lkml.org 
[lkml]   [2003]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: pdflush question...
From
Date
On Wed, 2003-09-03 at 05:24, Daniel Blueman wrote:
> Is it worth having a kernel config option to vary the number of 'pdflush'
> kernel threads?

I suspect no.

> For embedded, systems with no swap and maybe uniproc (?), perhaps one
> pdflush kthread would do?

Yes. Definitely. In fact, I think that, for all systems, the initial
default should perhaps be one.

But note that the reason for n>1 pdflush threads is neither swap or
processor related. The multiple threads can keep multiple block devices
busy, since one thread blocking on I/O will not affect another one.

I guess the real test would be to set MIN_PDFLUSH_THREADS to one and see
if one is enough for the average machines. If the number quickly jumps
to 2 or more... then we know its a bad idea.

> Perhaps more generally, the number could be linked to the number of
> processors and/or swap devices or spindles- this would eliminate having to configure
> it, and improve downward and upward scaling, perhaps?

Number of spindles, yes. But how do we know that? And its just the
number of busy spindles, really.

I say we drop down to one.

Robert Love


-
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 13:48    [from the cache]
©2003-2011 Jasper Spaans