lkml.org 
[lkml]   [2001]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: strange nonmonotonic behavior of gettimeoftheday -- seen similar problem on PPC
On Fri, 2 Mar 2001, Richard B. Johnson wrote:

> Yes and no. It takes microseconds to call the kernel for anything (time
> getpid() ), so it seldom loops. All the kernel has to do is remember

Hi,

c0109286 system_call +<22/40> (0.21) pid(4265)
c011c7e7 sys_gettimeofday +<13/a8> (0.27) pid(4265)
c010e3b2 do_gettimeofday +<e/88> (0.48) pid(4265)
c01092aa ret_from_sys_call +<6/21> (0.76) pid(4265)
c0109286 system_call +<22/40> (0.19) pid(4265)
c0120b45 sys_getpid +<d/1c> (0.18) pid(4265)
c01092aa ret_from_sys_call +<6/21> (0.77) pid(4265)
^^^^ time in usecs

This is a 500Mhz PIII. It wouldn't take much more cpu/memory speed
to get under a usec. The overhead of calling the kernel on this box
is almost exactly 1 usec.

-Mike

-
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/

\
 
 \ /
  Last update: 2005-03-22 13:29    [W:0.037 / U:0.848 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site