lkml.org 
[lkml]   [2006]   [Nov]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectSluggish system responsiveness on I/O
Date
Hello lkml!

Im currently testing 2.6.19-rc5-mm1. Everything works really fine except the
little wart with bad multimedia interactivity with a kernel compiling in the
background. So I tried to narrow it down as much
as possible.

I did several find's,dd's and cats in parrallel and watched four instances of
glxgears and also played a little enemy-territory. The interactivity was very
good, in fact no loss of interactivity at all. This was contrary to what I
believed the whole time. The loss of interactivity has nothing to do with
heavy I/O. In fact it happens only when I run a task which is I/O and CPU
heavy at the same time. That means a single kernel compile (with -j1) is able
to harm interactivity with glxgears and enemy-territory, but fully loading my
three disks does no harm at all.

So I tried to nice the make and see what happens:

nice 5 make -j4: Seems to make no difference. Heavy stuttering in glxgears and
et
nice 10 make -j4: Somewhat better but still unusable with et

everything above nice 15 is usable. nice 19 has full interactivity, that means
you can't make out a difference between no load and kernel compile while
playing enemy-territory.

I suspect that it has something to do with the priority boost for I/O hogs.
But if this is a "general" scheduler problem, then why aren't more people
complaining about this?

-Christian
-
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: 2006-11-18 14:17    [W:0.072 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site