linux-stable.git/tools/testing/selftests/vm/compaction_test.c, branch linux-4.9.y Linux kernel stable tree kselftest: fix OOM in memory compaction test 2018-02-22T14:43:52+00:00 Arnd Bergmann arnd@arndb.de 2018-01-09T16:26:24+00:00 1d808f828f4cc97bd2f7dbafce2e9a33f3d8a86d commit 4c1baad223906943b595a887305f2e8124821dad upstream. Running the compaction_test sometimes results in out-of-memory failures. When I debugged this, it turned out that the code to reset the number of hugepages to the initial value is simply broken since we write into an open sysctl file descriptor multiple times without seeking back to the start. Adding the lseek here fixes the problem. Cc: stable@vger.kernel.org Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Link: https://bugs.linaro.org/show_bug.cgi?id=3145 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4c1baad223906943b595a887305f2e8124821dad upstream.

Running the compaction_test sometimes results in out-of-memory
failures. When I debugged this, it turned out that the code to
reset the number of hugepages to the initial value is simply
broken since we write into an open sysctl file descriptor
multiple times without seeking back to the start.

Adding the lseek here fixes the problem.

Cc: stable@vger.kernel.org
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://bugs.linaro.org/show_bug.cgi?id=3145
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
selftests/vm: write strlen length instead of sizeof to nr_hugepages 2016-06-27T19:18:26+00:00 Yannick Brosseau scientist@fb.com 2016-06-20T15:07:21+00:00 ee65735dd5acecbf335f9aa32e3b129a1de9e184 When setting back the initial value to nr_hugepages, the test was writing a length sizeof of the string and checking that strlen was writen. Since those values are not the same, use strlen in both place instead. Also make the error messages more explicit to help in future debugging. Signed-off-by: Yannick Brosseau <scientist@fb.com> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> 
When setting back the initial value to nr_hugepages, the
test was writing a length sizeof of the string and checking
that strlen was writen. Since those values are not the same,
use strlen in both place instead.

Also make the error messages more explicit to help in future
debugging.

Signed-off-by: Yannick Brosseau <scientist@fb.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Test compaction of mlocked memory 2015-05-26T21:58:06+00:00 Sri Jayaramappa sjayaram@akamai.com 2015-04-23T18:21:41+00:00 bd67d5c15cc190f52eb2f2a2f6f6b800ca33d9dd Commit commit 5bbe3547aa3b ("mm: allow compaction of unevictable pages") introduced a sysctl that allows userspace to enable scanning of locked pages for compaction. This patch introduces a new test which fragments main memory and attempts to allocate a number of huge pages to exercise this compaction logic. Tested on machines with up to 32 GB RAM. With the patch a much larger number of huge pages can be allocated than on the kernel without the patch. Example output: On a machine with 16 GB RAM: sudo make run_tests vm ... ----------------------- running compaction_test ----------------------- No of huge pages allocated = 3834 [PASS] ... Signed-off-by: Sri Jayaramappa <sjayaram@akamai.com> Cc: linux-kernel@vger.kernel.org Cc: linux-api@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Eric B Munson <emunson@akamai.com> Reviewed-by: Eric B Munson <emunson@akamai.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com> 
Commit commit 5bbe3547aa3b ("mm: allow compaction of unevictable pages")
introduced a sysctl that allows userspace to enable scanning of locked
pages for compaction.  This patch introduces a new test which fragments
main memory and attempts to allocate a number of huge pages to exercise
this compaction logic.

Tested on machines with up to 32 GB RAM. With the patch a much larger
number of huge pages can be allocated than on the kernel without the
patch.

Example output:
On a machine with 16 GB RAM:
sudo make run_tests vm
...
-----------------------
running compaction_test
-----------------------
No of huge pages allocated = 3834
[PASS]
...

Signed-off-by: Sri Jayaramappa <sjayaram@akamai.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-api@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric B Munson <emunson@akamai.com>
Reviewed-by: Eric B Munson <emunson@akamai.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>