From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Masover Subject: Re: reiser4 and laptop_mode Date: Mon, 17 Oct 2005 18:04:01 -0500 Message-ID: <43542DE1.7050700@slaphack.com> References: <19812996093.20051017162429@usu.ru> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <19812996093.20051017162429@usu.ru> List-Id: Content-Type: text/plain; charset="us-ascii" To: Sinitsyn Valentine Cc: reiserfs-list@namesys.com Sinitsyn Valentine wrote: > Hi all, > > I'm considering installing Reiser4 on my laptop, but I also want to > use laptop_mode (http://www.xs4all.nl/~bsamwel/laptop_mode/index.html) > to save battery power. So I'm wondering wether these two products are > compatible with each other? I know that Reiser3 and ext3 did require > special patches (now included in mainstream kernels) which schedule > commits in a way which allows hard drive to spin down. I've looked > through Google and this mailing list but didn't find any references to > similar patches for Reiser4. Are they needed but nobody wrote them yet > or is Reiser4 spindown-friendly just out of the box? Reiser4 is spindown-friendly in one way -- until you run out of RAM, it won't commit. In fact, if you have enough RAM, you won't ever touch the disk -- deleting a file before it's committed means it never touches disk. It is not as spindown-friendly as laptop_mode, which notices when the drive has to spin up anyway (maybe through a read) and flushes all writes. Don't know if they are compatible.