16-CPU #s for lockfree rtcache (rt_rcu)

From: Dipankar Sarma (dipankar@in.ibm.com)
Date: Fri May 17 2002 - 08:51:16 EST

Next message: Richard B. Johnson: "Re: Aralion and IDE blasphemy"
Previous message: Norman Walsh: "Re: Kernel PCMCIA/CardBus on a Tecra 8200"
Next in thread: David S. Miller: "Re: 16-CPU #s for lockfree rtcache (rt_rcu)"
Reply: David S. Miller: "Re: 16-CPU #s for lockfree rtcache (rt_rcu)"
Maybe reply: Andi Kleen: "Re: 16-CPU #s for lockfree rtcache (rt_rcu)"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

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.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Next message: Richard B. Johnson: "Re: Aralion and IDE blasphemy"
Previous message: Norman Walsh: "Re: Kernel PCMCIA/CardBus on a Tecra 8200"
Next in thread: David S. Miller: "Re: 16-CPU #s for lockfree rtcache (rt_rcu)"
Reply: David S. Miller: "Re: 16-CPU #s for lockfree rtcache (rt_rcu)"
Maybe reply: Andi Kleen: "Re: 16-CPU #s for lockfree rtcache (rt_rcu)"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

This archive was generated by hypermail 2b29 : Thu May 23 2002 - 22:00:14 EST