[v4,7/8] selftests/mm: refactor uffd_poll_thread to allow custom fault handlers
Commit Message
Previously, we had "one fault handler to rule them all", which used
several branches to deal with all of the scenarios required by all of
the various tests.
In upcoming patches, I plan to add a new test, which has its own
slightly different fault handling logic. Instead of continuing to add
cruft to the existing fault handler, let's allow tests to define custom
ones, separate from other tests.
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
---
tools/testing/selftests/mm/uffd-common.c | 5 ++++-
tools/testing/selftests/mm/uffd-common.h | 3 +++
tools/testing/selftests/mm/uffd-stress.c | 8 ++++----
3 files changed, 11 insertions(+), 5 deletions(-)
Comments
On Fri, Jul 07, 2023 at 02:55:39PM -0700, Axel Rasmussen wrote:
> Previously, we had "one fault handler to rule them all", which used
> several branches to deal with all of the scenarios required by all of
> the various tests.
>
> In upcoming patches, I plan to add a new test, which has its own
> slightly different fault handling logic. Instead of continuing to add
> cruft to the existing fault handler, let's allow tests to define custom
> ones, separate from other tests.
>
> Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
PS: please remember to update manpage after it lands. I still have a plan
to update but not yet happening; if you happen to update before mine please
feel free to update for whatever is missing.
Thanks!
On Sat, Jul 8, 2023 at 8:02 AM Peter Xu <peterx@redhat.com> wrote:
>
> On Fri, Jul 07, 2023 at 02:55:39PM -0700, Axel Rasmussen wrote:
> > Previously, we had "one fault handler to rule them all", which used
> > several branches to deal with all of the scenarios required by all of
> > the various tests.
> >
> > In upcoming patches, I plan to add a new test, which has its own
> > slightly different fault handling logic. Instead of continuing to add
> > cruft to the existing fault handler, let's allow tests to define custom
> > ones, separate from other tests.
> >
> > Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
>
> Acked-by: Peter Xu <peterx@redhat.com>
>
> PS: please remember to update manpage after it lands. I still have a plan
> to update but not yet happening; if you happen to update before mine please
> feel free to update for whatever is missing.
Will do!
>
> Thanks!
>
> --
> Peter Xu
>
@@ -499,6 +499,9 @@ void *uffd_poll_thread(void *arg)
int ret;
char tmp_chr;
+ if (!args->handle_fault)
+ args->handle_fault = uffd_handle_page_fault;
+
pollfd[0].fd = uffd;
pollfd[0].events = POLLIN;
pollfd[1].fd = pipefd[cpu*2];
@@ -527,7 +530,7 @@ void *uffd_poll_thread(void *arg)
err("unexpected msg event %u\n", msg.event);
break;
case UFFD_EVENT_PAGEFAULT:
- uffd_handle_page_fault(&msg, args);
+ args->handle_fault(&msg, args);
break;
case UFFD_EVENT_FORK:
close(uffd);
@@ -77,6 +77,9 @@ struct uffd_args {
unsigned long missing_faults;
unsigned long wp_faults;
unsigned long minor_faults;
+
+ /* A custom fault handler; defaults to uffd_handle_page_fault. */
+ void (*handle_fault)(struct uffd_msg *msg, struct uffd_args *args);
};
struct uffd_test_ops {
@@ -189,10 +189,8 @@ static int stress(struct uffd_args *args)
locking_thread, (void *)cpu))
return 1;
if (bounces & BOUNCE_POLL) {
- if (pthread_create(&uffd_threads[cpu], &attr,
- uffd_poll_thread,
- (void *)&args[cpu]))
- return 1;
+ if (pthread_create(&uffd_threads[cpu], &attr, uffd_poll_thread, &args[cpu]))
+ err("uffd_poll_thread create");
} else {
if (pthread_create(&uffd_threads[cpu], &attr,
uffd_read_thread,
@@ -250,6 +248,8 @@ static int userfaultfd_stress(void)
struct uffd_args args[nr_cpus];
uint64_t mem_size = nr_pages * page_size;
+ memset(args, 0, sizeof(struct uffd_args) * nr_cpus);
+
if (uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED, NULL))
err("context init failed");