From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: [PATCH] tools/libxc: send page-in requests in batches in linux_privcmd_map_foreign_bulk Date: Thu, 26 Jan 2012 18:02:17 +0100 Message-ID: <20120126170217.GA13007@aepfle.de> References: <317844de67b9293a2e45ecd879a1c58a.squirrel@webmail.lagarcavilla.org> <20120126163810.GA9137@aepfle.de> <55d685d4f7e551ab7c854c509a63f895.squirrel@webmail.lagarcavilla.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <55d685d4f7e551ab7c854c509a63f895.squirrel@webmail.lagarcavilla.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andres Lagar-Cavilla Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Thu, Jan 26, Andres Lagar-Cavilla wrote: > >> Why not alloc a separate arr2 array, move the gfn's that failed with > >> ENOENT there, and retry the whole new arr2 block? You only need to > >> allocate arr2 once, to size num. That will batch always, everything. > > > > The errors for gfns are most likely fragmented. Merging the gfns means > > they will get a different addr. So the overall layout of arr and err > > needs to remain the same. > > Ummh yeah, addr is the problem. But as you say, the error for the gfns are > fragmented, so that seriously limits your batching abilities. > You could pass the whole arr sub-segment encompassing the first and last > gfn that failed with ENOENT. Successful maps within that array will be > re-done by the hypervisor, at no correctness cost. I would imagine that > the extra work is offset by the gains, but that remains to be seen. Isnt that what the patch does, find a range of ENOENTs and try that again? Olaf