Hi Sergei, On Wed, Dec 11, 2013 at 09:34:02PM +0100, Sergei Golubchik wrote: > Hi, Sergey! > > On Dec 11, Sergey Vojtovich wrote: > > On Tue, Dec 10, 2013 at 10:14:32PM +0100, Sergei Golubchik wrote: > > > Hi, Sergey! > > > > > > Did you benchmark the improvement you get with this patch? > > Yes, my results against recent 10.0 are in jira task description. > > Ah, I see, thanks. Great! > > > Also please find Axel's results (MDEV-4956 + MDEV-5388) attached. > > From Axel's results please note performance regression between 10.0.4 > > and 10.0.5. > > Why is that, do you know? Not yet, but I plan to investigate it next week.
> > > > Okay, so you only purge one table at time? Since purge is kind of an > > > expensive operation, it's better to amortize the cost of it by > > > purging many tables at once. > > With current algorithm it is impossible to get multiple tables for > > purge here, explanation above. > > But you said that in the next patch it becomes possible, or did I > misunderstand? Yes, it becomes possible, but I'd say it is headache of the next patch. It becomes possible when two (or more) tc_add_table() executed concurrently: thr1: tc_count++ thr2: tc_count++ // Now we will try to evict 2 tables. thr1: <LOCK_open>start expensive eviction</LOCK_open> thr2: <LOCK_open>start expensive eviction</LOCK_open> But for now it is like: thr1: <LOCK_open>tc_count++; start expensive eviction</LOCK_open> thr2: <LOCK_open>tc_count++; start expensive eviction</LOCK_open> Regards, Sergey _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
