From: Jarek Poplawski <jarkao2@gmail•com>
To: "Paweł Staszewski" <pstaszewski@itcare•pl>
Cc: Eric Dumazet <dada1@cosmosbay•com>,
Eric Dumazet <eric.dumazet@gmail•com>,
Linux Network Development list <netdev@vger•kernel.org>
Subject: Re: weird problem
Date: Sat, 11 Jul 2009 08:24:55 +0200 [thread overview]
Message-ID: <20090711062455.GA3095@ami.dom.local> (raw)
In-Reply-To: <20090710144754.GA25385@ami.dom.local>
On Fri, Jul 10, 2009 at 04:47:54PM +0200, Jarek Poplawski wrote:
> On Fri, Jul 10, 2009 at 01:59:00AM +0200, Paweł Staszewski wrote:
> > Today i make other tests with change of
> > /proc/sys/net/ipv4/rt_cache_rebuild_count and kernel 2.6.30.1
> >
> > And when rt_cache_rebuild_count is set to "-1" i have always load on
> > x86_64 machine approx 40-50% of each cpu where network card is binded by
> > irq_aff
> >
> > when rt_cache_rebuild_count is set to more than "-1" i have 15 to 20 sec
> > of 1 to 3% cpu and after 40-50% cpu
> ...
>
> Here is one more patch for testing (with caution!). It adds possibility
> to turn off cache disabling (so it should even more resemble 2.6.28)
> after setting: rt_cache_rebuild_count = 0
>
> I'd like you to try this patch:
> 1) together with the previous patch and "rt_cache_rebuild_count = 0"
> to check if there is still the difference wrt. 2.6.28; Btw., let
> me know which /proc/sys/net/ipv4/route/* settings do you need to
> change and why
>
> 2) alone (without the previous patch) and "rt_cache_rebuild_count = 0"
>
> 3) if it's possible to try 2.6.30.1 without these patches, but with
> default /proc/sys/net/ipv4/route/* settings, and higher
> rt_cache_rebuild_count, e.g. 100; I'm interested if/how long it
> takes to trigger higher cpu load and the warning "... rebuilds is
> over limit, route caching disabled"; (Btw., I wonder why you didn't
> mention about these or maybe also other route caching warnings?)
Here is take 2 to respect setting "rt_cache_rebuild_count = 0" even
after cache rebuild counter has been increased earlier. (Btw, don't
forget about this setting after going back to vanilla kernel.)
Jarek P.
--- (debugging patch #2 take 2; apply to 2.6.30.1 or 2.6.29.6)
net/ipv4/route.c | 21 ++++++++++++++-------
1 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 278f46f..f74db20 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -678,8 +678,9 @@ static inline u32 rt_score(struct rtable *rt)
static inline bool rt_caching(const struct net *net)
{
- return net->ipv4.current_rt_cache_rebuild_count <=
- net->ipv4.sysctl_rt_cache_rebuild_count;
+ return (net->ipv4.current_rt_cache_rebuild_count <=
+ net->ipv4.sysctl_rt_cache_rebuild_count) ||
+ net->ipv4.sysctl_rt_cache_rebuild_count == 0;
}
static inline bool compare_hash_inputs(const struct flowi *fl1,
@@ -1181,12 +1182,18 @@ restart:
} else {
if (chain_length > rt_chain_length_max) {
struct net *net = dev_net(rt->u.dst.dev);
- int num = ++net->ipv4.current_rt_cache_rebuild_count;
- if (!rt_caching(dev_net(rt->u.dst.dev))) {
- printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
- rt->u.dst.dev->name, num);
+
+ if (net->ipv4.sysctl_rt_cache_rebuild_count > 0) {
+ int num = ++net->ipv4.current_rt_cache_rebuild_count;
+
+ if (!rt_caching(net))
+ printk(KERN_WARNING
+ "%s: %d rebuilds is over limit, "
+ "route caching disabled\n",
+ rt->u.dst.dev->name, num);
+
+ rt_emergency_hash_rebuild(net);
}
- rt_emergency_hash_rebuild(dev_net(rt->u.dst.dev));
}
}
next prev parent reply other threads:[~2009-07-11 6:25 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-25 16:06 weird problem Paweł Staszewski
2009-06-25 16:33 ` Paweł Staszewski
2009-06-25 17:18 ` Paweł Staszewski
2009-06-25 19:45 ` Paweł Staszewski
2009-06-25 20:18 ` Eric Dumazet
2009-06-25 22:23 ` Paweł Staszewski
2009-06-26 8:37 ` Jarek Poplawski
2009-06-26 9:05 ` Jarek Poplawski
2009-06-26 10:19 ` Eric Dumazet
2009-06-26 17:45 ` Paweł Staszewski
2009-06-26 17:57 ` Paweł Staszewski
2009-06-30 6:40 ` Jarek Poplawski
2009-06-30 8:35 ` Paweł Staszewski
2009-06-30 8:36 ` Paweł Staszewski
2009-07-08 22:34 ` Jarek Poplawski
2009-07-09 23:14 ` Paweł Staszewski
2009-07-09 23:59 ` Paweł Staszewski
2009-07-10 14:47 ` Jarek Poplawski
2009-07-11 6:24 ` Jarek Poplawski [this message]
2009-07-13 23:26 ` Paweł Staszewski
2009-07-14 16:24 ` Jarek Poplawski
2009-07-15 20:15 ` Paweł Staszewski
2009-07-15 22:43 ` Jarek Poplawski
2009-07-16 11:01 ` Jarek Poplawski
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