[lkml]   [2010]   [Apr]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: hackbench regression due to commit 9dfc6e68bfe6e
From: Eric Dumazet <>
Date: Thu, 08 Apr 2010 09:00:19 +0200

> If run individually, the tests results are more what we would expect
> (slow), but if machine runs the two set of process concurrently, each
> group runs much faster...

BTW, I just discovered (thanks to the function graph tracer, woo hoo!)
that loopback TCP packets get fully checksum validated on receive.

I'm trying to figure out why skb->ip_summed ends up being
CHECKSUM_NONE in tcp_v4_rcv() even though it gets set to
CHECKSUM_PARTIAL in tcp_sendmsg().

I wonder how much this accounts for some of the hackbench
oddities... and other regressions in loopback tests we've seen.

Just FYI...

 \ /
  Last update: 2010-04-08 09:09    [W:0.035 / U:5.944 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site