From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nikanth Karthikesan <knikanth@suse.de>
Subject: [PATCH 0/2] delay initializing queue for request-based dm
Date: Sat, 8 Aug 2009 10:25:53 +0530
Message-ID: <200908081025.54154.knikanth@suse.de>
Reply-To: device-mapper development <dm-devel@redhat.com>
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To: Jens Axboe <jens.axboe@oracle.com>, Alasdair G Kergon <agk@redhat.com>
Cc: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>, dm-devel@redhat.com, linux-kernel@vger.kernel.org
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Hi

Currently for device-mapper devices, we initialize the mempool for requests 
and elevator at device creation time. But only request-based devices use the 
elevator and mempool. These patches change it to allocate the mempool and 
initialize the elevator only for request-based devices. This is done by 
allocating a queue at device creation time, but delaying the initialization of 
elevator and allocation of mempool till the first table load time, when the 
type of device would be known.

[PATCH 1/2] Allow delaying initialization of queue after allocation

[PATCH 2/2] Initialize mempool and elevator only for request-based dm devices

Another approach would be to free the mempool and detach elevator, if it would 
be a bio-based device. But it is better to avoid initialization itself.

Thanks
Nikanth