On Tue, 2013-10-29 at 11:09 -0500, [email protected] wrote: > On Tue, Oct 29, 2013 at 02:43:56PM +0800, Wei Yongjun wrote: > > From: Wei Yongjun <[email protected]> > > > > In case of error, the function kthread_run() returns ERR_PTR() > > and never returns NULL. The NULL test in the return value check > > should be replaced with IS_ERR(). > > > > Signed-off-by: Wei Yongjun <[email protected]> > > --- > > drivers/scsi/hpsa.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c > > index 891c86b..f413b14 100644 > > --- a/drivers/scsi/hpsa.c > > +++ b/drivers/scsi/hpsa.c > > @@ -4757,7 +4757,8 @@ static void start_controller_lockup_detector(struct > > ctlr_info *h) > > kthread_run(detect_controller_lockup_thread, > > NULL, HPSA); > > } > > - if (!hpsa_lockup_detector) { > > + if (IS_ERR(hpsa_lockup_detector)) { > > + hpsa_lockup_detector = NULL; > > dev_warn(&h->pdev->dev, > > "Could not start lockup detector thread\n"); > > return; > > Ack.
Hmm, this whole lockup thread start/stop thing is horribly racy with hotplug (and bind and unbind). Firstly, why do you need an actual thread, why not just use a workqueue? That way you don't need a list or a lock, you can just schedule work for each instance? since they don't interfere, no global list and no lock. If you insist on a thread, it should probably start at module insertion and be shut down at module removal, so no races. You can have it sleep forever on list_empty(&hpsa_ctlr_list) and wake it when you add a controller. James -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
