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authorBob Peterson <rpeterso@redhat.com>2015-04-22 11:24:12 -0500
committerBob Peterson <rpeterso@redhat.com>2015-04-24 07:57:37 -0500
commit0166b197c2ed2327bb7761ded8cba2cfd371a425 (patch)
tree911dfbac2de1f89baf8b5316ee64c5439fbdab4f /fs/gfs2/rgrp.c
parentf4a3ae9308e34bcd704325a08879b2c1cfb74686 (diff)
downloadlinux-0166b197c2ed2327bb7761ded8cba2cfd371a425.tar.bz2
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>
Diffstat (limited to 'fs/gfs2/rgrp.c')
-rw-r--r--fs/gfs2/rgrp.c10
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];