Messages in this thread | | | Date | Mon, 25 May 2009 09:46:47 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH 03/13] scsi: unify allocation of scsi command and sense buffer |
| |
On Mon, May 25 2009, Christoph Hellwig wrote: > On Mon, May 25, 2009 at 09:30:48AM +0200, Jens Axboe wrote: > > Fold the sense buffer into the command, thereby eliminating a slab > > allocation and free per command. > > Might help to send it to linux-scsi to get people to review and apply it > :)
yeah, as I later posted, this wasn't meant to be sent out as part of the writeback series :-)
> But that patch looks good to me, avoiding one allocation for each > command and simplifying the code. I try to remember why these were > two slabs to start with but can't find any reason. > > Btw, we might just want to declare the sense buffer directly as a sized > array in the scsi command as there really doesn't seem to be a reason > not to allocate it.
That is also a workable solution. I've been trying to cut down on the number of allocations required per-IO, and there's definitely still some low hanging fruit there. Some of it is already included, like the inline io_vecs in the bio.
-- Jens Axboe
| |