages_fd < 0) + return proc_self_ksm_merging_pages_fd; + + ret = pread(proc_self_ksm_merging_pages_fd, buf, sizeof(buf) - 1, 0); + if (ret <= 0) + return -errno; + buf[ret] = 0; + + return strtol(buf, NULL, 10); +} + static long ksm_get_full_scans(void) { char buf[10]; @@ -120,11 +137,29 @@ static int ksm_merge(void) return 0; } +static int ksm_unmerge(void) +{ + if (write(ksm_fd, "2", 1) != 1) + return -errno; + return 0; +} + static char *mmap_and_merge_range(char val, unsigned long size, bool use_prctl) { char *map; int ret; + /* Stabilize accounting by disabling KSM completely. */ + if (ksm_unmerge()) { + ksft_test_result_fail("Disabling (unmerging) KSM failed\n"); + goto unmap; + } + + if (get_my_merging_pages() > 0) { + ksft_test_result_fail("Still pages merged\n"); + goto unmap; + } + map = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0); if (map == MAP_FAILED) { @@ -160,6 +195,16 @@ static char *mmap_and_merge_range(char v ksft_test_result_fail("Running KSM failed\n"); goto unmap; } + + /* + * Check if anything was merged at all. Ignore the zero page that is + * accounted differently (depending on kernel support). + */ + if (val && !get_my_merging_pages()) { + ksft_test_result_fail("No pages got merged\n"); + goto unmap; + } + return map; unmap: munmap(map, size); @@ -473,6 +518,8 @@ int main(int argc, char **argv) if (pagemap_fd < 0) ksft_exit_skip("open(\"/proc/self/pagemap\") failed\n"); proc_self_ksm_stat_fd = open("/proc/self/ksm_stat", O_RDONLY); + proc_self_ksm_merging_pages_fd = open("/proc/self/ksm_merging_pages", + O_RDONLY); ksm_use_zero_pages_fd = open("/sys/kernel/mm/ksm/use_zero_pages", O_RDWR); test_unmerge(); _ Patches currently in -mm which might be from david@redhat.com are mm-gup-reintroduce-foll_numa-as-foll_honor_numa_fault.patch smaps-use-vm_normal_page_pmd-instead-of-follow_trans_huge_pmd.patch mm-memory_hotplug-document-the-signal_pending-check-in-offline_pages.patch kvm-explicitly-set-foll_honor_numa_fault-in-hva_to_pfn_slow.patch mm-gup-dont-implicitly-set-foll_honor_numa_fault.patch pgtable-improve-pte_protnone-comment.patch selftest-mm-ksm_functional_tests-test-in-mmap_and_merge_range-if-anything-got-merged.patch selftest-mm-ksm_functional_tests-add-prot_none-test.patch