Re: PATCH: allow percentile size of tmpfs (2.5.66 / 2.4.20-pre2)

[Ed Tomlinson <tomlins@cam.org>]

CaT wrote:

> I believe the patch below will apply to both the above (I know it does
> to 2.5.66 and 2.4.20-pre2 mm/shmem.c does not look any different so it
> should be fine. :)
> 
> Anyways, what this patch does is allow you to specify the max amount of
> memory tmpfs can use as a percentage of available real ram. This (in my
> eyes) is useful so that you do not have to remember to change the
> setting if you want something other then 50% and some of your ram does
> (and you can't replacew it immediately).
> 
> Usage of this option is as follows:
> 
> tmpfs      /dev/shm tmpfs  rw,size=63%,noauto            0 0
> 
> This is taken from my working system and sets the tmpfs size to 63% of
> my real RAM (256MB). The end result is:
> 
> Filesystem           1k-blocks      Used Available Use% Mounted on
> /dev/shm/tmp            160868      6776    154092   5% /tmp
> 
> I've also tested remounting to silly values (and sane ones) and it all
> works fine with no oopses or freezes and the correct values appearing
> in df.
> 
> All up I feel safer using this then a hard value.

What does tmpfs have to do with ram size?  Its swappable.  This _might_ be
useful for ramfs but for tmpfs, IMHO, its not a good idea.

Ed Tomlinson