On Thu, Oct 31, 2019 at 11:12 AM Michael Paquier <mich...@paquier.xyz> wrote: > > On Wed, Oct 30, 2019 at 05:43:04PM +0900, Kyotaro Horiguchi wrote: > > At Wed, 30 Oct 2019 17:21:17 +0900, Fujii Masao <masao.fu...@gmail.com> > > wrote in > >> This change causes every ending backends to always take the exclusive lock > >> even when it's not in SyncRep queue. This may be problematic, for example, > >> when terminating multiple backends at the same time? If yes, > >> it might be better to check SHMQueueIsDetached() again after taking the > >> lock. > >> That is, > > > > I'm not sure how much that harms but double-checked locking > > (releasing) is simple enough for reducing possible congestion here, I > > think. > > FWIW, I could not measure any actual difference with pgbench -C, up to > 500 sessions and an empty input file (just have one meta-command) and > -c 20. > > I have added some comments in SyncRepCleanupAtProcExit(), and adjusted > the patch with the suggestion from Fujii-san. Any comments?
Thanks for the patch! Looks good to me. Regards, -- Fujii Masao
