On Mon, Aug 22, 2016 at 1:46 PM, Andres Freund <andres@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? :-)
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
