Re: [patch] memory reclaim more efficiently

From: KOSAKI Motohiro
Date: Sun Jun 22 2008 - 21:48:50 EST


Hi nagano-san,

> In shrink_zone(), system can not return to user mode before it finishes to
> search LRU list. IMHO, it is very wasteful, since the user processes stay
> unnecessarily long time in shrink_zone() loop and application response time
> becomes relatively bad. This patch changes shrink_zone() that it finishes memory
> reclaim when it reclaims enough memory.
>
> the conditions to end searching:
>
> 1. order of request page is 0
> 2. process is not kswapd.
> 3. satisfy the condition to return try_to_free_pages()
> # nr_reclaim > SWAP_CLUSTER_MAX

I have 3 question.

1. Do you have any performance number?
2. I think this patch advocate many try_to_free_pages() called is better than
one try_to_free_page waste long time. right?
and, why do you think so?
3. if this patch improve perfomance, I guess DEF_PRIORITY is
too small on your machine.
if DEF_PRIORITY is proportional to system memory, do your problem are solved?



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/