> -----Original Message----- > From: Dave Hansen [mailto:dave@xxxxxxxx] > Sent: Wednesday, July 24, 2013 5:04 PM > To: KY Srinivasan > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; > andi@xxxxxxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx; linux-mm@xxxxxxxxx; > kamezawa.hiroyuki@xxxxxxxxx; mhocko@xxxxxxx; hannes@xxxxxxxxxxx; > yinghan@xxxxxxxxxx > Subject: Re: [PATCH 2/2] Drivers: hv: balloon: Online the hot-added memory "in > context" > > On 07/24/2013 02:29 PM, K. Y. Srinivasan wrote: > > /* > > - * Wait for the memory block to be onlined. > > - * Since the hot add has succeeded, it is ok to > > - * proceed even if the pages in the hot added region > > - * have not been "onlined" within the allowed time. > > + * Before proceeding to hot add the next segment, > > + * online the segment that has been hot added. > > */ > > - wait_for_completion_timeout(&dm_device.ol_waitevent, > 5*HZ); > > + online_memory_block(start_pfn); > > Ahhhhh.... You've got a timeout in the code in order to tell the > hypervisor that you were successfully able to add the memory? The > userspace addition code probably wasn't running within this timeout > period. right? As I have always said, the onlining would not occur within a specified amount of time (under some conditions). The timeout here is to ensure that we are able to online the memory before attempting to hot-add more memory. With the ability to online memory from within the kernel, we don't need this timeout and the code is much more predictable. Regards, K. Y -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href