> -----Original Message----- > From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx] > Sent: Friday, August 5, 2016 3:49 AM > To: devel@xxxxxxxxxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx; Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; KY > Srinivasan <kys@xxxxxxxxxxxxx>; Alex Ng (LIS) <alexng@xxxxxxxxxxxxx> > Subject: [PATCH 3/4] Drivers: hv: balloon: get rid on ol_waitevent > > With the recently introduced in-kernel memory onlining > (MEMORY_HOTPLUG_DEFAULT_ONLINE) these it no point in waiting for pages > to come online in the driver and in case the feature is disabled the 5 > second wait won't help. Get rid of the waiting. > Continuing our internal discussion here. Here's the context. > > Is it necessary to remove the ol_waitevent in "Drivers: hv: balloon: get rid > > on ol_waitevent"? If we respond to the host too quickly, then the next > > hot-add request may not see the new pages come online and could fail to > > alloc memory as seen in the call trace. > > > > Thoughts? > > This should not be an issue with CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE: we > online pages when we add them (add_memory()) so when we reply to the host > these pages are already online. But in case the onlining is done by an > external tool (e.g. udev) this wait helps (not always, as if someone eats > all memory before the next add_memory call we're still in trouble). MEMORY_HOTPLUG_DEFAULT_ONLINE is disabled in Kconfig by default. Would it make sense to keep the wait and only #ifdef it out when CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE is set? _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
