diff options
| author | Bob Peterson <rpeterso@redhat.com> | 2015-04-22 11:24:12 -0500 |
|---|---|---|
| committer | Bob Peterson <rpeterso@redhat.com> | 2015-04-24 07:57:37 -0500 |
| commit | 0166b197c2ed2327bb7761ded8cba2cfd371a425 (patch) | |
| tree | 911dfbac2de1f89baf8b5316ee64c5439fbdab4f | |
| parent | f4a3ae9308e34bcd704325a08879b2c1cfb74686 (diff) | |
GFS2: Average in only non-zero round-trip times for congestion stats
This patch changes function gfs2_rgrp_congested so that it only factors
in non-zero values into its average round trip time. If the round-trip
time is zero for a particular cpu, that cpu has obviously never dealt
with bouncing the resource group in question, so factoring in a zero
value will only skew the numbers. It also fixes a compile error on
some arches related to division.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
| -rw-r--r-- | fs/gfs2/rgrp.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index f39eedc1af76..cb270651c613 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -1854,15 +1854,19 @@ static bool gfs2_rgrp_congested(const struct gfs2_rgrpd *rgd, int loops) s64 srttb_diff; s64 sqr_diff; s64 var; - int cpu; + int cpu, nonzero = 0; preempt_disable(); for_each_present_cpu(cpu) { st = &per_cpu_ptr(sdp->sd_lkstats, cpu)->lkstats[LM_TYPE_RGRP]; - a_srttb += st->stats[GFS2_LKS_SRTTB]; + if (st->stats[GFS2_LKS_SRTTB]) { + a_srttb += st->stats[GFS2_LKS_SRTTB]; + nonzero++; + } } st = &this_cpu_ptr(sdp->sd_lkstats)->lkstats[LM_TYPE_RGRP]; - a_srttb /= num_present_cpus(); + if (nonzero) + do_div(a_srttb, nonzero); r_dcount = st->stats[GFS2_LKS_DCOUNT]; var = st->stats[GFS2_LKS_SRTTVARB] + gl->gl_stats.stats[GFS2_LKS_SRTTVARB]; |