tmpfs experimental?

[Dmitry Morozovsky]

On Tue, 16 Jun 2009, Wojciech Puchar wrote:

WP> > > In other words, is there still reason for the "highly experimental
WP> > > feature" warning?
WP> > 
WP> > Last time when I added the warning, it was because some data corruption
WP> > issue that can be identified by fsx which I didn't got a chance to
WP> > investigate further.  I think tmpfs is Ok for some usual work but maybe
WP> > not ready for production at that moment.  alc@ and kib@ has made a lot
WP> > of changes on it recently so perhaps we need to re-visit the problems,
WP> > tmpfs would be a great feature for us.
WP> 
WP> as an ordinary user not programmer of tmpfs i can say that:
WP> 
WP> 1) runs fine for months in production environments, including case with over
WP> 40 mountpoints (jails)
WP> 2) runs really fast when memory is available.
WP> 3) performance is bad in case that swapping actually is used. It reads from
WP> swap with too small chunks. it's a place for improvement here.
WP> 
WP> Its great thing as it does it properly - memory is immediately freed on
WP> delete, and no caching of memory disk like with md(4).

Actually, buffer cache is used, so excessive memory usage are still in place; 
also, on rather heavy tmpfs usage (building large ports, for example) I still 
can panic and/or hang the machione with exhausted maxswzone, so there 
definitely is a place to improve things ;)

-- 
Sincerely,
D.Marck                                     [DM5020, MCK-RIPE, DM3-RIPN]
[ FreeBSD committer:                                 marck at FreeBSD.org ]
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*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck at rinet.ru ***
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