From: Suresh K C suresh.k.chandrappa@gmail.com
This patch merges the previous two patches into a single, cohesive test case that verifies cachestat behavior with memory-mapped files using mmap(). It also refactors the test logic to reduce redundancy, improve error reporting, and clarify failure messages for both shmem and mmap file types.
Changes since v2:
- Merged the two patches into one as suggested - Improved error messages for better clarity
Tested on x86_64 with default kernel config.
Signed-off-by: Suresh K C suresh.k.chandrappa@gmail.com --- .../selftests/cachestat/test_cachestat.c | 66 +++++++++++++++---- 1 file changed, 55 insertions(+), 11 deletions(-)
diff --git a/tools/testing/selftests/cachestat/test_cachestat.c b/tools/testing/selftests/cachestat/test_cachestat.c index 632ab44737ec..18188d7c639e 100644 --- a/tools/testing/selftests/cachestat/test_cachestat.c +++ b/tools/testing/selftests/cachestat/test_cachestat.c @@ -33,6 +33,11 @@ void print_cachestat(struct cachestat *cs) cs->nr_evicted, cs->nr_recently_evicted); }
+enum file_type { + FILE_MMAP, + FILE_SHMEM +}; + bool write_exactly(int fd, size_t filesize) { int random_fd = open("/dev/urandom", O_RDONLY); @@ -201,8 +206,19 @@ static int test_cachestat(const char *filename, bool write_random, bool create, out: return ret; } +const char* file_type_str(enum file_type type) { + switch (type) { + case FILE_SHMEM: + return "shmem"; + case FILE_MMAP: + return "mmap"; + default: + return "unknown"; + } +}
-bool test_cachestat_shmem(void) + +bool run_cachestat_test(enum file_type type) { size_t PS = sysconf(_SC_PAGESIZE); size_t filesize = PS * 512 * 2; /* 2 2MB huge pages */ @@ -212,27 +228,49 @@ bool test_cachestat_shmem(void) char *filename = "tmpshmcstat"; struct cachestat cs; bool ret = true; + int fd; unsigned long num_pages = compute_len / PS; - int fd = shm_open(filename, O_CREAT | O_RDWR, 0600); + if (type == FILE_SHMEM) + fd = shm_open(filename, O_CREAT | O_RDWR, 0600); + else + fd = open(filename, O_RDWR | O_CREAT | O_TRUNC, 0666);
if (fd < 0) { - ksft_print_msg("Unable to create shmem file.\n"); + ksft_print_msg("Unable to create %s file.\n",file_type_str(type)); ret = false; goto out; }
if (ftruncate(fd, filesize)) { - ksft_print_msg("Unable to truncate shmem file.\n"); + ksft_print_msg("Unable to truncate %s file.\n",file_type_str(type)); ret = false; goto close_fd; } - - if (!write_exactly(fd, filesize)) { - ksft_print_msg("Unable to write to shmem file.\n"); - ret = false; - goto close_fd; + switch (type){ + case FILE_SHMEM: + if (!write_exactly(fd, filesize)) { + ksft_print_msg("Unable to write to file.\n"); + ret = false; + goto close_fd; + } + break; + case FILE_MMAP: + char *map = mmap(NULL, filesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + if (map == MAP_FAILED) { + ksft_print_msg("mmap failed.\n"); + ret = false; + goto close_fd; + } + for (int i = 0; i < filesize; i++) { + map[i] = 'A'; + } + break; + default: + ksft_print_msg("Unsupported file type.\n"); + ret = false; + goto close_fd; + break; } - syscall_ret = syscall(__NR_cachestat, fd, &cs_range, &cs, 0);
if (syscall_ret) { @@ -308,12 +346,18 @@ int main(void) break; }
- if (test_cachestat_shmem()) + if (run_cachestat_test(FILE_SHMEM)) ksft_test_result_pass("cachestat works with a shmem file\n"); else { ksft_test_result_fail("cachestat fails with a shmem file\n"); ret = 1; }
+ if (run_cachestat_test(FILE_MMAP)) + ksft_test_result_pass("cachestat works with a mmap file\n"); + else { + ksft_test_result_fail("cachestat fails with a mmap file\n"); + ret = 1; + } return ret; }