lkml.org 
[lkml]   [2012]   [Apr]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC][PATCH] avoid swapping out with swappiness==0
2012/3/30 Satoru Moriya <satoru.moriya@hds.com>:
> Hello Kosaki-san,
>
> On 03/07/2012 01:18 PM, Satoru Moriya wrote:
>> On 03/07/2012 12:19 PM, KOSAKI Motohiro wrote:
>>> Thank you. I brought back to memory it. Unfortunately DB folks are
>>> still mainly using RHEL5 generation distros. At that time,
>>> swapiness=0 doesn't mean disabling swap.
>>>
>>> They want, "don't swap as far as kernel has any file cache page". but
>>> linux don't have such feature. then they used swappiness for emulate
>>> it. So, I think this patch clearly make userland harm. Because of, we
>>> don't have an alternative way.
>
> As I wrote in the previous mail(see below), with this patch
> the kernel begins to swap out when the sum of free pages and
> filebacked pages reduces less than watermark_high.
>
> So the kernel reclaims pages like following.
>
> nr_free + nr_filebacked >= watermark_high: reclaim only filebacked pages
> nr_free + nr_filebacked <  watermark_high: reclaim only anonymous pages

How?
--
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: 2012-04-02 19:13    [W:0.255 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site