diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2018-07-03 20:13:27 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2018-07-27 15:24:22 -0400 |
| commit | 724376a04d1a63d145fdfe7b24c0b13128a3ffd6 (patch) | |
| tree | 517522cfdf4adc4dbc3c4d2487e1d68a592aac23 /tools/perf/scripts/python/call-graph-from-sql.py | |
| parent | 518748b1a744c496a657a5a7923e49e002a6f259 (diff) | |
dm integrity: implement fair range locks
dm-integrity locks a range of sectors to prevent concurrent I/O or journal
writeback. These locks were not fair - so that many small overlapping I/Os
could starve a large I/O indefinitely.
Fix this by making the range locks fair. The ranges that are waiting are
added to the list "wait_list". If a new I/O overlaps some of the waiting
I/Os, it is not dispatched, but it is also added to that wait list.
Entries on the wait list are processed in first-in-first-out order, so
that an I/O can't starve indefinitely.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'tools/perf/scripts/python/call-graph-from-sql.py')
0 files changed, 0 insertions, 0 deletions