[lkml]   [2006]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Subject2.6.19-rc1: Slowdown in lmbench's fork

After introduction of the following patch:

[PATCH] genirq: x86_64 irq: make vector_irq per cpu

we see fork benchmark in lmbench-3.0-a7 slowed by
11.5% on a 2 socket woodcrest machine. Similar change
is seen also on other SMP Xeon machines.

When running lmbench, we have chosen the lmbench option
to pin parent and child on different processor cores

Overhead of calling sched_setaffinity to place the process
on processor is included in lmbench's fork time measurement.
The patch may play a role in increasing this.

The two follow up patches to the original "make vector_irq per cpu"
did not affect the fork time.

[PATCH] x86_64 irq: Properly update vector_irq
[PATCH] x86-64: Only look at per_cpu data for online ...

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-11-02 18:39    [W:0.032 / U:48.144 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site