lkml.org 
[lkml]   [1997]   [Mar]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: asm/uaccess.h reimplementation, patch. [was: Re: 2.1 kernel bloat revisited]
Date

[Results for access_ok() = 1 , plus dummy push/pop follow ]

> >
> > With access_ok() defined to "1".
> >
> > ------------------------------------------------------------------------
> > Memory: 4192k/5504k available (528k kernel code, 384k reserved, 400k data)
> >
> > 119.980u 77.100s 3:26.28 95.5% 0+0k 0+0io 139pf+0w
> > 118.220u 75.850s 3:22.73 95.7% 0+0k 0+0io 129pf+0w
> > 115.770u 76.050s 3:23.03 94.4% 0+0k 0+0io 131pf+0w
> > ------------------------------------------------------------------------
> >
> >
> > With access_ok() doing what it is supposed to do:
> >
> > ------------------------------------------------------------------------
> > Memory: 4152k/5504k available (564k kernel code, 384k reserved, 404k data)
> >
> > 124.380u 109.470s 4:04.16 95.7% 0+0k 0+0io 187pf+56w
> > 120.510u 111.490s 4:00.93 96.2% 0+0k 0+0io 142pf+0w
> > 119.580u 109.490s 3:58.02 96.2% 0+0k 0+0io 133pf+0w
> > ------------------------------------------------------------------------
>
> ugh. Ok, here is a patch that simulates the syscall overhead of my
> previously mailed %fs scheme (keep access_ok() == 1):

[...]

> very curious what your benchmark says about this one. [btw, the patch adds
> a bit more overhead than necessary]. The patch is untested but if >this<
> patch goes wrong i have to quit hacking for a few days ... :)

Well, with the extra push/pop dummy ops in there, the difference is
nearly lost in the noise:

121.180u 76.660s 3:26.68 95.7% 0+0k 0+0io 137pf+0w
119.840u 76.970s 3:25.48 95.7% 0+0k 0+0io 129pf+0w
117.970u 80.550s 3:30.09 94.4% 0+0k 0+0io 112pf+0w

Avg of 3:24.0 vs. 3:27.4 with a noise of about +/-3 seconds). Still
about 30 sec better than the current access_ok(). Will have to see
if the percent differences are of equal magnitude on 486 boxes, or
if the existence of L1 cache changes things vs. the above 386 #'s.

Paul.

\
 
 \ /
  Last update: 2005-03-22 13:39    [W:0.041 / U:0.696 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site