From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zdenek Kabelac Subject: Re: mirrored device with thousand of mappingtableentries Date: Mon, 07 Mar 2011 15:24:23 +0100 Message-ID: <4D74EA97.5080209@redhat.com> References: <20110228114801.GZ3626@agk-dp.fab.redhat.com> <20110228121149.GA3626@agk-dp.fab.redhat.com> <20110228131028.GB3626@agk-dp.fab.redhat.com> <4D6BA566.1050305@redhat.com> <4D73F104.2050807@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: dm-devel@redhat.com List-Id: dm-devel.ids Dne 7.3.2011 03:59, Martin K. Petersen napsal(a): >>>>>> "Zdenek" == Zdenek Kabelac writes: > > Zdenek> My finding seems to show that BIP-256 slabtop segment grow by > Zdenek> ~73KB per each device (while dm-io is ab out ~26KB) > > Ok, I see it now that I tried with a bunch of DM devices. > > DM allocates a bioset per volume. And since each bioset has an integrity > mempool you'll end up with a bunch of memory locked down. It seems like > a lot but it's actually the same amount as we reserve for the data path > (bio-0 + biovec-256). > > Since a bioset is not necessarily tied to a single block device we can't > automatically decide whether to allocate the integrity pool or not. In > the DM case, however, we just set up the integrity profile so the > information is available. > > Can you please try the following patch? This will change things so we > only attach an integrity pool to the bioset if the logical volume is > integrity-capable. > Yep - patch seems to fix the problem with wasted memory. Thanks tested-by: zkabelac@redhat.com