> -----Original Message----- > From: Ben Hutchings [mailto:ben@xxxxxxxxxxxxxxx] > Sent: Friday, July 12, 2013 4:17 PM > To: KY Srinivasan > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; > jasowang@xxxxxxxxxx; Stable > Subject: Re: [PATCH 1/2] Drivers: hv: balloon: Fix a bug in the hot-add code > > On Fri, Jul 12, 2013 at 06:56:14AM -0700, K. Y. Srinivasan wrote: > > As we hot-add 128 MB chunks of memory, we wait to ensure that the memory > > is onlined before attempting to hot-add the next chunk. If the udev rule for > > memory hot-add is not executed within the allowed time, we would rollback > the > > state and abort further hot-add. Since the hot-add has succeeded and the only > > failure is that the memory is not onlined within the allowed time, we should not > > be rolling back the state. Fix this bug. > [...] > > /* > > * Wait for the memory block to be onlined. > > */ > > - t = wait_for_completion_timeout(&dm_device.ol_waitevent, > 5*HZ); > > - if (t == 0) { > > - pr_info("hot_add memory timedout\n"); > > - has->ha_end_pfn -= HA_CHUNK; > > - has->covered_end_pfn -= processed_pfn; > > - break; > > - } > > + wait_for_completion_timeout(&dm_device.ol_waitevent, > 5*HZ); > > > > } > > > > Well now it might look like a bug that you don't test the result > of wait_for_completion_timeout(). Maybe update the comment to > explain why it's OK to continue anyway? I put in the comment in the patch explaining why it is ok to continue. To reiterate, it is ok to continue because hot add has succeeded. More importantly, what I was doing earlier - rolling back the state when in fact hot add had succeeded was incorrect. Regards, K. Y > > Ben. > > -- > Ben Hutchings > We get into the habit of living before acquiring the habit of thinking. > - Albert Camus > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
