Re: [LTP] [PATCH 1/3] mm/thp: new case thp04.c

Zhouping Liu
2013-04-08T08:58:20Z

Hi Wanlong,

On 04/08/2013 04:15 PM, Wanlong Gao wrote:
> On 04/08/2013 02:38 PM, Zhouping Liu wrote:
>> The case is desinged to test THP functionality.
>>
>> when one process allocate hugepage aligned anonymouse pages,
>> kernel thread 'khugepaged' controlled by sysfs knobs
>> /sys/kernel/mm/transparent_hugepage/* will scan them, and make
>> them as transparent hugepage if they are suited, you can find out
>> how many transparent hugepages are there in one process from
>> /proc/<pid>/smaps, among the file contents, 'AnonHugePages' entry
>> stand for transparent hugepage.
>>
>> Signed-off-by: Zhouping Liu <zliu@redhat.com>
>> ---
>> runtest/mm | 3 +
>> testcases/kernel/mem/include/mem.h | 11 +++
>> testcases/kernel/mem/lib/mem.c | 180 +++++++++++++++++++++++++++++++++++++
>> testcases/kernel/mem/thp/thp04.c | 136 ++++++++++++++++++++++++++++
>> 4 files changed, 330 insertions(+)
>> create mode 100644 testcases/kernel/mem/thp/thp04.c
>>
>> diff --git a/runtest/mm b/runtest/mm
>> index 56b83f8..3fbb20f 100644
>> --- a/runtest/mm
>> +++ b/runtest/mm
>> @@ -84,6 +84,9 @@ swapping01 swapping01 -i 5
>> thp01 thp01 -I 120
>> thp02 thp02
>> thp03 thp03
>> +thp04_1 thp04
>> +thp04_2 thp04 -n 10 -N 20
>> +thp04_3 thp04 -n 1 -N 300
>>
>> vma01 vma01
>> vma02 vma02
>> diff --git a/testcases/kernel/mem/include/mem.h b/testcases/kernel/mem/include/mem.h
>> index fdf558e..ccae47d 100644
>> --- a/testcases/kernel/mem/include/mem.h
>> +++ b/testcases/kernel/mem/include/mem.h
>> @@ -32,6 +32,17 @@ void testoom(int mempolicy, int lite);
>>
>> #define PATH_KSM "/sys/kernel/mm/ksm/"
>>
>> +/* THP */
>> +
>> +#define PATH_THP "/sys/kernel/mm/transparent_hugepage/"
>> +#define PATH_KHPD PATH_THP "khugepaged/"
>> +
>> +int opt_nr_child, opt_nr_thps;
>> +char *opt_nr_child_str, *opt_nr_thps_str;
>> +void test_transparent_hugepage(int nr_child, int nr_thps, int hg_aligned);
>> +void check_thp_options(int *nr_child, int *nr_thps);
>> +void thp_usage(void);
>> +
>> /* HUGETLB */
>>
>> #define PATH_SHMMAX "/proc/sys/kernel/shmmax"
>> diff --git a/testcases/kernel/mem/lib/mem.c b/testcases/kernel/mem/lib/mem.c
>> index c9525e5..491afe8 100644
>> --- a/testcases/kernel/mem/lib/mem.c
>> +++ b/testcases/kernel/mem/lib/mem.c
>> @@ -501,6 +501,186 @@ void ksm_usage(void)
>> printf(" -u Memory allocation unit in MB\n");
>> }
>>
>> +/* THP */
>> +
>> +static int alloc_transparent_hugepages(int nr_thps, int hg_aligned)
>> +{
>> + unsigned long hugepagesize, size;
>> + void *addr;
>> + int ret;
>> +
>> + hugepagesize = read_meminfo("Hugepagesize:") * KB;
>> + size = nr_thps * hugepagesize;
>> +
>> + if (hg_aligned) {
>> + ret = posix_memalign(&addr, hugepagesize, size);
>> + if (ret != 0) {
>> + printf("posix_memalign failed\n");
>> + return -1;
>> + }
>> + } else {
>> + addr = mmap(NULL, size, PROT_READ|PROT_WRITE,
>> + MAP_PRIVATE|MAP_ANON, -1, 0);
>> + if (addr == MAP_FAILED) {
>> + perror("mmap");
>> + return -1;
>> + }
>> + }
>> +
>> + memset(addr, 10, size);
>> +
>> + tst_resm(TINFO, "child[%d] stop here", getpid());
>> + /*
>> + * stop here, until the father finish to calculate
>> + * all the transparent hugepages.
>> + */
>> + if (raise(SIGSTOP) == -1) {
>> + perror("kill");
>> + return -1;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static void khugepaged_scan_done(void)
>> +{
>> + int changing = 1, count = 0;
>> + long old_pages_collapsed, old_defrag;
>> + long old_max_ptes_none, old_pages_to_scan;
>> + long pages_collapsed = 0, pages_to_scan = 0;
>> + long defrag = 0, max_ptes_none = 0;
>> +
>> + while (changing) {
>> + sleep(10);
> You should comment this sleep line. Why should it be 10?

Wanlong, Thanks for reviewing.

here 10s is similar with one inside wait_ksmd_done() (see lib/mem.c)

10s is an interval for khugepaged to finish scan process's transparent
hugepages, and at the beginning,
khugepaged/[scan_sleep_millisecs|alloc_sleep_millisecs]
are all be set 0, so 'khugepaged' always run 100% during the testing,
depending on
this, I choose an optional value 10s to khugepaged, and I think the
interval is enough
to recognise whether khugepaged finished scanning process's anonymous
hugepage or not.

I will do some comment on V2.

>
>
>> + count++;
>> +
>> + SAFE_FILE_SCANF(cleanup, PATH_KHPD "pages_collapsed",
>> + "%ld", &pages_collapsed);
>> + SAFE_FILE_SCANF(cleanup, PATH_KHPD "defrag", "%ld", &defrag);
>> + SAFE_FILE_SCANF(cleanup, PATH_KHPD "max_ptes_none",
>> + "%ld", &max_ptes_none);
>> + SAFE_FILE_SCANF(cleanup, PATH_KHPD "pages_to_scan",
>> + "%ld", &pages_to_scan);
>> +
>> + if (pages_collapsed != old_pages_collapsed ||
>> + pages_to_scan != old_pages_to_scan ||
>> + max_ptes_none != old_max_ptes_none ||
>> + defrag != old_defrag) {
>> + old_pages_collapsed = pages_collapsed;
>> + old_pages_to_scan = pages_to_scan;
>> + old_max_ptes_none = max_ptes_none;
>> + old_defrag = defrag;
>> + } else {
>> + changing = 0;
>> + }
>> + }
>> +
>> + tst_resm(TINFO, "khugepaged daemon takes %ds to scan all thp pages",
>> + count * 10);
>> +}
>> +
>> +static void verify_thp_size(int *child, int nr_child, int nr_thps)
>> +{
>> + FILE *fp;
>> + char path[BUFSIZ], buf[BUFSIZ], line[BUFSIZ];
>> + int i, ret;
>> + long expect_thps; /* the amount of per child's transparent hugepages */
>> + long val, actual_thps;
>> + long hugepagesize;
>> +
>> + hugepagesize = read_meminfo("Hugepagesize:");
>> + expect_thps = nr_thps * hugepagesize;
>> +
>> + for (i = 0; i < nr_child; i++) {
>> + actual_thps = 0;
>> +
>> + snprintf(path, BUFSIZ, "/proc/%d/smaps", child[i]);
>> + fp = fopen(path, "r");
>> + while (fgets(line, BUFSIZ, fp) != NULL) {
>> + ret = sscanf(line, "%64s %ld", buf, &val);
>> + if (ret == 2 && val != 0) {
>> + if (strcmp(buf, "AnonHugePages:") == 0)
>> + actual_thps += val;
>> + }
>> + }
>> +
>> + if (actual_thps != expect_thps)
>> + tst_resm(TFAIL, "child[%d] got %ldKB thps - expect %ld"
>> + "KB thps", getpid(), actual_thps, expect_thps);
>> + fclose(fp);
>> + }
>> +}
>> +
>> +void test_transparent_hugepage(int nr_child, int nr_thps, int hg_aligned)
>> +{
>> + unsigned long hugepagesize;
>> + int i, *pid, ret, status;
>> + char path[BUFSIZ];
>> +
>> + hugepagesize = read_meminfo("Hugepagesize:");
>> +
>> + pid = (int *)malloc(nr_child * sizeof(int));
> type is unnecessary?

doesn't it need? (I'm not sure)

>
>> + if (pid == NULL)
>> + tst_brkm(TBROK | TERRNO, cleanup, "malloc");
>> +
>> + for (i = 0; i < nr_child; i++) {
>> + switch (pid[i] = fork()) {
>> + case -1:
>> + tst_brkm(TBROK | TERRNO, cleanup, "fork");
>> +
>> + case 0:
>> + ret = alloc_transparent_hugepages(nr_thps, hg_aligned);
>> + exit(ret);
>> + }
>> + }
>> +
>> + tst_resm(TINFO, "Stop all children...");
>> + for (i = 0; i < nr_child; i++) {
>> + if (waitpid(pid[i], &status, WUNTRACED) == -1)
>> + tst_brkm(TBROK|TERRNO, cleanup, "waitpid");
>> + if (!WIFSTOPPED(status))
>> + tst_brkm(TBROK, cleanup,
>> + "child[%d] was not stoppted", pid[i]);
>> + }
>> +
>> + tst_resm(TINFO, "Start to scan all transparent hugepages...");
>> + khugepaged_scan_done();
>> +
>> + tst_resm(TINFO, "Start to verify transparent hugepage size...");
>> + verify_thp_size(pid, nr_child, nr_thps);
>> +
>> + tst_resm(TINFO, "Wake up all children...");
>> + for (i = 0; i < nr_child; i++) {
>> + if (kill(pid[i], SIGCONT) == -1)
>> + tst_brkm(TBROK | TERRNO, cleanup,
>> + "signal continue child[%d]", pid[i]);
>> + }
>> +
>> + /* wait all children finish himself task */
>> + for (i = 0; i < nr_child; i++) {
>> + if (waitpid(pid[i], &status, 0) == -1)
>> + tst_brkm(TBROK|TERRNO, cleanup, "waitpid %d", pid[i]);
>> +
>> + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
>> + tst_resm(TFAIL, "the child[%d] unexpectedly failed:"
>> + " %d", pid[i], status);
>> + }
>> +}
>> +
>> +void check_thp_options(int *nr_child, int *nr_thps)
>> +{
>> + if (opt_nr_child)
>> + *nr_child = SAFE_STRTOL(NULL, opt_nr_child_str, 0, LONG_MAX);
>> + if (opt_nr_thps)
>> + *nr_thps = SAFE_STRTOL(NULL, opt_nr_thps_str, 0, LONG_MAX);
>> +}
>> +
>> +void thp_usage(void)
>> +{
>> + printf(" -n Number of processes\n");
>> + printf(" -N Number of transparent hugepages\n");
>> +}
>> +
>> /* cpuset/memcg */
>>
>> static void gather_node_cpus(char *cpus, long nd)
>> diff --git a/testcases/kernel/mem/thp/thp04.c b/testcases/kernel/mem/thp/thp04.c
>> new file mode 100644
>> index 0000000..2855eb5
>> --- /dev/null
>> +++ b/testcases/kernel/mem/thp/thp04.c
>> @@ -0,0 +1,136 @@
>> +/*
>> + * Copyright (C) 2013 Linux Test Project
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of version 2 of the GNU General Public
>> + * License as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it would be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>> + *
>> + * Further, this software is distributed without any warranty that it
>> + * is free of the rightful claim of any third person regarding
>> + * infringement or the like. Any license provided herein, whether
>> + * implied or otherwise, applies only to this software file. Patent
>> + * licenses, if any, provided herein do not apply to combinations of
>> + * this program with other software, or any other product whatsoever.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, write the Free Software
>> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
>> + * 02110-1301, USA.
>> + */
>> +
>> +/*
>> + * The case is designed to test the functionality of transparent
>> + * hugepage - THP
>> + *
>> + * when one process allocate hugepage aligned anonymouse pages,
>> + * kernel thread 'khugepaged' controlled by sysfs knobs
>> + * /sys/kernel/mm/transparent_hugepage/ will scan them, and make
>> + * them as transparent hugepage if they are suited, you can find out
>> + * how many transparent hugepages are there in one process from
>> + * /proc/<pid>/smaps, among the file contents, 'AnonHugePages' entry
>> + * stand for transparent hugepage.
>> + */
>> +
>> +#include <sys/types.h>
>> +#include <sys/mman.h>
>> +#include <sys/stat.h>
>> +#include <sys/wait.h>
>> +#include <errno.h>
>> +#include <fcntl.h>
>> +#include <signal.h>
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <string.h>
>> +#include <unistd.h>
>> +#include "test.h"
>> +#include "usctest.h"
>> +#include "mem.h"
>> +
>> +char *TCID = "thp04";
>> +int TST_TOTAL = 1;
>> +
>> +option_t thp_options[] = {
>> + {"n:", &opt_nr_child, &opt_nr_child_str},
>> + {"N:", &opt_nr_thps, &opt_nr_thps_str},
>> + {NULL, NULL, NULL}
>> +};
>> +
>> +int pre_thp_scan_sleep_millisecs;
>> +int pre_thp_alloc_sleep_millisecs;
>> +char pre_thp_enabled[BUFSIZ];
> These can be made to static?

yes, they can be static, I will update these on V2.

>
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + int lc;
>> + char *msg;
>> + int nr_child = 2, nr_thps = 64;
>> +
>> + msg = parse_opts(argc, argv, thp_options, thp_usage);
>> + if (msg != NULL)
>> + tst_brkm(TBROK, tst_exit, "OPTION PARSING ERROR - %s", msg);
>> + check_thp_options(&nr_child, &nr_thps);
>> +
>> + setup();
>> +
>> + tst_resm(TINFO, "Start to test transparent hugepage...");
>> + tst_resm(TINFO, "There are %d children allocating %d "
>> + "transparent hugepages", nr_child, nr_thps);
>> +
>> + for (lc = 0; TEST_LOOPING(lc); lc++) {
>> + tst_count = 0;
>> +
>> + test_transparent_hugepage(nr_child, nr_thps, 1);
>> + }
>> +
>> + cleanup();
>> + tst_exit();
>> +}
>> +
>> +void setup(void)
> static ?

no, it declared on include/mem.h.

>
>> +{
>> + char path[BUFSIZ];
>> +
>> + tst_require_root(NULL);
>> +
>> + if (access(PATH_THP, F_OK) == -1)
>> + tst_brkm(TCONF, NULL, "THP is not enabled");
>> +
>> + snprintf(path, BUFSIZ, PATH_KHPD "scan_sleep_millisecs");
>> + SAFE_FILE_SCANF(NULL, path, "%d", &pre_thp_scan_sleep_millisecs);
>> + /* set 0 to khugepaged/scan_sleep_millisecs to run khugepaged 100% */
>> + SAFE_FILE_PRINTF(cleanup, path, "%d", 0);
>> +
>> + snprintf(path, BUFSIZ, PATH_KHPD "alloc_sleep_millisecs");
>> + SAFE_FILE_SCANF(NULL, path, "%d", &pre_thp_alloc_sleep_millisecs);
>> + /*
>> + * set 0 to khugepaged/alloc_sleep_millisecs to make sure khugepaged
>> + * don't stop if there's a hugepage allcation failure.
>> + */
>> + SAFE_FILE_PRINTF(NULL, path, "%d", 0);
>> +
>> + snprintf(path, BUFSIZ, PATH_THP "enabled");
>> + write_file(path, "always");
>> +
>> + tst_sig(FORK, DEF_HANDLER, NULL);
>> + TEST_PAUSE;
>> +}
>> +
>> +void cleanup(void)
> static?

ditto, it's also used by some functions in lib/mem.c.

>
> Thanks,
> Wanlong Gao
>
>
>> +{
>> + char path[BUFSIZ];
>> +
>> + snprintf(path, BUFSIZ, PATH_KHPD "scan_sleep_millisecs");
>> + SAFE_FILE_PRINTF(NULL, path, "%d", pre_thp_scan_sleep_millisecs);
>> +
>> + snprintf(path, BUFSIZ, PATH_KHPD "alloc_sleep_millisecs");
>> + SAFE_FILE_PRINTF(NULL, path, "%d", pre_thp_alloc_sleep_millisecs);
>> +
>> + snprintf(path, BUFSIZ, PATH_THP "enabled");
>> + write_file(path, pre_thp_enabled);
>> +
>> + TEST_CLEANUP;
>> +}
>>