Re: [v9.1] sepgsql - userspace access vector cache

2011/6/13 Robert Haas <robertmhaas(at)gmail(dot)com>:
> On Mon, Jun 13, 2011 at 7:51 AM, Kohei KaiGai <kaigai(at)kaigai(dot)gr(dot)jp> wrote:
>> For syscache, length of a typical security label in selinux is
>> less than 64 bytes. If we assume an entry consume 128bytes
>> including Oid pairs or pointers, its consumption is 128KBytes
>> per 1,000 of tables or others.
>> (Do we have a way to confirm syscache status?)
>
> I was thinking you might start a new session, SELECT pg_backendd_pid()
> to get the PID, use top/ps to get its memory usage; then do a bunch of
> stuff and see how much it's grown.  The difference between how much it
> grows with and without the patch is the amount of additional memory
> the patch consumes.
>
I checked memory consumption of the backend with / without
patches. Because sepgsql_restorecon() tries to reset security
label of all the schemas, relations, columns and procedures,
an execution of this function is suitable to emphasize differences
between two cases in maximum.

The results shows us about 3MB of additional consumption
in VmRSS, even if it caches all the security label of the objects
being created in the default (3331 entries).

* without patches before/after sepgsql_restorecon()

VmPeak: 150812 kB -> 170864 kB
VmSize: 150804 kB -> 154712 kB
VmLck: 0 kB -> 0kB
VmHWM: 3800 kB -> 22248 kB
VmRSS: 3800 kB -> 10620 kB
VmData: 1940 kB -> 5820 kB
VmStk: 196 kB -> 196 kB
VmExe: 5324 kB -> 5324 kB
VmLib: 2468 kB -> 2468 kB
VmPTE: 108 kB -> 120 kB
VmSwap: 0 kB -> 0kB

* with patches before/after sepgsql_restorecon()
VmPeak: 150816 kB -> 175092 kB
VmSize: 150808 kB -> 158804 kB
VmLck: 0 kB -> 0 kB
VmHWM: 3868 kB -> 25956 kB
VmRSS: 3868 kB -> 13736 kB
VmData: 1944 kB -> 9912 kB
VmStk: 192 kB -> 192 kB
VmExe: 5324 kB -> 5324 kB
VmLib: 2472 kB -> 2472 kB
VmPTE: 100 kB -> 124 kB
VmSwap: 0 kB -> 0 kB

Thanks,
--
KaiGai Kohei <kaigai(at)kaigai(dot)gr(dot)jp>