Re: [PATCH] SCSI: implement scsi_eh_schedule()

[Jeff Garzik <jgarzik@pobox.com>]

Tejun Heo wrote:
> [PATCH] SCSI: implement scsi_eh_schedule()
> 
> This patch implements scsi_eh_schedule() which provides a way to
> directly invoke SCSI EH from drivers which implement EH using
> ->eh_strategy_handler.  Combined with scsi_eh_flush_done_q(), this
> gives such drivers complete control over when and how to invoke EH and
> handle failed commands.
> 
> scsi_eh_schedule() can also be invoked without a scmd.  This is useful
> for handling exception conditions occurring while no command is in
> progress.  New Scsi_Host field host_eh_invoked is added for this.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>

Not so sure about this one:

1) Rather than creating the scmd==NULL special case path, just create a 
new function scsi_kick_eh() or somesuch.  I presume such an 
implementation would be quite tiny:  satisfy the condition 
'shost->host_busy == shost->host_failed', then call scsi_eh_wakeup().

2) Looks almost exactly like scsi_eh_scmd_add().  Minus the code deleted 
via suggestion #1, you really just add a timer check.  Why not add a 
SCSI EH flag which says "check timer", then just call scsi_eh_scmd_add()?

3) I would think that host_eh_invoked could be deduced.

	Jeff