Re: [RFC] mm: remove swapcache page early

From: Simon Jeons
Date: Sun Apr 07 2013 - 21:51:47 EST


On 04/08/2013 09:48 AM, Minchan Kim wrote:
Hello Simon,

On Sun, Apr 07, 2013 at 03:26:12PM +0800, Simon Jeons wrote:
Ping Minchan.
On 04/02/2013 09:40 PM, Simon Jeons wrote:
Hi Hugh,
On 03/28/2013 05:41 AM, Hugh Dickins wrote:
On Wed, 27 Mar 2013, Minchan Kim wrote:

Swap subsystem does lazy swap slot free with expecting the page
would be swapped out again so we can't avoid unnecessary write.
so we can avoid unnecessary write.
If page can be swap out again, which codes can avoid unnecessary
write? Could you point out to me? Thanks in advance. ;-)
Look at shrink_page_list.

1) PageAnon(page) && !PageSwapCache()
2) add_to_swap's SetPageDirty
3) __remove_mapping

P.S)
It seems you are misunderstanding. Here isn't proper place to ask a
question for your understanding the code. As I know, there are some
project(ex, kernelnewbies) and books for study and sharing the
knowledge linux kernel.

I recommend Mel's "Understand the Linux Virtual Memory Manager".
It's rather outdated but will be very helpful to understand VM of
linux kernel. You can get it freely but I hope you pay for.
So if author become a billionaire by selecting best book in Amazon,
he might print out second edition which covers all of new VM features
and may solve all of you curiosity.

It would be a another method to contribute open source project. :)

I believe you talented developers can catch it up with reading the
code enoughly and find more bonus knowledge. I think it's why our senior
developers yell out RTFM and I follow them.

What's the meaning of RTFM?


Cheers!



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