[Devel] [PATCH RHEL8 COMMIT] userfaultfd: selftests: refactor statistics
Konstantin Khorenko
khorenko at virtuozzo.com
Mon Apr 20 10:34:53 MSK 2020
The commit is pushed to "branch-rh8-4.18.0-80.1.2.vz8.3.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-80.1.2.vz8.3.6
------>
commit 8c741092178ff21cca96830e1b0175997b59464a
Author: Peter Xu <peterx at redhat.com>
Date: Mon Apr 20 10:34:53 2020 +0300
userfaultfd: selftests: refactor statistics
Introduce uffd_stats structure for statistics of the self test, at the
same time refactor the code to always pass in the uffd_stats for either
read() or poll() typed fault handling threads instead of using two
different ways to return the statistic results. No functional change.
With the new structure, it's very easy to introduce new statistics.
Signed-off-by: Peter Xu <peterx at redhat.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Reviewed-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange at redhat.com>
Cc: Bobby Powers <bobbypowers at gmail.com>
Cc: Brian Geffon <bgeffon at google.com>
Cc: David Hildenbrand <david at redhat.com>
Cc: Denis Plotnikov <dplotnikov at virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert at redhat.com>
Cc: Hugh Dickins <hughd at google.com>
Cc: Jerome Glisse <jglisse at redhat.com>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill at shutemov.name>
Cc: Martin Cracauer <cracauer at cons.org>
Cc: Marty McFadden <mcfadden8 at llnl.gov>
Cc: Maya Gokhale <gokhale2 at llnl.gov>
Cc: Mel Gorman <mgorman at suse.de>
Cc: Mike Kravetz <mike.kravetz at oracle.com>
Cc: Pavel Emelyanov <xemul at openvz.org>
Cc: Rik van Riel <riel at redhat.com>
Cc: Shaohua Li <shli at fb.com>
Link: http://lkml.kernel.org/r/20200220163112.11409-19-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
https://jira.sw.ru/browse/PSBM-102938
(cherry picked from commit 5c8aed6c1b95c3c6de68bd2814611d5d54da5057)
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
tools/testing/selftests/vm/userfaultfd.c | 76 ++++++++++++++++++++------------
1 file changed, 49 insertions(+), 27 deletions(-)
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index e987d65b5d43..2f3f1b2b0e51 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -100,6 +100,12 @@ static char *area_src, *area_src_alias, *area_dst, *area_dst_alias;
static char *zeropage;
pthread_attr_t attr;
+/* Userfaultfd test statistics */
+struct uffd_stats {
+ int cpu;
+ unsigned long missing_faults;
+};
+
/* pthread_mutex_t starts at page offset 0 */
#define area_mutex(___area, ___nr) \
((pthread_mutex_t *) ((___area) + (___nr)*page_size))
@@ -115,6 +121,17 @@ pthread_attr_t attr;
~(unsigned long)(sizeof(unsigned long long) \
- 1)))
+static void uffd_stats_reset(struct uffd_stats *uffd_stats,
+ unsigned long n_cpus)
+{
+ int i;
+
+ for (i = 0; i < n_cpus; i++) {
+ uffd_stats[i].cpu = i;
+ uffd_stats[i].missing_faults = 0;
+ }
+}
+
static int anon_release_pages(char *rel_area)
{
int ret = 0;
@@ -457,8 +474,8 @@ static int uffd_read_msg(int ufd, struct uffd_msg *msg)
return 0;
}
-/* Return 1 if page fault handled by us; otherwise 0 */
-static int uffd_handle_page_fault(struct uffd_msg *msg)
+static void uffd_handle_page_fault(struct uffd_msg *msg,
+ struct uffd_stats *stats)
{
unsigned long offset;
@@ -473,18 +490,19 @@ static int uffd_handle_page_fault(struct uffd_msg *msg)
offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst;
offset &= ~(page_size-1);
- return copy_page(uffd, offset);
+ if (copy_page(uffd, offset))
+ stats->missing_faults++;
}
static void *uffd_poll_thread(void *arg)
{
- unsigned long cpu = (unsigned long) arg;
+ struct uffd_stats *stats = (struct uffd_stats *)arg;
+ unsigned long cpu = stats->cpu;
struct pollfd pollfd[2];
struct uffd_msg msg;
struct uffdio_register uffd_reg;
int ret;
char tmp_chr;
- unsigned long userfaults = 0;
pollfd[0].fd = uffd;
pollfd[0].events = POLLIN;
@@ -514,7 +532,7 @@ static void *uffd_poll_thread(void *arg)
msg.event), exit(1);
break;
case UFFD_EVENT_PAGEFAULT:
- userfaults += uffd_handle_page_fault(&msg);
+ uffd_handle_page_fault(&msg, stats);
break;
case UFFD_EVENT_FORK:
close(uffd);
@@ -533,28 +551,27 @@ static void *uffd_poll_thread(void *arg)
break;
}
}
- return (void *)userfaults;
+
+ return NULL;
}
pthread_mutex_t uffd_read_mutex = PTHREAD_MUTEX_INITIALIZER;
static void *uffd_read_thread(void *arg)
{
- unsigned long *this_cpu_userfaults;
+ struct uffd_stats *stats = (struct uffd_stats *)arg;
struct uffd_msg msg;
- this_cpu_userfaults = (unsigned long *) arg;
- *this_cpu_userfaults = 0;
-
pthread_mutex_unlock(&uffd_read_mutex);
/* from here cancellation is ok */
for (;;) {
if (uffd_read_msg(uffd, &msg))
continue;
- (*this_cpu_userfaults) += uffd_handle_page_fault(&msg);
+ uffd_handle_page_fault(&msg, stats);
}
- return (void *)NULL;
+
+ return NULL;
}
static void *background_thread(void *arg)
@@ -570,13 +587,12 @@ static void *background_thread(void *arg)
return NULL;
}
-static int stress(unsigned long *userfaults)
+static int stress(struct uffd_stats *uffd_stats)
{
unsigned long cpu;
pthread_t locking_threads[nr_cpus];
pthread_t uffd_threads[nr_cpus];
pthread_t background_threads[nr_cpus];
- void **_userfaults = (void **) userfaults;
finished = 0;
for (cpu = 0; cpu < nr_cpus; cpu++) {
@@ -585,12 +601,13 @@ static int stress(unsigned long *userfaults)
return 1;
if (bounces & BOUNCE_POLL) {
if (pthread_create(&uffd_threads[cpu], &attr,
- uffd_poll_thread, (void *)cpu))
+ uffd_poll_thread,
+ (void *)&uffd_stats[cpu]))
return 1;
} else {
if (pthread_create(&uffd_threads[cpu], &attr,
uffd_read_thread,
- &_userfaults[cpu]))
+ (void *)&uffd_stats[cpu]))
return 1;
pthread_mutex_lock(&uffd_read_mutex);
}
@@ -627,7 +644,8 @@ static int stress(unsigned long *userfaults)
fprintf(stderr, "pipefd write error\n");
return 1;
}
- if (pthread_join(uffd_threads[cpu], &_userfaults[cpu]))
+ if (pthread_join(uffd_threads[cpu],
+ (void *)&uffd_stats[cpu]))
return 1;
} else {
if (pthread_cancel(uffd_threads[cpu]))
@@ -898,11 +916,11 @@ static int userfaultfd_events_test(void)
{
struct uffdio_register uffdio_register;
unsigned long expected_ioctls;
- unsigned long userfaults;
pthread_t uffd_mon;
int err, features;
pid_t pid;
char c;
+ struct uffd_stats stats = { 0 };
printf("testing events (fork, remap, remove): ");
fflush(stdout);
@@ -929,7 +947,7 @@ static int userfaultfd_events_test(void)
"unexpected missing ioctl for anon memory\n"),
exit(1);
- if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, NULL))
+ if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, &stats))
perror("uffd_poll_thread create"), exit(1);
pid = fork();
@@ -945,13 +963,13 @@ static int userfaultfd_events_test(void)
if (write(pipefd[1], &c, sizeof(c)) != sizeof(c))
perror("pipe write"), exit(1);
- if (pthread_join(uffd_mon, (void **)&userfaults))
+ if (pthread_join(uffd_mon, NULL))
return 1;
close(uffd);
- printf("userfaults: %ld\n", userfaults);
+ printf("userfaults: %ld\n", stats.missing_faults);
- return userfaults != nr_pages;
+ return stats.missing_faults != nr_pages;
}
static int userfaultfd_sig_test(void)
@@ -963,6 +981,7 @@ static int userfaultfd_sig_test(void)
int err, features;
pid_t pid;
char c;
+ struct uffd_stats stats = { 0 };
printf("testing signal delivery: ");
fflush(stdout);
@@ -994,7 +1013,7 @@ static int userfaultfd_sig_test(void)
if (uffd_test_ops->release_pages(area_dst))
return 1;
- if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, NULL))
+ if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, &stats))
perror("uffd_poll_thread create"), exit(1);
pid = fork();
@@ -1020,6 +1039,7 @@ static int userfaultfd_sig_test(void)
close(uffd);
return userfaults != 0;
}
+
static int userfaultfd_stress(void)
{
void *area;
@@ -1028,7 +1048,7 @@ static int userfaultfd_stress(void)
struct uffdio_register uffdio_register;
unsigned long cpu;
int err;
- unsigned long userfaults[nr_cpus];
+ struct uffd_stats uffd_stats[nr_cpus];
uffd_test_ops->allocate_area((void **)&area_src);
if (!area_src)
@@ -1157,8 +1177,10 @@ static int userfaultfd_stress(void)
if (uffd_test_ops->release_pages(area_dst))
return 1;
+ uffd_stats_reset(uffd_stats, nr_cpus);
+
/* bounce pass */
- if (stress(userfaults))
+ if (stress(uffd_stats))
return 1;
/* unregister */
@@ -1201,7 +1223,7 @@ static int userfaultfd_stress(void)
printf("userfaults:");
for (cpu = 0; cpu < nr_cpus; cpu++)
- printf(" %lu", userfaults[cpu]);
+ printf(" %lu", uffd_stats[cpu].missing_faults);
printf("\n");
}
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