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From: Dipankar Sarma <dipankar@in.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: davem@redhat.com
Subject: 16-CPU #s for lockfree rtcache (rt_rcu)
Date: Fri, 17 May 2002 19:21:16 +0530	[thread overview]
Message-ID: <20020517192116.G12631@in.ibm.com> (raw)

As promised, here is the kernprof data from the simulated
test suggested by Dave. The test uses 32 processes and dest
addresses for rtcache lookup are random, changing after every 5 packets.
The measurements were done in a 16 CPU NUMA-Q.

2.5.3 : ip_route_output_key [c01bab8c]: 12166
2.5.3+rt_rcu : ip_route_output_key [c01bb084]: 6027

I have seen moderately significant profile counts
for ip_route_input() in preliminary webserver benchmark runs.
It is not however clear to me that bucket lock cache line
bouncing is the reason behind it. That one needs more investigation.

Thanks
-- 
Dipankar Sarma  <dipankar@in.ibm.com> http://lse.sourceforge.net
Linux Technology Center, IBM Software Lab, Bangalore, India.

             reply	other threads:[~2002-05-17 13:48 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-05-17 13:51 Dipankar Sarma [this message]
2002-05-17 13:49 ` 16-CPU #s for lockfree rtcache (rt_rcu) David S. Miller
2002-05-17 16:14   ` Dipankar Sarma
2002-05-17 16:46     ` David S. Miller
2002-05-17 19:25       ` Andi Kleen
2002-05-17 19:25         ` David S. Miller
2002-05-17 20:33           ` Dipankar Sarma

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