On Mon, Mar 25, 2019 at 05:16:20PM -0700, Han Zhou wrote:
> On Mon, Mar 25, 2019 at 4:57 PM Ben Pfaff <b...@ovn.org> wrote:
> >
> > I was seeing a lot of these messages, including a lot of them suppressed
> > by rate-limiting, and I wondered whether any really big messages were
> > being suppressed. By reporting the largest bucket, instead of just every
> > large bucket, it becomes more likely that the truly too-large buckets get
> > reported.
> >
> > (The problem I saw was a false alarm.)
> >
> > Signed-off-by: Ben Pfaff <b...@ovn.org>
> > ---
> > lib/hmap.c | 18 ++++++++++++------
> > 1 file changed, 12 insertions(+), 6 deletions(-)
> >
> > diff --git a/lib/hmap.c b/lib/hmap.c
> > index 1ba4a5716a78..20161698af5d 100644
> > --- a/lib/hmap.c
> > +++ b/lib/hmap.c
> > @@ -1,5 +1,5 @@
> > /*
> > - * Copyright (c) 2008, 2009, 2010, 2012, 2013, 2015 Nicira, Inc.
> > + * Copyright (c) 2008, 2009, 2010, 2012, 2013, 2015, 2019 Nicira, Inc.
> > *
> > * Licensed under the Apache License, Version 2.0 (the "License");
> > * you may not use this file except in compliance with the License.
> > @@ -103,6 +103,7 @@ resize(struct hmap *hmap, size_t new_mask, const char
> > *where)
> > tmp.buckets[i] = NULL;
> > }
> > }
> > + int max_count = 0;
> > for (i = 0; i <= hmap->mask; i++) {
> > struct hmap_node *node, *next;
> > int count = 0;
> > @@ -111,15 +112,20 @@ resize(struct hmap *hmap, size_t new_mask, const char
> > *where)
> > hmap_insert_fast(&tmp, node, node->hash);
> > count++;
> > }
> > - if (count > 5) {
> > - static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10,
> > 10);
> > - COVERAGE_INC(hmap_pathological);
> > - VLOG_DBG_RL(&rl, "%s: %d nodes in bucket (%"PRIuSIZE" nodes,
> > %"PRIuSIZE" buckets)",
> > - where, count, hmap->n, hmap->mask + 1);
> > + if (count > max_count) {
> > + max_count = count;
> > }
> > }
> > hmap_swap(hmap, &tmp);
> > hmap_destroy(&tmp);
> > +
> > + if (max_count > 5) {
> > + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 10);
> > + COVERAGE_INC(hmap_pathological);
> > + VLOG_DBG_RL(&rl, "%s: %d nodes in bucket "
> > + "(%"PRIuSIZE" nodes, %"PRIuSIZE" buckets)",
> > + where, max_count, hmap->n, hmap->mask + 1);
> > + }
> > }
>
> Would it be more helpful in the same log print out how many buckets
> has count > 5? For example, 1 entry with count = 10 maybe is not a big
> deal, but too many entries with count > 5 may indicate bad hashing.
> The new log may not tell this information.
Good idea, I sent out a v2.
_______________________________________________
dev mailing list
d...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
