Re: mmap() versus read()

Pavel Machek (pavel@elf.ucw.cz)
Wed, 11 Mar 1998 14:07:39 +0100


Hi!

> [context: paging executables from origin; why not swap?]
> > Ok. Is there easy way to change it? On my system, swap is order of
> > magnitude faster than disk. I would like linux to take advantage of
> > it.
>
> There isn't an easy way to change it right now, unless you want to give up
> the sharing of clean pages, which is a big loss. One option will be
> to

Hmm - looks like I lost sharing of clean change by my hack: I let
swap_state.c set page->inode to swapper_inode even it was already set
to some executable's inode. It really did not work too well.

> take a swap backed inode (I'm using such beasts to replace the SysV shm
> objects) and use it to 'cache' the executable - this would be easy enough
> to accomplish, but could be a potentially heavy user of swap. It does
> have the benefit of also caching normal file access... (say, NFS ;-)

Caching normal files in swap would be _real_ win in case of NFS. (And
definitely over _my_ NFS doing 50k/sec at best :-).

I can not imagine too well how would you free swap in this case.

Pavel

I'm really pavel@atrey.karlin.mff.cuni.cz. Pavel
Look at http://atrey.karlin.mff.cuni.cz/~pavel/ ;-).

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu