The patch titled Subject: Revert "selftests/mm: replace atomic_bool with pthread_barrier_t" has been added to the -mm mm-hotfixes-unstable branch. Its filename is revert-selftests-mm-replace-atomic_bool-with-pthread_barrier_t.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days
------------------------------------------------------ From: Edward Liaw edliaw@google.com Subject: Revert "selftests/mm: replace atomic_bool with pthread_barrier_t" Date: Fri, 18 Oct 2024 17:17:23 +0000
This reverts commit e61ef21e27e8deed8c474e9f47f4aa7bc37e138c.
uffd_poll_thread may be called by other tests that do not initialize the pthread_barrier, so this approach is not correct. This will revert to using atomic_bool instead.
Link: https://lkml.kernel.org/r/20241018171734.2315053-3-edliaw@google.com Fixes: e61ef21e27e8 ("selftests/mm: replace atomic_bool with pthread_barrier_t") Signed-off-by: Edward Liaw edliaw@google.com Cc: Ryan Roberts ryan.roberts@arm.com Cc: Peter Xu peterx@redhat.com Cc: Shuah Khan shuah@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
tools/testing/selftests/mm/uffd-common.c | 5 ++--- tools/testing/selftests/mm/uffd-common.h | 3 ++- tools/testing/selftests/mm/uffd-unit-tests.c | 14 ++++++-------- 3 files changed, 10 insertions(+), 12 deletions(-)
--- a/tools/testing/selftests/mm/uffd-common.c~revert-selftests-mm-replace-atomic_bool-with-pthread_barrier_t +++ a/tools/testing/selftests/mm/uffd-common.c @@ -18,7 +18,7 @@ bool test_uffdio_wp = true; unsigned long long *count_verify; uffd_test_ops_t *uffd_test_ops; uffd_test_case_ops_t *uffd_test_case_ops; -pthread_barrier_t ready_for_fork; +atomic_bool ready_for_fork;
static int uffd_mem_fd_create(off_t mem_size, bool hugetlb) { @@ -519,8 +519,7 @@ void *uffd_poll_thread(void *arg) pollfd[1].fd = pipefd[cpu*2]; pollfd[1].events = POLLIN;
- /* Ready for parent thread to fork */ - pthread_barrier_wait(&ready_for_fork); + ready_for_fork = true;
for (;;) { ret = poll(pollfd, 2, -1); --- a/tools/testing/selftests/mm/uffd-common.h~revert-selftests-mm-replace-atomic_bool-with-pthread_barrier_t +++ a/tools/testing/selftests/mm/uffd-common.h @@ -33,6 +33,7 @@ #include <inttypes.h> #include <stdint.h> #include <sys/random.h> +#include <stdatomic.h>
#include "../kselftest.h" #include "vm_util.h" @@ -104,7 +105,7 @@ extern bool map_shared; extern bool test_uffdio_wp; extern unsigned long long *count_verify; extern volatile bool test_uffdio_copy_eexist; -extern pthread_barrier_t ready_for_fork; +extern atomic_bool ready_for_fork;
extern uffd_test_ops_t anon_uffd_test_ops; extern uffd_test_ops_t shmem_uffd_test_ops; --- a/tools/testing/selftests/mm/uffd-unit-tests.c~revert-selftests-mm-replace-atomic_bool-with-pthread_barrier_t +++ a/tools/testing/selftests/mm/uffd-unit-tests.c @@ -774,7 +774,7 @@ static void uffd_sigbus_test_common(bool char c; struct uffd_args args = { 0 };
- pthread_barrier_init(&ready_for_fork, NULL, 2); + ready_for_fork = false;
fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK);
@@ -791,9 +791,8 @@ static void uffd_sigbus_test_common(bool if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) err("uffd_poll_thread create");
- /* Wait for child thread to start before forking */ - pthread_barrier_wait(&ready_for_fork); - pthread_barrier_destroy(&ready_for_fork); + while (!ready_for_fork) + ; /* Wait for the poll_thread to start executing before forking */
pid = fork(); if (pid < 0) @@ -834,7 +833,7 @@ static void uffd_events_test_common(bool char c; struct uffd_args args = { 0 };
- pthread_barrier_init(&ready_for_fork, NULL, 2); + ready_for_fork = false;
fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); if (uffd_register(uffd, area_dst, nr_pages * page_size, @@ -845,9 +844,8 @@ static void uffd_events_test_common(bool if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) err("uffd_poll_thread create");
- /* Wait for child thread to start before forking */ - pthread_barrier_wait(&ready_for_fork); - pthread_barrier_destroy(&ready_for_fork); + while (!ready_for_fork) + ; /* Wait for the poll_thread to start executing before forking */
pid = fork(); if (pid < 0) _
Patches currently in -mm which might be from edliaw@google.com are
revert-selftests-mm-fix-deadlock-for-fork-after-pthread_create-on-arm.patch revert-selftests-mm-replace-atomic_bool-with-pthread_barrier_t.patch selftests-mm-fix-deadlock-for-fork-after-pthread_create-with-atomic_bool.patch