lkml.org 
[lkml]   [2009]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4] zone_reclaim is always 0 by default
Acked-by: Robin Holt <holt@sgi.com>


On Thu, Jun 04, 2009 at 07:23:15PM +0900, KOSAKI Motohiro wrote:
...
> Actually, zone_reclaim_mode=1 mean "I dislike remote node allocation rather than
> disk access", it makes performance improvement to HPC workload.
> but it makes performance degression to desktop, file server and web server.

I still disagree with this statement, but I don't care that much.
Why not something more to the effect of:

Setting zone_reclaim_mode=1 causes memory allocations on a nearly
exhausted node to do direct reclaim within that node before attempting
off-node allocations. For work loads where most pages are clean in
page cache and easily reclaimed, this can result excessive disk activity
versus a more fair node memory balance.

If you disagree, don't respond, just ignore.

...
> --- a/include/linux/topology.h
> +++ b/include/linux/topology.h
> @@ -54,12 +54,7 @@ int arch_update_cpu_topology(void);
> #define node_distance(from,to) ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
> #endif
> #ifndef RECLAIM_DISTANCE
> -/*
> - * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
> - * (in whatever arch specific measurement units returned by node_distance())
> - * then switch on zone reclaim on boot.
> - */
> -#define RECLAIM_DISTANCE 20
> +#define RECLAIM_DISTANCE INT_MAX

Why remove this comment? It seems more-or-less a reasonable statement.

Thanks,
Robin


\
 
 \ /
  Last update: 2009-06-04 14:27    [W:0.072 / U:0.140 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site