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| author |   NeilBrown <neilb@suse.com> | 2016-06-02 16:19:53 +1000 |
|---|---|---|
| committer |   Shaohua Li <shli@fb.com> | 2016-06-13 11:54:22 -0700 |
| commit | d787be4092e27728cb4c012bee9762098ef3c662 (patch) | |
| tree | b8de57ed842d3c01f6fdd4f6ee5be6408763a993 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | md: be extra careful not to take a reference to a Faulty device. (diff) | |
| download | wireguard-linux-d787be4092e27728cb4c012bee9762098ef3c662.tar.xz wireguard-linux-d787be4092e27728cb4c012bee9762098ef3c662.zip | |
md: reduce the number of synchronize_rcu() calls when multiple devices fail.
Every time a device is removed with ->hot_remove_disk() a synchronize_rcu() call is made
which can delay several milliseconds in some case.
If lots of devices fail at once - as could happen with a large RAID10 where one set
of devices are removed all at once - these delays can add up to be very inconcenient.
As failure is not reversible we can check for that first, setting a
separate flag if it is found, and then all synchronize_rcu() once for
all the flagged devices. Then ->hot_remove_disk() function can skip the
synchronize_rcu() step if the flag is set.
fix build error(Shaohua)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions