The patch titled
Subject: userfaultfd/selftests: remove the time() check on delayed uffd
has been added to the -mm tree. Its filename is
userfaultfd-selftests-remove-the-time-check-on-delayed-uffd.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-selftests-remove-the-time-check-on-delayed-uffd.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-selftests-remove-the-time-check-on-delayed-uffd.patch
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------------------------------------------------------
From: Peter Xu <peterx@xxxxxxxxxx>
Subject: 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@xxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/userfaultfd.c | 8 --------
1 file changed, 8 deletions(-)
--- a/tools/testing/selftests/vm/userfaultfd.c~userfaultfd-selftests-remove-the-time-check-on-delayed-uffd
+++ a/tools/testing/selftests/vm/userfaultfd.c
@@ -568,7 +568,6 @@ 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;
@@ -605,7 +604,6 @@ 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) {
@@ -668,12 +666,6 @@ 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;
_
Patches currently in -mm which might be from peterx@xxxxxxxxxx are
hugetlb-dedup-the-code-to-add-a-new-file_region.patch
hugetlg-break-earlier-in-add_reservation_in_range-when-we-can.patch
mm-introduce-page_needs_cow_for_dma-for-deciding-whether-cow.patch
mm-use-is_cow_mapping-across-tree-where-proper.patch
hugetlb-do-early-cow-when-page-pinned-on-src-mm.patch
hugetlb-pass-vma-into-huge_pte_alloc-and-huge_pmd_share.patch
hugetlb-pass-vma-into-huge_pte_alloc-and-huge_pmd_share-fix.patch
hugetlb-userfaultfd-forbid-huge-pmd-sharing-when-uffd-enabled.patch
hugetlb-userfaultfd-forbid-huge-pmd-sharing-when-uffd-enabled-fix.patch
mm-hugetlb-move-flush_hugetlb_tlb_range-into-hugetlbh.patch
hugetlb-userfaultfd-unshare-all-pmds-for-hugetlbfs-when-register-wp.patch
userfaultfd-selftests-use-user-mode-only.patch
userfaultfd-selftests-remove-the-time-check-on-delayed-uffd.patch
userfaultfd-selftests-dropping-verify-check-in-locking_thread.patch
userfaultfd-selftests-only-dump-counts-if-mode-enabled.patch
userfaultfd-selftests-unify-error-handling.patch
