GFS2: Average in only non-zero round-trip times for congestion stats (0166b197) · Commits · 戴 / test

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>

fs/gfs2/rgrp.c

+7 −3

Original line number	Diff line number	Diff line
		@@ -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];
		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];

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