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* [kselftests] compaction_test is blocked
@ 2018-02-09  7:53 Li Zhijian
  2018-02-09 21:11 ` Dan Rue
  0 siblings, 1 reply; 5+ messages in thread
From: Li Zhijian @ 2018-02-09  7:53 UTC (permalink / raw)
  To: linux-kselftest; +Cc: Li, Philip, linux-kernel, Li Zhijian(intel)

Hi

kselftests is integrated Intel 0Day project.
Sometimes we found compaction_test is blocked for more than 1 hours until i kill it.

Try to figure out where it is running, i added some log to this case.

the test log is like:
-------------------
  [  111.750543] main: 248
  [  111.750544]-
  [ 111.750821] check_compaction: 98
  [  111.750822]-
  [  111.751102] check_compaction: 105
  [  111.751103]-
  [  111.751362] check_compaction: 111
  [  111.751363]-
  [  111.751621] check_compaction: 118
  [  111.751622]-
  [  111.751879] check_compaction: 123
  [  111.751880]-
-------------------
118         fprintf(stderr, "%s: %d\n", __func__, __LINE__);
119         lseek(fd, 0, SEEK_SET);
120
121         /* Request a large number of huge pages. The Kernel will allocate
122            as much as it can */
123         fprintf(stderr, "%s: %d\n", __func__, __LINE__);         <<<======== the last line we can catch.
124         if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) {        <<<<============ blocking position
125                 perror("Failed to write 100000 to /proc/sys/vm/nr_hugepages\n");
126                 goto close_fd;
127         }
128
129         lseek(fd, 0, SEEK_SET);
130
131         fprintf(stderr, "%s: %d\n", __func__, __LINE__);
132         if (read(fd, nr_hugepages, sizeof(nr_hugepages)) <= 0) {
133                 perror("Failed to re-read from /proc/sys/vm/nr_hugepages\n");
134                 goto close_fd;
135         }
-------------------

According to above log and code, it most likely it is blocking at the writing operation.

my environment is like:
OS: debian
kernel: v4.15
model: Ivytown Ivy Bridge-EP
nr_cpu: 48
memory: 64G


NOTE: 0Day can reproduce this issue in 20% on 0Day.

Anybody can help have a look?

Thanks
Zhjian




^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2018-02-12  9:58 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-02-09  7:53 [kselftests] compaction_test is blocked Li Zhijian
2018-02-09 21:11 ` Dan Rue
2018-02-11  5:44   ` Li Zhijian
2018-02-12  3:26     ` Li Zhijian
2018-02-12  9:58       ` Li Zhijian

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