[Omake] Inotify

[Jason Hickey]

Aleksey Nogin wrote:
> On 25.05.2006 19:42, Jason Hickey wrote:
> 
>> We use file notifications a lot, and it looks like inotify looks much 
>> nicer/more-efficient than fam/gamin.
> 
> 
> This is IMHO a false contrast - Gamin does have an inotify backend 
> (which is the default on systems that support it).

Maybe so.  What it does offer is direct kernel-level notification at low 
cost.  What it doesn't offer is the polling that gamin provides on 
remote filesystems.

We pay a fairly high cost to gamin.  Look at the top stats sometime, 
large compilations with -P are usually much slower than without, with 
the gamin deamon taking major time.  I imagine this is better with 
kernel-level notifications, no evidence though.

Not that I'm necessarily suggesting we move away from it.  Gamin offers 
a nice abstraction.  Still, I'd like to see a comparison.

BTW, of course I found (dumb me), that Fedora kernels do support 
inotify, just not transparently.

Jason

-- 
Jason Hickey                  http://www.cs.caltech.edu/~jyh
Caltech Computer Science      Tel: 626-395-6568 FAX: 626-792-4257