Message ID | 6d0caab00d4bdccf5e3791cb95cf6dfd5eb85e45.1626252248.git.zhansayabagdaulet@gmail.com |
---|---|
State | Accepted |
Commit | 39619982c5be6ed57390f17aabee6bc11e4af37e |
Headers | show |
Series | add KSM selftests | expand |
On Wed, Jul 14, 2021 at 4:56 AM Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com> wrote: > > Add check_ksm_zero_page_merge() function to test that empty pages are > being handled properly. For this, several zero pages are allocated and > merged using madvise. If use_zero_pages is enabled, the pages must be > shared with the special kernel zero pages; otherwise, they are merged > as usual duplicate pages. The test is run as follows: ./ksm_tests -Z > > Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
On 2021-07-14 14:56:14, Zhansaya Bagdauletkyzy wrote: > Add check_ksm_zero_page_merge() function to test that empty pages are > being handled properly. For this, several zero pages are allocated and > merged using madvise. If use_zero_pages is enabled, the pages must be > shared with the special kernel zero pages; otherwise, they are merged > as usual duplicate pages. The test is run as follows: ./ksm_tests -Z > > Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Tyler > --- > tools/testing/selftests/vm/ksm_tests.c | 70 ++++++++++++++++++++++- > tools/testing/selftests/vm/run_vmtests.sh | 32 +++++++++++ > 2 files changed, 99 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c > index 80302bb8f64c..5843526471e1 100644 > --- a/tools/testing/selftests/vm/ksm_tests.c > +++ b/tools/testing/selftests/vm/ksm_tests.c > @@ -12,6 +12,7 @@ > #define KSM_SCAN_LIMIT_SEC_DEFAULT 120 > #define KSM_PAGE_COUNT_DEFAULT 10l > #define KSM_PROT_STR_DEFAULT "rw" > +#define KSM_USE_ZERO_PAGES_DEFAULT false > > struct ksm_sysfs { > unsigned long max_page_sharing; > @@ -25,7 +26,8 @@ struct ksm_sysfs { > > enum ksm_test_name { > CHECK_KSM_MERGE, > - CHECK_KSM_UNMERGE > + CHECK_KSM_UNMERGE, > + CHECK_KSM_ZERO_PAGE_MERGE > }; > > static int ksm_write_sysfs(const char *file_path, unsigned long val) > @@ -80,10 +82,12 @@ static int str_to_prot(char *prot_str) > > static void print_help(void) > { > - printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n"); > + printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n" > + "[-z use_zero_pages]\n"); > > printf("Supported <test type>:\n" > " -M (page merging)\n" > + " -Z (zero pages merging)\n" > " -U (page unmerging)\n\n"); > > printf(" -a: specify the access protections of pages.\n" > @@ -93,6 +97,8 @@ static void print_help(void) > " Default: %ld\n", KSM_PAGE_COUNT_DEFAULT); > printf(" -l: limit the maximum running time (in seconds) for a test.\n" > " Default: %d seconds\n", KSM_SCAN_LIMIT_SEC_DEFAULT); > + printf(" -z: change use_zero_pages tunable\n" > + " Default: %d\n", KSM_USE_ZERO_PAGES_DEFAULT); > > exit(0); > } > @@ -289,6 +295,50 @@ static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_siz > return KSFT_FAIL; > } > > +static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int timeout, > + bool use_zero_pages, size_t page_size) > +{ > + void *map_ptr; > + struct timespec start_time; > + > + if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) { > + perror("clock_gettime"); > + return KSFT_FAIL; > + } > + > + if (ksm_write_sysfs(KSM_FP("use_zero_pages"), use_zero_pages)) > + return KSFT_FAIL; > + > + /* fill pages with zero and try to merge them */ > + map_ptr = allocate_memory(NULL, prot, mapping, 0, page_size * page_count); > + if (!map_ptr) > + return KSFT_FAIL; > + > + if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout)) > + goto err_out; > + > + /* > + * verify that the right number of pages are merged: > + * 1) if use_zero_pages is set to 1, empty pages are merged > + * with the kernel zero page instead of with each other; > + * 2) if use_zero_pages is set to 0, empty pages are not treated specially > + * and merged as usual. > + */ > + if (use_zero_pages && !assert_ksm_pages_count(0)) > + goto err_out; > + else if (!use_zero_pages && !assert_ksm_pages_count(page_count)) > + goto err_out; > + > + printf("OK\n"); > + munmap(map_ptr, page_size * page_count); > + return KSFT_PASS; > + > +err_out: > + printf("Not OK\n"); > + munmap(map_ptr, page_size * page_count); > + return KSFT_FAIL; > +} > + > int main(int argc, char *argv[]) > { > int ret, opt; > @@ -298,8 +348,9 @@ int main(int argc, char *argv[]) > size_t page_size = sysconf(_SC_PAGESIZE); > struct ksm_sysfs ksm_sysfs_old; > int test_name = CHECK_KSM_MERGE; > + bool use_zero_pages = KSM_USE_ZERO_PAGES_DEFAULT; > > - while ((opt = getopt(argc, argv, "ha:p:l:MU")) != -1) { > + while ((opt = getopt(argc, argv, "ha:p:l:z:MUZ")) != -1) { > switch (opt) { > case 'a': > prot = str_to_prot(optarg); > @@ -321,11 +372,20 @@ int main(int argc, char *argv[]) > case 'h': > print_help(); > break; > + case 'z': > + if (strcmp(optarg, "0") == 0) > + use_zero_pages = 0; > + else > + use_zero_pages = 1; > + break; > case 'M': > break; > case 'U': > test_name = CHECK_KSM_UNMERGE; > break; > + case 'Z': > + test_name = CHECK_KSM_ZERO_PAGE_MERGE; > + break; > default: > return KSFT_FAIL; > } > @@ -359,6 +419,10 @@ int main(int argc, char *argv[]) > ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, > page_size); > break; > + case CHECK_KSM_ZERO_PAGE_MERGE: > + ret = check_ksm_zero_page_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, > + ksm_scan_limit_sec, use_zero_pages, page_size); > + break; > } > > if (ksm_restore(&ksm_sysfs_old)) { > diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh > index 3a23c6b47da2..9b4e444fc4ed 100755 > --- a/tools/testing/selftests/vm/run_vmtests.sh > +++ b/tools/testing/selftests/vm/run_vmtests.sh > @@ -409,6 +409,38 @@ else > exitcode=1 > fi > > +echo "----------------------------------------------------------" > +echo "running KSM test with 10 zero pages and use_zero_pages = 0" > +echo "----------------------------------------------------------" > +./ksm_tests -Z -p 10 -z 0 > +ret_val=$? > + > +if [ $ret_val -eq 0 ]; then > + echo "[PASS]" > +elif [ $ret_val -eq $ksft_skip ]; then > + echo "[SKIP]" > + exitcode=$ksft_skip > +else > + echo "[FAIL]" > + exitcode=1 > +fi > + > +echo "----------------------------------------------------------" > +echo "running KSM test with 10 zero pages and use_zero_pages = 1" > +echo "----------------------------------------------------------" > +./ksm_tests -Z -p 10 -z 1 > +ret_val=$? > + > +if [ $ret_val -eq 0 ]; then > + echo "[PASS]" > +elif [ $ret_val -eq $ksft_skip ]; then > + echo "[SKIP]" > + exitcode=$ksft_skip > +else > + echo "[FAIL]" > + exitcode=1 > +fi > + > exit $exitcode > > exit $exitcode > -- > 2.25.1 >
diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c index 80302bb8f64c..5843526471e1 100644 --- a/tools/testing/selftests/vm/ksm_tests.c +++ b/tools/testing/selftests/vm/ksm_tests.c @@ -12,6 +12,7 @@ #define KSM_SCAN_LIMIT_SEC_DEFAULT 120 #define KSM_PAGE_COUNT_DEFAULT 10l #define KSM_PROT_STR_DEFAULT "rw" +#define KSM_USE_ZERO_PAGES_DEFAULT false struct ksm_sysfs { unsigned long max_page_sharing; @@ -25,7 +26,8 @@ struct ksm_sysfs { enum ksm_test_name { CHECK_KSM_MERGE, - CHECK_KSM_UNMERGE + CHECK_KSM_UNMERGE, + CHECK_KSM_ZERO_PAGE_MERGE }; static int ksm_write_sysfs(const char *file_path, unsigned long val) @@ -80,10 +82,12 @@ static int str_to_prot(char *prot_str) static void print_help(void) { - printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n"); + printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n" + "[-z use_zero_pages]\n"); printf("Supported <test type>:\n" " -M (page merging)\n" + " -Z (zero pages merging)\n" " -U (page unmerging)\n\n"); printf(" -a: specify the access protections of pages.\n" @@ -93,6 +97,8 @@ static void print_help(void) " Default: %ld\n", KSM_PAGE_COUNT_DEFAULT); printf(" -l: limit the maximum running time (in seconds) for a test.\n" " Default: %d seconds\n", KSM_SCAN_LIMIT_SEC_DEFAULT); + printf(" -z: change use_zero_pages tunable\n" + " Default: %d\n", KSM_USE_ZERO_PAGES_DEFAULT); exit(0); } @@ -289,6 +295,50 @@ static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_siz return KSFT_FAIL; } +static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int timeout, + bool use_zero_pages, size_t page_size) +{ + void *map_ptr; + struct timespec start_time; + + if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) { + perror("clock_gettime"); + return KSFT_FAIL; + } + + if (ksm_write_sysfs(KSM_FP("use_zero_pages"), use_zero_pages)) + return KSFT_FAIL; + + /* fill pages with zero and try to merge them */ + map_ptr = allocate_memory(NULL, prot, mapping, 0, page_size * page_count); + if (!map_ptr) + return KSFT_FAIL; + + if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout)) + goto err_out; + + /* + * verify that the right number of pages are merged: + * 1) if use_zero_pages is set to 1, empty pages are merged + * with the kernel zero page instead of with each other; + * 2) if use_zero_pages is set to 0, empty pages are not treated specially + * and merged as usual. + */ + if (use_zero_pages && !assert_ksm_pages_count(0)) + goto err_out; + else if (!use_zero_pages && !assert_ksm_pages_count(page_count)) + goto err_out; + + printf("OK\n"); + munmap(map_ptr, page_size * page_count); + return KSFT_PASS; + +err_out: + printf("Not OK\n"); + munmap(map_ptr, page_size * page_count); + return KSFT_FAIL; +} + int main(int argc, char *argv[]) { int ret, opt; @@ -298,8 +348,9 @@ int main(int argc, char *argv[]) size_t page_size = sysconf(_SC_PAGESIZE); struct ksm_sysfs ksm_sysfs_old; int test_name = CHECK_KSM_MERGE; + bool use_zero_pages = KSM_USE_ZERO_PAGES_DEFAULT; - while ((opt = getopt(argc, argv, "ha:p:l:MU")) != -1) { + while ((opt = getopt(argc, argv, "ha:p:l:z:MUZ")) != -1) { switch (opt) { case 'a': prot = str_to_prot(optarg); @@ -321,11 +372,20 @@ int main(int argc, char *argv[]) case 'h': print_help(); break; + case 'z': + if (strcmp(optarg, "0") == 0) + use_zero_pages = 0; + else + use_zero_pages = 1; + break; case 'M': break; case 'U': test_name = CHECK_KSM_UNMERGE; break; + case 'Z': + test_name = CHECK_KSM_ZERO_PAGE_MERGE; + break; default: return KSFT_FAIL; } @@ -359,6 +419,10 @@ int main(int argc, char *argv[]) ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, page_size); break; + case CHECK_KSM_ZERO_PAGE_MERGE: + ret = check_ksm_zero_page_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, + ksm_scan_limit_sec, use_zero_pages, page_size); + break; } if (ksm_restore(&ksm_sysfs_old)) { diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh index 3a23c6b47da2..9b4e444fc4ed 100755 --- a/tools/testing/selftests/vm/run_vmtests.sh +++ b/tools/testing/selftests/vm/run_vmtests.sh @@ -409,6 +409,38 @@ else exitcode=1 fi +echo "----------------------------------------------------------" +echo "running KSM test with 10 zero pages and use_zero_pages = 0" +echo "----------------------------------------------------------" +./ksm_tests -Z -p 10 -z 0 +ret_val=$? + +if [ $ret_val -eq 0 ]; then + echo "[PASS]" +elif [ $ret_val -eq $ksft_skip ]; then + echo "[SKIP]" + exitcode=$ksft_skip +else + echo "[FAIL]" + exitcode=1 +fi + +echo "----------------------------------------------------------" +echo "running KSM test with 10 zero pages and use_zero_pages = 1" +echo "----------------------------------------------------------" +./ksm_tests -Z -p 10 -z 1 +ret_val=$? + +if [ $ret_val -eq 0 ]; then + echo "[PASS]" +elif [ $ret_val -eq $ksft_skip ]; then + echo "[SKIP]" + exitcode=$ksft_skip +else + echo "[FAIL]" + exitcode=1 +fi + exit $exitcode exit $exitcode
Add check_ksm_zero_page_merge() function to test that empty pages are being handled properly. For this, several zero pages are allocated and merged using madvise. If use_zero_pages is enabled, the pages must be shared with the special kernel zero pages; otherwise, they are merged as usual duplicate pages. The test is run as follows: ./ksm_tests -Z Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com> --- tools/testing/selftests/vm/ksm_tests.c | 70 ++++++++++++++++++++++- tools/testing/selftests/vm/run_vmtests.sh | 32 +++++++++++ 2 files changed, 99 insertions(+), 3 deletions(-)