selftests/powerpc/dscr: Improve DSCR explicit random test case

Browse source

The tests currently have a single writer thread updating the system
DSCR with a 1/1000 chance looped only 100 times. So only around one in
10 runs actually do anything.

* Add multiple threads to the dscr_explicit_random_test case.
* Use a barrier to make all the threads start work as simultaneously as
  possible.
* Use a rwlock and make all threads have a reasonable chance to write to
  the DSCR on each iteration.
  PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP is used to prevent
  writers from starving while all the other threads keep reading.
  Logging the reads/writes shows a decent mix across the whole test.
* Allow all threads a chance to write.
* Make the chance of writing more likely.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230406043320.125138-6-bgray@linux.ibm.com

...

This commit is contained in:

Benjamin Gray 2023-04-06 14:33:18 +10:00 • committed by Michael Ellerman

parent fda8158870

commit 3067b89ab6

3 changed files with 113 additions and 115 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

4

tools/testing/selftests/powerpc/dscr/dscr.h

View file

132

tools/testing/selftests/powerpc/dscr/dscr_default_test.c

View file

94

tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c

View file