Re: 2.6.7-ck1

From: Con Kolivas
Date: Sat Jun 19 2004 - 00:25:13 EST


Con Kolivas wrote:
On Sat, 19 Jun 2004 02:28, Felipe Alfaro Solana wrote:

On Wed, 2004-06-16 at 21:22 +1000, Con Kolivas wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Patchset update. The focus of this patchset is on system responsiveness
with emphasis on desktops, but the scope of scheduler changes now makes
this patch suitable to servers as well.

I've found some interaction problems between, what I think it's, the
staircase scheduler and swsusp. With vanilla 2.6.7, swsusp is able to
save ~9000 pages to disk in less than 5 seconds, where as 2.6.7-ck1
takes more than 1 minute to save the same amount of pages when
suspending to disk.


If you're using -ck1 it may even be the autoswappiness. Try disabling that and setting a static value for swappiness. If it still exhibits the problem then it's probably a bug somewhere in staircase. While the overall design is finished (it doesn't really lend itself to tuning), surely there are bugs I haven't sorted out even though there are no serious bugs or stability issues that have come up. I'm auditing the code as we speak.

You might want to try the attached patch which addresses an issue with kernel threads that is going into staircase 7.1

Con --- linux-2.6.7-ck2pre/kernel/sched.c 2004-06-19 15:12:15.280924354 +1000
+++ linux-2.6.7-ck1/kernel/sched.c 2004-06-19 14:58:08.000000000 +1000
@@ -334,8 +334,7 @@ static int effective_prio(task_t *p)

if (used_slice < first_slice)
return prio;
- if (p->mm)
- prio += 1 + (used_slice - first_slice) / rr;
+ prio += 1 + (used_slice - first_slice) / rr;
if (prio > MAX_PRIO - 2)
prio = MAX_PRIO - 2;
return prio;