On Tue, Feb 15, 2011 at 01:35:56PM +0000, KY Srinivasan wrote: > > > > -----Original Message----- > > From: Jiri Slaby [mailto:jirislaby@xxxxxxxxx] > > Sent: Tuesday, February 15, 2011 4:21 AM > > To: KY Srinivasan > > Cc: gregkh@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > devel@xxxxxxxxxxxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxx > > Subject: Re: [PATCH 2/3]: Staging: hv: Use native wait primitives > > > > On 02/11/2011 06:59 PM, K. Y. Srinivasan wrote: > > > In preperation for getting rid of the osd layer; change > > > the code to use native wait interfaces. As part of this, > > > fixed the buggy implementation in the osd_wait_primitive > > > where the condition was cleared potentially after the > > > condition was signalled. > > ... > > > @@ -566,7 +567,11 @@ int vmbus_establish_gpadl(struct vmbus_channel > > *channel, void *kbuffer, > > > > > > } > > > } > > > - osd_waitevent_wait(msginfo->waitevent); > > > + wait_event_timeout(msginfo->waitevent, > > > + msginfo->wait_condition, > > > + msecs_to_jiffies(1000)); > > > + BUG_ON(msginfo->wait_condition == 0); > > > > The added BUG_ONs all over the code look scary. These shouldn't be > > BUG_ONs at all. You should maybe warn and bail out, but not kill the > > whole machine. > > This is Linux code running as a guest on a Windows host; and so the guest cannot > tolerate a failure of the host. In the cases where I have chosen to BUG_ON, there > is no reasonable recovery possible when the host is non-functional (as determined > by a non-responsive host). If you have a non-responsive host, wouldn't that imply that this guest code wouldn't run at all? :) Having BUG_ON() in drivers is not a good idea either way. Please remove these in future patches. > > And looking at the code, more appropriate would be completion instead of > > wait events. > > > > And msecs_to_jiffies(1000) == HZ. > > Agreed. In this first round of cleanup, I chose to keep the primitives > as they were in osd.c. Greg, if it is ok with you, I will send you a > patch that fixes these issues on top of the patches I have already > sent. Yes, that is fine. thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
