Re: [PATCH] qla2xxx: Fix possible race that could hang kthread_stop()

[Bandan Das <bandan.das@stratus.com>]

On  0, Madhu Iyengar <madhu.iyengar@qlogic.com> wrote:
> We at QLogic are fine with James's fix. Here's my ack:
> 
> Acked-by: Madhuranath Iyengar <Madhu.Iyengar@qlogic.com>
> 
> Cheers,
> Madhu
James, You are gonna take care of this or do you want me to send 
a new patch ? I am fine either ways.

 
> -----Original Message-----
> From: linux-scsi-owner@vger.kernel.org [mailto:linux-scsi-owner@vger.kernel.org] On Behalf Of Bandan Das
> Sent: Thursday, January 27, 2011 1:33 PM
> To: James Bottomley
> Cc: Andrew Vasquez; linux-scsi@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH] qla2xxx: Fix possible race that could hang kthread_stop()
> 
> 
> > That's not really the accepted way to fix these race conditions because
> > of the double check of kthread_should_stop(); this is
> > James
> >
> > ---
> > diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
> > index c194c23..15ce69e 100644
> > --- a/drivers/scsi/qla2xxx/qla_os.c
> > +++ b/drivers/scsi/qla2xxx/qla_os.c
> > @@ -3282,10 +3282,10 @@ qla2x00_do_dpc(void *data)
> >
> >       set_user_nice(current, -20);
> >
> > +     set_current_state(TASK_INTERRUPTIBLE);
> >       while (!kthread_should_stop()) {
> >               DEBUG3(printk("qla2x00: DPC handler sleeping\n"));
> >
> > -             set_current_state(TASK_INTERRUPTIBLE);
> >               schedule();
> >               __set_current_state(TASK_RUNNING);
> >
> > @@ -3454,7 +3454,9 @@ qla2x00_do_dpc(void *data)
> >               qla2x00_do_dpc_all_vps(base_vha);
> >
> >               ha->dpc_active = 0;
> > +             set_current_state(TASK_INTERRUPTIBLE);
> >       } /* End of while(1) */
> > +     __set_current_state(TASK_RUNNING);
> >
> >       DEBUG(printk("scsi(%ld): DPC handler exiting\n", base_vha->host_no));
> >
> Yes, this looks more clean and will take care of the problem I am hitting.
> 
> 
> Bandan
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