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 > > Additionally it has the advantage that top/ps/... output under linux now looks > like: > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 10603 andres 20 0 6381m 4924 1952 R 21 0.0 0:28.04 postgres > > i.e. RES now actually shows something usable... Which is rather nice imo. > > I don't have the time atm into making this something useable, maybe somebody > else want to pick it up? Looks pretty worthwile investing some time. > > Because of the required setup we sure cannot make this the default but...
... those results are just spectacular (IMO). nice! merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
