lkml.org 
[lkml]   [2007]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC] Limit the size of the pagecache
On Wed, 24 Jan 2007 14:15:10 +0900
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:

> - One for stability
> When a customer constructs their detabase(Oracle), the system often goes to oom.
> This is because that the system cannot allocate DMA_ZOME memory for 32bit device.
> (USB or e100)
> Not allowing to use almost all pages as page cache (for temporal use) will be some help.
> (Note: construction DB on ext3....so all writes are serialized and the system couldn't
> free page cache.)

I'm surprised that any reasonable driver has a dependency on ZONE_DMA. Are
you sure? Send full oom-killer output, please.


> - One for tuing.
> Sometimes our cutomer requests us to limit size of page-cache.
>
> Many cutomers's memory usage reaches 99.x%. (this is very common situation.)
> If almost all memories are used by page-cache, and we can think we can free it.
> But the customer cannot estimate what amount of page-cache can be freed (without
> perfromance regression).
>
> When a cutomer wants to add a new application, he tunes the system.
> But memory usage is always 99%.
> page-cache limitation is useful when the customer tunes his system and find
> sets of data and page-cache.
> (Of course, we can use some other complicated resource management system for this.)
> This will allow the users to decide that they need extra memory or not.
>
> And...some customers want to keep memory Free as much as possible.
> 99% memory usage makes insecure them ;)

Tell them to do "echo 3 > /proc/sys/vm/drop_caches", then wait three minutes?
-
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: 2007-01-26 11:39    [W:0.069 / U:0.448 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site