From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: [PATCH v3 1/1] tools/hotplug: Scan xenstore once when attaching shared images files Date: Wed, 7 Oct 2015 12:52:02 +0100 Message-ID: <1444218722.1410.19.camel@citrix.com> References: <8d0a030929832dca3b26449b2de4ff57d07707af.1443794896.git.mlatimer@suse.com> <22034.43037.80464.987570@mariner.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <22034.43037.80464.987570@mariner.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Jackson , Mike Latimer Cc: George.Dunlap@eu.citrix.com, stefano.stabellini@eu.citrix.com, wei.liu2@citrix.com, roger.pau@citrix.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Mon, 2015-10-05 at 17:41 +0100, Ian Jackson wrote: > Mike Latimer writes ("[PATCH v3 1/1] tools/hotplug: Scan xenstore once > when attaching shared images files"): > > During the attachment of a loopback mounted image file, the mode of all > > curent instances of this device already attached to other domains must > > be > > checked. This requires finding all loopback devices pointing to the > > inode > > of the shared image file, and then comparing the major and minor number > > of > > these devices to the major and minor number of every vbd device found > > in the > > xenstore database. > > > > Prior to this patch, the entire xenstore database is walked for every > > instance > > of every loopback device pointing to the same shared image file. This > > process > > causes the block attachment process to becomes exponentially slower > > with every > > additional attachment of a shared image. > > > > Rather than scanning all of xenstore for every instance of a shared > > loopback > > device, this patch creates a list of the major and minor numbers from > > all > > matching loopback devices. After generating this list, Xenstore is > > walked > > once, and major and minor numbers from every vbd are checked against > > the list. > > If a match is found, the mode of that vbd is checked for compatibility > > with > > the mode of the device being attached. > > Acked-by: Ian Jackson Applied. Mike, FWIW for singleton patches it is normally ok to dispense with the 0/1 mail and to just send the patch by itself. If there is commentary which doesn't belong in the commit message you can put it below a "---" marker (and "git am" will strip it). If there is lots commentary then sending a 0/1 is fine if you want, of course. Ian.