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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Kevin Brodsky Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Yeoreum Yun X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2707; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=pUsAF+NKDxZAuOCu2xwNuQnOqeW4ovfuiE8VNrQZxHY=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqmBIG+FE6+7XlWbhEWVG74JauIQOW9hAlYcR6g GGYuvk9XL+JAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCapgSBgAKCRBt1cPRWsUx MxCKDACXbSM/L+bTkLJMqPzk1LV+saJ5txv8ckKPghKNpOFx2JvGS6r1L2WaA0/GmfGD+iqAwUj u5J8xpzcj9qOi/NzHmXiLM/i7s7a+PkuZq+rZgzbcUX14z/enXwloDzXKywlCpyW0UvJPgPBdjQ QYCArgJ/F3luAO+g3ciMlAqrphnxFGWIptVVTVLvo3JgtBkC4+XAILexAxXHrI5J6T8dCyUx7A0 bHOIKjfeze7prPgPaZs6kSQVef988xUoRm2ZE5yQcX6pct8wRSS1hbGpGzF8clYJkd0Zxt4piIH VKspVT1bxsZ/liTHAQYHx3Cs9zaE3y1OuKvgwYyJeYHTy24q115MISG+E0STomQCUpac4+00rqK 0i7iY8Pmte+GsNZutcp0ZpxFsCqiwUh1lja0MDxXXrvtoVArlMfTx0JfjH+cBFbNBKVzJR1Vzw6 NeRTEK6JBTg6r8QjtqXGBSgvHSQMlxiwo/ekhoX7KDKQlmkm/d4JHERrhVrUARjgvQWu8= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 X-Stat-Signature: fe1r9etnsxyf9gxnr9k347rh48ndxaka X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: D7F67C0003 X-Rspam-User: X-HE-Tag: 1788350990-962379 X-HE-Meta: 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 bSEIpeMU PIXBn8trdTQNauuSvdhFtIxUwJDMlhdgLeybAotKQLxilluin1z9dlPhBPmnqtmQUpTfIAqetgr1fderDHNbEFB45GfLYKSA1ZclMXXj9HXj7k4fJliAAtjpL4gv8n62PBJav443UXqyWI/UzFCDtq5ktrBt4RZfLhoyhWLH6cndrs5TZ0ukPULP5InLHEL0fWZvJTM/CkBoC+twun2D/06BUdaPnu4F2xchozjhnw0HWHPmyOxZbGNJLNjac+vjhDxMflAb4xrbl57rLIInYlLoeVw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: There're some random failure for split_huge_page_test when khugepaged collapses pages into pmd again which had split by the test. Prevent the khugepaged's collapses for split page by setting the mapped pmd-huge-page with MADV_NOHUGEPAGE before split. Suggested-by: Kevin Brodsky Suggested-by: Lorenzo Stoakes (ARM) Signed-off-by: Yeoreum Yun --- tools/testing/selftests/mm/split_huge_page_test.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c index 86a603692826..4bbad892bc57 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -168,6 +168,14 @@ static char *allocate_zero_filled_hugepage(size_t len) return result; } +static void madv_nohuge(void *addr, size_t len) +{ + if (!madvise(addr, len, MADV_NOHUGEPAGE)) + return; + + ksft_exit_fail_msg("MADV_NOHUGEPAGE failed, err=%d\n", errno); +} + static void verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int nr_hpages, size_t len) { unsigned long rss_anon_before, rss_anon_after; @@ -180,6 +188,9 @@ static void verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int nr_hp if (!rss_anon_before) ksft_exit_fail_msg("No RssAnon is allocated before split\n"); + /* Prevent khugepaged from collapsing the pages. */ + madv_nohuge(one_page, len); + /* split all THPs */ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, (uint64_t)one_page + len, 0); @@ -227,6 +238,9 @@ static void split_pmd_thp_to_order(int order) if (!check_huge_anon(one_page, 4 * pmd_pagesize, 4, pmd_pagesize)) ksft_exit_fail_msg("No THP is allocated\n"); + /* Prevent khugepaged from collapsing the pages. */ + madv_nohuge(one_page, len); + /* split all THPs */ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, (uint64_t)one_page + len, order); @@ -275,6 +289,9 @@ static void split_pte_mapped_thp(void) goto out; } + /* Prevent khugepaged from collapsing the pages. */ + madv_nohuge(thp_area, thp_area_size); + /* * To challenge spitting code, we will mremap a single page of each * THP (page[i] of thp[i]) in the thp_area into page_area. This will @@ -542,6 +559,8 @@ static int create_pagecache_thp_and_fd(const char *testfile, size_t fd_size, ksft_test_result_skip("Pagecache folio split skipped\n"); return -2; } + /* Prevent khugepaged from collapsing the pages. */ + madv_nohuge(*addr, fd_size); return 0; err_out_close: close(*fd); -- 2.43.0