On 2018年02月12日 11:26, Li Zhijian wrote:


On 2018年02月11日 13:44, Li Zhijian wrote:


On 02/10/2018 05:11 AM, Dan Rue wrote:
On Fri, Feb 09, 2018 at 03:53:59PM +0800, Li Zhijian wrote:
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
Hi Zhijian,

Please try this patch in mainline:

     4c1baad22390 kselftest: fix OOM in memory compaction test

Hi Dan

Thanks for your replies.

I run this case on v4.15, looks this patch is already merged to v4.15.
lizhijian@inn:~/linux$ git describe 4c1baad
v4.15-rc2-2-g4c1baad223906

My mistake, this path is not contained by v4.15 yet.
i will have a try.
Hi Dan,

I ran this case on this commit 4c1baad22390, this issue still occurs.

root@ivb44 ~# dmesg | tail -n 30
[  105.825870] main: 247

[  105.825994] main: 242

[  105.826130] main: 247

[  105.826250] main: 242

[  105.826394] main: 247

[  105.826506] main: 242

[  105.826617] main: 247

[  105.826728] main: 242

[  105.826840] main: 247

[  105.826950] main: 250

[  105.827272] check_compaction: 98

[  105.827589] check_compaction: 105

[  105.827849] check_compaction: 111

[  105.828152] check_compaction: 118

[  105.828451] check_compaction: 123


the runtime code is like
-------------------
110
111         fprintf(stderr, "%s: %d\n", __func__, __LINE__);
112         /* Start with the initial condition of 0 huge pages*/
113         if (write(fd, "0", sizeof(char)) != sizeof(char)) {
114                 perror("Failed to write 0 to /proc/sys/vm/nr_hugepages\n");
115                 goto close_fd;
116 }
117
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__);
124         if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) { 125                 perror("Failed to write 100000 to /proc/sys/vm/nr_hugepages\n");
126                 goto close_fd;
127         }
-------------------

Thanks

Thanks




Thanks

Dan


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

Anybody can help have a look?

Thanks
Zhjian



--
To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html

.




Reply via email to