Re: [PATCH] mm: add MM_SWAPENTS and page table when calculate tasksize in lowmem_scan()

From: David Rientjes
Date: Mon Feb 22 2016 - 19:50:17 EST


On Thu, 18 Feb 2016, Xishi Qiu wrote:

> How about kill more processes at one time?
>
> Usually loading camera will alloc 300-500M memory immediately, so call lmk
> repeatedly is a waste of time.
>
> And can we reclaim memory at one time instead of reclaim-alloc-reclaim-alloc...
> in this situation? e.g. use try_to_free_pages(), set nr_to_reclaim=300M
>

I don't use the lmk myself and it's never been used on my phone, so I
can't speak for the usecase. However, killing more than one process at a
time is generally a bad idea because it can allow processes to deplete
memory reserves which may be small on these systems. The lmk cannot be
considered a hotpath, so waiting for a process to exit and free its memory
for a small amount of time is generally not a bad trade-off when the
alternative is to kill many processes (perhaps unnecessarily), open
yourself up to livelock, and free memory that is potentially unneeded.