Re: excessive swap-in time

On Sat, 15 Mar 2008 15:25:05 +0000 (UTC) Pierre Asselin <pa@xxxxxxxxxxxxxxxxxxxxx> wrote:
| phil-news-nospam@xxxxxxxx wrote:
|> I sometimes encounter swap-in times for some heavy processes (usually the
|> Firefox browser) that can take a few MINUTES to complete.
|
| You mean when you return to it after leaving it idle for a while ?

Yes. I assume it is up to 100% swapped out.


| There is a control knob in /proc/sys/vm/swappiness that might
| alleviate that. Content is a decimal number from 0 to 100.
| Higher values tell the kernel to swap out idle apps to make more
| room for filesystem caches. Try echoing a low number into it
| and see if it improves overall performance for you.

What does a low number mean? If it means it will leave the process in
RAM, that may not work. The reason is that other processes have caused
this process to swap out, and appropriately so. The issue is not about
the fact that this process is swapped out; it is about doing the swapping
in better. Each swapped out page should only need to be swapped back in
just once, if this is the only active process.

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