[PATCH 0/2] delay initializing queue for request-based dm

[PATCH 0/2] delay initializing queue for request-based dm

[Nikanth Karthikesan]

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

[PATCH-v2 0/2] delay initializing queue for request-based dm

[Nikanth Karthikesan]

On Saturday 08 August 2009 10:25:53 Nikanth Karthikesan wrote:
> 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.
>

Changes since v1:
1. Refreshed on top of a4e7d46407d73f35d217013b363b79a8f8eafcaa
2. Added comments suggested by Mike Snitzer.
3. Cleaned up the second patch as suggested by Mike Snitzer.

Thanks
Nikanth

[PATCH-v3 0/2] delay initializing queue for request-based dm

[Nikanth Karthikesan]

On Monday 10 August 2009 16:18:12 Nikanth Karthikesan wrote:
> On Saturday 08 August 2009 10:25:53 Nikanth Karthikesan wrote:
> > 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.
>
> Changes since v1:
> 1. Refreshed on top of a4e7d46407d73f35d217013b363b79a8f8eafcaa
> 2. Added comments suggested by Mike Snitzer.
> 3. Cleaned up the second patch as suggested by Mike Snitzer.
>

Changes since v2:
1. Add comments suggested by Kiyoshi Ueda
2. Export symbol elv_register_queue() to modules.
3. Call elv_register_queue() after initializing the queue to use the elevator.

Thanks
Nikanth