On 7 May 2012 18:09, Tom Lane <t...@sss.pgh.pa.us> wrote: > Peter Geoghegan <pe...@2ndquadrant.com> writes: >> This latest revision also covers the checkpointer. The code for that >> is far simpler than that for the WAL Writer, so it doesn't >> particularly feel like I'm pushing my luck by slipping that into >> something to be slipped in. > > Well ... maybe, or maybe not, or maybe you are just poking at a sore > spot that was already created by the patch to make a separate > checkpointer process. What bothers me in looking at this is that the > main loop of the checkpointer includes an AbsorbFsyncRequests() call, > which is now the only wakeup condition that isn't covered by latch > logic or a predictable time delay. A long sleep period could easily > result in overflow of the fsync request queue, which is not good for > performance. I'm inclined to think that we'd better add logic to > ForwardFsyncRequest() to set the latch once the queue is, say, more > than half full.
OK > I also notice that the separate-checkpointer patch failed to rename > assorted things like BgWriterCommLock, BgWriterRequest, > BgWriterShmemStruct, which are all 100% inappropriately named now. > And it still contains various obsolete comments referring to itself > as the background writer. Will see about cleaning that up. For want of a better name, keeping them the same seemed best. If you have a suggested name change, I'd be happy to oblige. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
