On Tue, Feb 4, 2014 at 12:58:49AM +0100, Andres Freund wrote: > On 2014-02-03 11:22:45 -0500, Tom Lane wrote: > > Andres Freund <and...@2ndquadrant.com> writes: > > > On larger, multi-socket, machines, startup takes a fair bit of time. As > > > I was profiling anyway I looked into it and noticed that just about all > > > of it is spent in LWLockAssign() called by InitBufferPool(). Starting > > > with shared_buffers=48GB on the server Nate Boley provided, takes about > > > 12 seconds. Nearly all of it spent taking the ShmemLock spinlock. > > > Simply modifying LWLockAssign() to not take the spinlock when > > > !IsUnderPostmaster speeds it up to 2 seconds. While certainly not making > > > LWLockAssign() prettier it seems enough of a speedup to be worthwile > > > nonetheless. > > > > Hm. This patch only works if the postmaster itself never assigns any > > LWLocks except during startup. That's *probably* all right, but it > > seems a bit scary. Is there any cheap way to make the logic actually > > be what your comment claims, namely "Interlocking is not necessary during > > postmaster startup"? I guess we could invent a ShmemInitInProgress global > > flag ... > > So, here's a flag implementing things with that flag. I kept your name, > as it's more in line with ipci.c's naming, but it looks kinda odd > besides proc_exit_inprogress.
Uh, where are we on this? -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
