Messages in this thread | | | Subject | Re: TCP_STREAM performance regression on commit b3613118 | From | Eric Dumazet <> | Date | Tue, 06 Mar 2012 04:01:28 -0800 |
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Le mardi 06 mars 2012 à 16:26 +0800, Jason Wang a écrit : > On 03/06/2012 04:11 PM, Feng Tang wrote: > > On Thu, Mar 01, 2012 at 10:07:43PM -0500, David Miller wrote: > >> > From: Alex Shi<alex.shi@intel.com> > >> > Date: Fri, 02 Mar 2012 10:45:17 +0800 > >> > > >>> > > Add CC to tang feng, He is working on this issue. > >> > > >> > Is he? I'm pretty sure this is due to the TCP receive window growing > >> > issue Eric Dumazet, Neal Cardwell and I are discussing in the thread > >> > starting at: > >> > > >> > http://marc.info/?l=linux-netdev&m=132916352815286&w=2 > > Yes, probably, as we did find some clue related with the tcp_r/wmem. > > > > Here is the regression we found: > > On some machines, we found there is about 10% resgression of netperf > > TCP-64K loopback test between 3.2 and 3.3-rc1. The exact test is: > > ./netperf -t TCP_STREAM -l 60 -H 127.0.0.1 -i 50,3 -I 99,5 -- -s 32768 -S 32768 -m 4096 > > > > > > The test machine is a 2 socket Quad Core Core 2 Duo server(2.66GHz) with > > 8 GB RAM. Following are the debug info (ifconfig/netstat -s/tcp_rwmem) > > before and after the test: > > > > The most obvious differences I can see are: > > 1) 311 GB vs 241 GB from ifconfig > > 2) the difference of the tcp_r/wmem > > Hi: > > Could you try the newest kernel? Looks like the difference has been > already fixed by commit c43b874d5d714f271b80d4c3f49e05d0cbf51ed2. >
Most likely yes.
tcp_rmem 4096 87380 87380 tcp_wmem 4096 16384 65536
Is way pessimistic :(
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