On Fri, Jun 29, 2012 at 04:03:40PM -0700, Daniel Farina wrote: > On Fri, Jun 29, 2012 at 1:00 PM, Merlin Moncure <mmonc...@gmail.com> wrote: > > On Fri, Jun 29, 2012 at 2:52 PM, Andres Freund <and...@2ndquadrant.com> > > wrote: > >> Hi All, > >> > >> In a *very* quick patch I tested using huge pages/MAP_HUGETLB for the > >> mmap'ed > >> memory. > >> That gives around 9.5% performance benefit in a read-only pgbench run (-n > >> -S - > >> j 64 -c 64 -T 10 -M prepared, scale 200, 6GB s_b, 8 cores, 24GB mem). > >> > >> It also saves a bunch of memory per process due to the smaller page table > >> (shared_buffers 6GB): > >> cat /proc/$pid_of_pg_backend/status |grep VmPTE > >> VmPTE: 6252 kB > >> vs > >> VmPTE: 60 kB > > ... those results are just spectacular (IMO). nice! > > That is super awesome. Smallish databases with a high number of > connections actually spend a considerable fraction of their > otherwise-available-for-buffer-cache space on page tables in common > cases currently.
I thought newer Linux kernels did huge pages automatically? What Linux kernel is this? -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
