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| author | James Simmons <jsimmons@infradead.org> | 2017-01-28 19:05:26 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-03 13:01:38 +0100 |
| commit | 86df59846c924c2339603f4370779581e594d0e1 (patch) | |
| tree | ee50820d4fae30b47639e0cf0ddb922cc36b37a1 | |
| parent | 1cf96da241f489fd29fe564c8fc045e51b5269b8 (diff) | |
| download | op-kernel-dev-86df59846c924c2339603f4370779581e594d0e1.zip op-kernel-dev-86df59846c924c2339603f4370779581e594d0e1.tar.gz | |
staging: lustre: osc: avoid 64 divide in osc_cache_too_much
The use of 64 bit time introduces an expensive 64 bit
division operation. Since the time lapse being calculated
in osc_cache_too_much will never be more than seventy years
we can cast the time lapse to an long and perform a normal
32 bit divison operation instead.
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8835
Reviewed-on: https://review.whamcloud.com/23814
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/lustre/lustre/osc/osc_page.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c index 0461408..ab9d0d7 100644 --- a/drivers/staging/lustre/lustre/osc/osc_page.c +++ b/drivers/staging/lustre/lustre/osc/osc_page.c @@ -370,12 +370,17 @@ static int osc_cache_too_much(struct client_obd *cli) return lru_shrink_min(cli); } else { time64_t duration = ktime_get_real_seconds(); + long timediff; /* knock out pages by duration of no IO activity */ duration -= cli->cl_lru_last_used; - duration >>= 6; /* approximately 1 minute */ - if (duration > 0 && - pages >= div64_s64((s64)budget, duration)) + /* + * The difference shouldn't be more than 70 years + * so we can safely case to a long. Round to + * approximately 1 minute. + */ + timediff = (long)(duration >> 6); + if (timediff > 0 && pages >= budget / timediff) return lru_shrink_min(cli); } return 0; |
