From 56cfdd46b8bccffecdf0121c1d329b16a3a49906 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 18 Mar 2021 17:01:52 +1100 Subject: [PATCH] FROMGIT: 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 see 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/20210310004511.51996-3-peterx@redhat.com Signed-off-by: Peter Xu Reviewed-by: Axel Rasmussen Cc: Andrea Arcangeli Cc: Nadav Amit Signed-off-by: Andrew Morton Signed-off-by: Stephen Rothwell (cherry picked from commit 9c08bd6a7410e916a8d38e932d913bb240219745 https: //git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm) Link: https://lore.kernel.org/patchwork/patch/1392477/ Signed-off-by: Lokesh Gidra Bug: 160737021 Bug: 169683130 Change-Id: I09b7b75425115653ee6082e7f1846984fba197fe --- 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 b16779fa6e9a..0f003fa27a95 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -558,7 +558,6 @@ 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; @@ -595,7 +594,6 @@ 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) { @@ -658,12 +656,6 @@ 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;