Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755009Ab0LGJ2A (ORCPT ); Tue, 7 Dec 2010 04:28:00 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:35939 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751823Ab0LGJ16 (ORCPT ); Tue, 7 Dec 2010 04:27:58 -0500 Date: Tue, 7 Dec 2010 04:27:49 -0500 From: Christoph Hellwig To: Mark Lord Cc: Christoph Hellwig , Chris Mason , James Bottomley , Matthew Wilcox , Josef Bacik , Lukas Czerner , tytso , linux-ext4 , linux-kernel , linux-fsdevel , sandeen Subject: Re: [PATCH 1/2] fs: Do not dispatch FITRIM through separate super_operation Message-ID: <20101207092749.GA26100@infradead.org> References: <20101118130630.GJ6178@parisc-linux.org> <20101118134804.GN5618@dhcp231-156.rdu.redhat.com> <20101118141957.GK6178@parisc-linux.org> <20101118142918.GA18510@infradead.org> <1290100750.3041.72.camel@mulgrave.site> <4CE59C9E.6050902@teksavvy.com> <1290177488-sup-6540@think> <4CE68F80.7000607@teksavvy.com> <20101119145748.GB27919@infradead.org> <4CE695FF.20601@teksavvy.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4CE695FF.20601@teksavvy.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1204 Lines: 24 On Fri, Nov 19, 2010 at 10:21:35AM -0500, Mark Lord wrote: > >I really hate to rely on this third party hearsay (from all sides), and > >have implement TRIM support in qemu now. I'll soon install win7 and > >will check out the TRIM patters myself. > > Excellent! I did a Windows 7 installation under qemu today, and the result is: - it TRIMs the whole device early during the installation - after that I see a constant stream of small trims during the installation. It's using lots of non-contiguous ranges in a single TRIM command, with sizes down to 8 sectors (4k) for a single range. - after installation there's is some background-trimming going on even when doing no user interaction with the VM at all. - removing files leads to an instant stream of TRIMs, again vectored and of all sizes down to 4k. Note that the TRIMs are a lot more instant than even with btrfs and -o discard, which delays most TRIMs until doing a sync. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/