On Oct 1, 2010, at 2:14 PM, J. Bruce Fields wrote: > On Fri, Oct 01, 2010 at 11:00:04AM -0700, Marc Eshel wrote: >> On 10/1/2010 10:10 AM, J. Bruce Fields wrote: >>> On Fri, Oct 01, 2010 at 08:40:36AM -0700, Marc Eshel wrote: >>>> On 10/1/2010 5:33 AM, Benny Halevy wrote: >>>>> On 2010-10-01 10:47, Boaz Harrosh wrote: >>>>>> On 10/01/2010 08:12 AM, Tigran Mkrtchyan wrote: >>>>>>> On 10/01/2010 06:17 AM, Marc Eshel wrote: >>>>>>>> Hi Benny, >>>>>>>> >>>>>>>> Running connectathon I see that some times the clients decides to destroy >>>>>>>> the session with the DS. The test continue and the session is >>>>>>>> re-established. It looks like layout return reduces the hold on device >>>>>>>> info the reduces the hold on the client struct which decide to destroy the >>>>>>>> session. Is that a known problem? >>>>>>>> >>>>>> Yes, I want to emphasize on Marks words: "a known *problem*" >>>>> Marc, assuming the code behaves as expected, does this cause any other badness >>>>> like the GETATTRs you see going out to the DS? >>>>> >>>>> Benny >>>>> >>>> No i don't see any "badness" the test continues without errors and >>>> this problem is not related to the GETATTRs I see on the DS but I >>>> would consider destroying the session in short run of couple of >>>> minutes some times more than one time as something bad. >>> Why? >>> >>> I wouldn't expect session destruction/creation to be *that* expensive. >> >> I assumed that it is inexpensive. We are talking about potential >> destruction/creation of session from every DS for each file IO if >> there is no overlap in holding layouts, right ? > > Well, I guess the tradeoffs aren't obvious to me: if you end up having > to set up an enormous number of sessions (and tcp connections, etc.) all > at once, then I can see why it might be a problem. It would also seem > inefficient to keep around an enormous number of those when they aren't > being used for a while. The plan is to add some code that waits a lease time before destroying an un-referenced deviceid. The next submission patch set will include layoutreturn and the return-on-close code, so it will probably be added then. -->Andy > > --b. > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
