lkml.org 
[lkml]   [2004]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patches in this message
/
From
SubjectRE: Default cache_hot_time value back to 10ms
Date
Andrew Morton wrote on Wednesday, October 06, 2004 1:43 PM
> "Chen, Kenneth W" <kenneth.w.chen@intel.com> wrote:
> >
> > Secondly, let me ask the question again from the first mail thread: this value
> > *WAS* 10 ms for a long time, before the domain scheduler. What's so special
> > about domain scheduler that all the sudden this parameter get changed to 2.5?
>
> So why on earth was it switched from 10 to 2.5 in the first place?
>
> Please resend the final patch.


Here is a patch that revert default cache_hot_time value back to the equivalence
of pre-domain scheduler, which determins task's cache affinity via architecture
defined variable cache_decay_ticks.

This is a mere request that we go back to what *was* before, *NOT* as a new
scheduler tweak (Whatever tweak done for domain scheduler broke traditional/
industry recognized workload).

As a side note, I'd like to get involved on future scheduler tuning experiments,
we have fair amount of benchmark environments where we can validate things across
various kind of workload, i.e., db, java, cpu, etc. Thanks.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>

patch against 2.6.9-rc3:

--- linux-2.6.9-rc3/kernel/sched.c.orig 2004-10-06 15:10:56.000000000 -0700
+++ linux-2.6.9-rc3/kernel/sched.c 2004-10-06 15:18:51.000000000 -0700
@@ -387,7 +387,7 @@ struct sched_domain {
.max_interval = 4, \
.busy_factor = 64, \
.imbalance_pct = 125, \
- .cache_hot_time = (5*1000000/2), \
+ .cache_hot_time = cache_decay_ticks*1000000,\
.cache_nice_tries = 1, \
.per_cpu_gain = 100, \
.flags = SD_BALANCE_NEWIDLE \

patch against 2.6.9-rc3-mm2:

--- linux-2.6.9-rc3/include/linux/topology.h.orig 2004-10-06 15:32:48.000000000 -0700
+++ linux-2.6.9-rc3/include/linux/topology.h 2004-10-06 15:33:25.000000000 -0700
@@ -113,7 +113,7 @@ static inline int __next_node_with_cpus(
.max_interval = 4, \
.busy_factor = 64, \
.imbalance_pct = 125, \
- .cache_hot_time = (5*1000/2), \
+ .cache_hot_time = (cache_decay_ticks*1000),\
.cache_nice_tries = 1, \
.per_cpu_gain = 100, \
.flags = SD_LOAD_BALANCE \


-
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 14:06    [W:0.133 / U:0.152 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site