svn commit: r217828 - projects/graid/head/sys/geom/raid

[Pawel Jakub Dawidek]

On Tue, Jan 25, 2011 at 06:33:03PM +0200, Alexander Motin wrote:
> On 25.01.2011 18:17, John Baldwin wrote:
> >Hmm, so this allocates bio's to make the dump work.  I believer other dump
> >routines in other drivers do not do this, but instead use pre-allocated
> >commands to schedule dump I/O requests.  Would it be possible to 
> >pre-allocate
> >the bio that is used here when dumping is enabled and reuse it for each
> >g_raid_dump() call without free'ing it when the I/O is finished?
> 
> Actually I've also thought about it. It is trivial to use static 
> variable in this particular place. But transformation modules 
> (RAID0/RAID1/...) are also allocating some BIOs via g_clone_bio() and 
> there it can be more difficult to fix, as several BIOs are allocated 
> same time to fulfill original request.

I don't think you will ever need more BIOs than you have consumers.
If so, then you could allocate bio per consumer at consumer creation
time and keep it somewhere in g_consumer->private.

-- 
Pawel Jakub Dawidek                       http://www.wheelsystems.com
pjd at FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!
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