[prev in list] [next in list] [prev in thread] [next in thread] 

List:       freebsd-fs
Subject:    Re: fs cache
From:       Thomas Hurst <tom.hurst () clara ! net>
Date:       2007-06-21 0:35:58
Message-ID: 20070621003558.GA55731 () voi ! aagh ! net
[Download RAW message or body]

* Vlad GURDIGA (gurdiga@gmail.com) wrote:

>  The only difference I can see is that on Ubuntu, after first start of
>  Firefox the memory use for cache is 22% vs. 0% on FreeBSD. My guess is
>  that this is the cause of slower startups on FreeBSD.

If you mean the "Cache" value in top, that's quite normal; "Cache" in
FreeBSD doesn't mean quite the same as it does in Linux -- it's just one
of several queues VM pages churn through depending on usage patterns and
memory pressure.

Most cached data will tend to reside in "Inact", where it's ready for
quick use and modification, and it only cycles to "Cache" when the VM
decides it's worth making clean (flushing to backing store if necessary)
and marking read-only so it can be reused quickly (i.e.  without
touching a disk).

And yes, Ubuntu doubtless does fancy prelinking/binding magic.  This is
a project idea listed on http://www.freebsd.org/projects/ideas/
and has had several attempts in the past from the look of it.

-- 
Thomas 'Freaky' Hurst
    http://hur.st/

[prev in list] [next in list] [prev in thread] [next in thread]