Re: [PATCH 0/8] Drop host_lock around LLD SHT->queuecommand()caller

From: Nicholas A. Bellinger
Date: Thu Sep 16 2010 - 21:35:25 EST


On Thu, 2010-09-16 at 18:29 -0700, Tim Chen wrote:
> On Thu, 2010-09-16 at 15:35 -0700, Nicholas A. Bellinger wrote:
> > From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
> >
> > Greetings all,
> >
> > This series contains the first round of a whole-sale conversion for droping
> > struct Scsi_Host->host_lock around struct Scsi_Host->queuecommand() within
> > scsi_dispatch_cmd(). So with this first patch the only part of scsi_dispatch_cmd()
> > that is protected by host_lock is scsi_cmd_get_serial)_.
> >
>
> Maybe we can change the host->cmd_serial_number to atomic and totally
> avoid the need to take host_lock.

Hmmmm good point, then we would also need an atomic_t for signaling
(shost_state == SHOST_DEL) in scsi_dispatch_cmd() to be able to
completly drop host_lock usage within scsi_dispatch_cmd().

I can take a look at doing this specific part, if you would be willing
to have a look at the host->cmd_serial_number conversion piece. ;)

Thanks Tim!

--nab


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