lkml.org 
[lkml]   [2007]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: RSDL-mm 0.28
On Sun, Mar 11, 2007 at 01:28:22PM +1100, Con Kolivas wrote:
> >make -j 5 ccache
> > beryl ok good awful
> > galeon good good bad
> > mp3 good good bad
> > terminal good good bad/ok
> > mouse good good bad/ok
...
> >RSDL makes most of the noyield hit back in normal make and then some
> >with ccache. Impressive. But ccache is still destroying interactivity
> >somehow. The ccache effect is fairly visible even with non-parallel
> >'make'.
>
> Ok I don't think there's any actual accounting problem here per se
> (although I did just recently post a bugfix for rsdl however I think
> that's unrelated). What I think is going on in the ccache testcase is
> that all the work is being offloaded to kernel threads reading/writing
> to/from the filesystem and the make is not getting any actual cpu
> time.

I don't see significant system time while this is happening.

> This is "worked around" in mainline thanks to the testing for
> sleeping on uninterruptible sleep in the interactivity estimator. What
> I suspect is happening is kernel threads that are running nice -5 are
> doing all the work on make's behalf in the setting of ccache since it
> is mostly i/o bound. The reason for -nice values on kernel threads is
> questionable anyway. Can you try renicing your kernel threads all to
> nice 0 and see what effect that has? Obviously this doesn't need a
> recompile, but is simple enough to implement in kthread code as a new
> default.

Sorry, little to no benefit.

--
Mathematics is the supreme nostalgia of our time.
-
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: 2007-03-11 05:17    [W:0.240 / U:0.580 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site