On 26/11/15 16:14, David Vrabel wrote: > If more than 1024 event channels are bound to a evtchn device then it > possible (even with well behaved applications) for the ring to > overflow and events to be lost (reported as an -EFBIG error). > > Dynamically increase the size of the ring so there is always enough > space for all bound events. Well behaved applicables that only unmask > events after draining them from the ring can thus no longer lose > events. > > However, an application could unmask an event before draining it, > allowing multiple entries per port to accumulate in the ring, and a > overflow could still occur. So the overflow detection and reporting > is retained. > > The ring size is initially only 64 entries so the common use case of > an application only binding a few events will use less memory than > before. The ring size may grow to 512 KiB (enough for all 2^17 > possible channels). This order 7 kmalloc() may fail due to memory > fragmentation, so we fall back to trying vmalloc(). > > Signed-off-by: David Vrabel <david.vra...@citrix.com>
Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
