Date: Thu, 27 May 2004 17:45:50 +0200 From: Ivan Voras <ivoras@fer.hr> To: current@freebsd.org Subject: Re: Softupdates a mount option? Message-ID: <40B60D2E.3050003@fer.hr> In-Reply-To: <20040527140744.GW63479@cicely12.cicely.de> References: <40B4ECC8.50808@fer.hr> <20040526202849.GA37162@freebie.xs4all.nl> <40B519DA.7000708@fer.hr> <20040527120819.B8434@gamplex.bde.org> <40B5DE26.4040901@fer.hr> <20040527124512.GV63479@cicely12.cicely.de> <40B5E66F.7000507@fer.hr> <20040527140744.GW63479@cicely12.cicely.de>
next in thread | previous in thread | raw e-mail | index | archive | help
Bernd Walter wrote:
>>>SU makes perfectly sense for swap backed md drives.
>>
>>I always thought the "swap backed" meant the memory is allocated from the
>>same pool as for userland applications, e.g. they only get swapped out if
>>memory is scarce. Is this wrong?
>
>
> You are right, but md(4) doesn't know about the filesystem and therefor
> can't know which blocks have content to keep and which are unused.
> SU now allows files that are deleted quite fast to never touch the
> block device and md never need to write those blocks into swap storage
> as they never got dirty.
As opposed to the 'async' mode?
--
Every sufficiently advanced magic is indistinguishable from technology
- Arthur C Anticlarke
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?40B60D2E.3050003>