From mboxrd@z Thu Jan 1 00:00:00 1970 From: Duncan <1i5t5.duncan@cox.net> Subject: Re: [PATCH] btrfs: don't add both copies of DUP to reada extent tree Date: Sat, 25 Feb 2012 08:33:39 +0000 (UTC) Message-ID: References: <1330157387-6803-1-git-send-email-sensille@gmx.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: linux-btrfs@vger.kernel.org Return-path: List-ID: Arne Jansen posted on Sat, 25 Feb 2012 09:09:47 +0100 as excerpted: > Normally when there are 2 copies of a block, we add both to the reada > extent tree and prefetch only the one that is easier to reach. > This way we can better utilize multiple devices. > In case of DUP this makes no sense as both copies reside on the same > device. I'm not a coder and thus can't really read the code to know, but wouldn't the same easier-to-reach logic apply there, only to seeking? One of the DUPs should be easier to reach (less seeking) than the other. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman