On 2016-08-22 13:49:47 -0400, Robert Haas wrote: > On Mon, Aug 22, 2016 at 1:46 PM, Andres Freund <and...@anarazel.de> wrote: > > I don't think the runtime overhead is likely to be all that high - if > > you look at valgrind.supp the peformancecritical parts basically are: > > - pgstat_send - the context switching is going to drown out some zeroing > > - xlog insertions - making the crc computation more predictable would > > actually be nice > > - reorderbuffer serialization - zeroing won't be a material part of the > > cost > > > > The rest is mostly bootstrap or python related. > > > > There might be cases where we *don't* unconditionally do the zeroing - > > e.g. I'm doubtful about the sinval stuff where we currently only > > conditionally clear - but the stuff in valgrind.supp seems fine. > > Naturally you'll be wanting to conclusively demonstrate this with > benchmarks on multiple workloads, platforms, and concurrency levels. > Right? :-)
Pah ;) I do think some micro-benchmarks aiming at the individual costs make sense, we're only taking about ~three places in the code - don't think concurrency plays a large role though ;) -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
