Re: [PATCH RFC] mm readahead: Fix the readahead fail in case of emptynuma node

From: Raghavendra K T
Date: Wed Dec 04 2013 - 04:00:26 EST


On 12/04/2013 02:11 PM, Andrew Morton wrote:
On Wed, 04 Dec 2013 14:00:09 +0530 Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx> wrote:

Unfaortunately, from my search, I saw that the code belonged to pre git
time, so could not get much information on that.

Here: https://lkml.org/lkml/2004/8/20/242

It seems it was done as a rather thoughtless performance optimisation.
I'd say it's time to reimplement max_sane_readahead() from scratch.


Ok. Thanks for the link. I think after that,
Here it was changed to pernode:
https://lkml.org/lkml/2004/8/21/9 to avoid iteration all over.

do you think above patch (+comments) with some sanitized nr (thus
avoiding iteration over nodes in remote numa readahead case) does look
better?
or should we iterate all memory.




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