From ba4f8c355ef96ed521788d6707344f350bf78078 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Wed, 30 Jun 2021 18:48:44 -0700 Subject: [PATCH] userfaultfd/selftests: remove the time() check on delayed uffd There seems to have no guarantee that time() will return the same for the two calls even if there's no delay, e.g. when a fault is accidentally crossing the changing of a second. Meanwhile, this message is also not helping that much since delay could happen with a lot of reasons, e.g., schedule latency of resolving thread. It may not mean an issue with uffd. Neither do I saw this error triggered either in the past runs. Even if it triggers, it'll be drown in all the rest of test logs. Remove it. Link: https://lkml.kernel.org/r/20210412232753.1012412-3-peterx@redhat.com Signed-off-by: Peter Xu Reviewed-by: Axel Rasmussen Cc: Alexander Viro Cc: Andrea Arcangeli Cc: Brian Geffon Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Joe Perches Cc: Kirill A. Shutemov Cc: Lokesh Gidra Cc: Mike Kravetz Cc: Mike Rapoport Cc: Mina Almasry Cc: Oliver Upton Cc: Shaohua Li Cc: Shuah Khan Cc: Stephen Rothwell Cc: Wang Qing Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/selftests/vm/userfaultfd.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index ce23db8eec26..5cae66e27171 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -395,7 +395,6 @@ static void *locking_thread(void *arg) unsigned long long count; char randstate[64]; unsigned int seed; - time_t start; if (bounces & BOUNCE_RANDOM) { seed = (unsigned int) time(NULL) - bounces; @@ -432,7 +431,6 @@ static void *locking_thread(void *arg) page_nr += 1; page_nr %= nr_pages; - start = time(NULL); if (bounces & BOUNCE_VERIFY) { count = *area_count(area_dst, page_nr); if (!count) { @@ -495,12 +493,6 @@ static void *locking_thread(void *arg) count++; *area_count(area_dst, page_nr) = count_verify[page_nr] = count; pthread_mutex_unlock(area_mutex(area_dst, page_nr)); - - if (time(NULL) - start > 1) - fprintf(stderr, - "userfault too slow %ld " - "possible false positive with overcommit\n", - time(NULL) - start); } return NULL; -- 2.11.0