lkml.org 
[lkml]   [2008]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Active waiting with yield()
On Sat, 15 Nov 2008, Peter Zijlstra wrote:

> On Fri, 2008-11-14 at 16:41 -0500, Mikulas Patocka wrote:
>
> > So, use msleep(1) instead of yield() ?
>
> wait_event() of course!

Why? Why developes don't like active waiting when terminating a driver?
Is there any real workload when 1ms delay on driver unload would be
problematic? Or don't they like it because of coding style?

L1 cache miss --- 10ns --- on every request, when using wait queues
msleep latency --- 1ms --- on driver termination, when using msleep
--- so if the driver processes more than 100000 requests between reboots,
wait queues actually slow things down.

Mikulas


\
 
 \ /
  Last update: 2008-11-17 18:43    [W:0.165 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site