> -----Original Message----- > From: Johan Hedberg [mailto:johan.hedberg@xxxxxxxxx] > Sent: Tuesday, November 01, 2011 3:52 PM > To: Ilia, Kolominsky; linux-bluetooth@xxxxxxxxxxxxxxx > Subject: Re: Implementation of name-resolve procedures in mgmtops > > Hi, > > On Tue, Nov 01, 2011, Johan Hedberg wrote: > > > > Each "unknown name" device that user-space tells the kernel about > gets > > > > added to a list and once the currently ongoing inquiry finishes > the > > > > kernel proceeds with trying to resolve the name for each device > in the > > > > list, one at a time. For efficiency, this list should be sorted > by > > > > strongest RSSI first so that devices which are with a higher > likelihood > > > > closer to us get their names resolved first. The kernel will also > wait > > > > a > > > > few seconds (2 sounds like an ok value?) if user space hasn't yet > > > > > > Do we really need to wait here? - if this is to allow human > interaction > > > then 2 sec will be not enough anyway, if this is to allow the ack > for > > > the last ( the assumption is that the user will decide whether to > ack or > > > not on more or less sequential way ) discovered device, then, > > > 2 sec is an overkill, so 1 or even 0.5 I think may be enough. > > > > It's for the later case (e.g. for inquiry results that come right > before > > the inquiry complete event). The question then is, for a system under > > heavy load what is a reasonable expectation to schedule in > bluetoothd, > > let it respond to the event and send the command and then schedule > the > > part of the kernel that handles the command from from bluetoothd. > Maybe > > 1 second is enough, but there really isn't any single right answer > for > > this. > > Actually there are two more context switches involved which probably > introduce the most latency into the whole procedure: each time > bluetoothd gets a device_found event with confirm_name set to 1 it'll > need to access the file-system in /var/lib/bluetooth to check if the > name is stored there. Alright then, to be on the safe, let's do it 2 sec, my idea was to finish the whole process asap. But since io is involved, 2 sec seems to be a reasonable balance. > > Johan Ilia -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
