dm round robin: use percpu 'repeat_count' and 'current_path'

Browse source

Now that dm-mpath core is lockless in the per-IO fast path it is
critical, for performance, to have the .select_path hook
(rr_select_path) also be as lockless as possible.

The new percpu members of 'struct selector' allow for lockless support
of 'repeat_count' governed repeat use of a previously selected path.  If
a path fails while it is 'current_path' the worst case is concurrent IO
might be mapped to the failed path until the .fail_path hook
(rr_fail_path) is called.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

...

This commit is contained in:

Mike Snitzer 2016-02-17 15:04:05 -05:00

parent 90a4323ccf

commit b0b477c7e0

1 changed files with 48 additions and 12 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

60

drivers/md/dm-round-robin.c

View file