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| author | Andrea Arcangeli <aarcange@redhat.com> | 2017-10-14 01:57:54 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-10-14 02:18:32 +0300 |
| commit | 7ddd8faf4399ab4f4edad5604eab35f8a87caf02 (patch) | |
| tree | 51d651f20cdf07d8e7f01f8e23e371b5809c352d /tools | |
| parent | 064f0e9302af4f4ab5e9dca03a5a77d6bebfd35e (diff) | |
| download | linux-7ddd8faf4399ab4f4edad5604eab35f8a87caf02.tar.xz | |
userfaultfd: selftest: exercise -EEXIST only in background transfer
I was stress testing some backports and with high load, after some time,
the latest version of the selftest showed some false positive in
connection with the uffdio_copy_retry. This seems to fix it while still
exercising -EEXIST in the background transfer once in a while.
The fork child will quit after the last UFFDIO_COPY is run, so a
repeated UFFDIO_COPY may not return -EEXIST. This change restricts the
-EEXIST stress to the background transfer where the memory can't go away
from under it.
Also updated uffdio_zeropage, so the interface is consistent.
Link: http://lkml.kernel.org/r/20171004171541.1495-2-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/vm/userfaultfd.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index a2c53a3d223d..de2f9ec8a87f 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -397,7 +397,7 @@ static void retry_copy_page(int ufd, struct uffdio_copy *uffdio_copy, } } -static int copy_page(int ufd, unsigned long offset) +static int __copy_page(int ufd, unsigned long offset, bool retry) { struct uffdio_copy uffdio_copy; @@ -418,7 +418,7 @@ static int copy_page(int ufd, unsigned long offset) fprintf(stderr, "UFFDIO_COPY unexpected copy %Ld\n", uffdio_copy.copy), exit(1); } else { - if (test_uffdio_copy_eexist) { + if (test_uffdio_copy_eexist && retry) { test_uffdio_copy_eexist = false; retry_copy_page(ufd, &uffdio_copy, offset); } @@ -427,6 +427,16 @@ static int copy_page(int ufd, unsigned long offset) return 0; } +static int copy_page_retry(int ufd, unsigned long offset) +{ + return __copy_page(ufd, offset, true); +} + +static int copy_page(int ufd, unsigned long offset) +{ + return __copy_page(ufd, offset, false); +} + static void *uffd_poll_thread(void *arg) { unsigned long cpu = (unsigned long) arg; @@ -544,7 +554,7 @@ static void *background_thread(void *arg) for (page_nr = cpu * nr_pages_per_cpu; page_nr < (cpu+1) * nr_pages_per_cpu; page_nr++) - copy_page(uffd, page_nr * page_size); + copy_page_retry(uffd, page_nr * page_size); return NULL; } @@ -779,7 +789,7 @@ static void retry_uffdio_zeropage(int ufd, } } -static int uffdio_zeropage(int ufd, unsigned long offset) +static int __uffdio_zeropage(int ufd, unsigned long offset, bool retry) { struct uffdio_zeropage uffdio_zeropage; int ret; @@ -814,7 +824,7 @@ static int uffdio_zeropage(int ufd, unsigned long offset) fprintf(stderr, "UFFDIO_ZEROPAGE unexpected %Ld\n", uffdio_zeropage.zeropage), exit(1); } else { - if (test_uffdio_zeropage_eexist) { + if (test_uffdio_zeropage_eexist && retry) { test_uffdio_zeropage_eexist = false; retry_uffdio_zeropage(ufd, &uffdio_zeropage, offset); @@ -830,6 +840,11 @@ static int uffdio_zeropage(int ufd, unsigned long offset) return 0; } +static int uffdio_zeropage(int ufd, unsigned long offset) +{ + return __uffdio_zeropage(ufd, offset, false); +} + /* exercise UFFDIO_ZEROPAGE */ static int userfaultfd_zeropage_test(void) { |