5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Hildenbrand <david@xxxxxxxxxx>
[ Upstream commit c41a701d18efe6b8aa402efab16edbaba50c9548 ]
Currently, running the charge_reserved_hugetlb.sh selftest we can
sometimes observe something like:
$ ./charge_reserved_hugetlb.sh -cgroup-v2
...
write_result is 0
After write:
hugetlb_usage=0
reserved_usage=10485760
killing write_to_hugetlbfs
Received 2.
Deleting the memory
Detach failure: Invalid argument
umount: /mnt/huge: target is busy.
Both cases are issues in the test.
While the unmount error seems to be racy, it will make the test fail:
$ ./run_vmtests.sh -t hugetlb
...
# [FAIL]
not ok 10 charge_reserved_hugetlb.sh -cgroup-v2 # exit=32
The issue is that we are not waiting for the write_to_hugetlbfs process to
quit. So it might still have a hugetlbfs file open, about which umount is
not happy. Fix that by making "killall" wait for the process to quit.
The other error ("Detach failure: Invalid argument") does not seem to
result in a test error, but is misleading. Turns out write_to_hugetlbfs.c
unconditionally tries to cleanup using shmdt(), even when we only
mmap()'ed a hugetlb file. Even worse, shmaddr is never even set for the
SHM case. Fix that as well.
With this change it seems to work as expected.
Link: https://lkml.kernel.org/r/20240821123115.2068812-1-david@xxxxxxxxxx
Fixes: 29750f71a9b4 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Reported-by: Mario Casquero <mcasquer@xxxxxxxxxx>
Reviewed-by: Mina Almasry <almasrymina@xxxxxxxxxx>
Tested-by: Mario Casquero <mcasquer@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/testing/selftests/vm/charge_reserved_hugetlb.sh | 2 -
tools/testing/selftests/vm/write_to_hugetlbfs.c | 21 ++++++++++--------
2 files changed, 13 insertions(+), 10 deletions(-)
--- a/tools/testing/selftests/vm/charge_reserved_hugetlb.sh
+++ b/tools/testing/selftests/vm/charge_reserved_hugetlb.sh
@@ -249,7 +249,7 @@ function cleanup_hugetlb_memory() {
local cgroup="$1"
if [[ "$(pgrep -f write_to_hugetlbfs)" != "" ]]; then
echo killing write_to_hugetlbfs
- killall -2 write_to_hugetlbfs
+ killall -2 --wait write_to_hugetlbfs
wait_for_hugetlb_memory_to_get_depleted $cgroup
fi
set -e
--- a/tools/testing/selftests/vm/write_to_hugetlbfs.c
+++ b/tools/testing/selftests/vm/write_to_hugetlbfs.c
@@ -28,7 +28,7 @@ enum method {
/* Global variables. */
static const char *self;
-static char *shmaddr;
+static int *shmaddr;
static int shmid;
/*
@@ -47,15 +47,17 @@ void sig_handler(int signo)
{
printf("Received %d.\n", signo);
if (signo == SIGINT) {
- printf("Deleting the memory\n");
- if (shmdt((const void *)shmaddr) != 0) {
- perror("Detach failure");
+ if (shmaddr) {
+ printf("Deleting the memory\n");
+ if (shmdt((const void *)shmaddr) != 0) {
+ perror("Detach failure");
+ shmctl(shmid, IPC_RMID, NULL);
+ exit(4);
+ }
+
shmctl(shmid, IPC_RMID, NULL);
- exit(4);
+ printf("Done deleting the memory\n");
}
-
- shmctl(shmid, IPC_RMID, NULL);
- printf("Done deleting the memory\n");
}
exit(2);
}
@@ -211,7 +213,8 @@ int main(int argc, char **argv)
shmctl(shmid, IPC_RMID, NULL);
exit(2);
}
- printf("shmaddr: %p\n", ptr);
+ shmaddr = ptr;
+ printf("shmaddr: %p\n", shmaddr);
break;
default:
