Re: locking/performance, Solaris performance discovery

On Mon, 6 Oct 2003, Tom Lane wrote:

>
> Does Solaris have Posix semaphores? You could try using those instead.
>
> regards, tom lane

Yep. It does.

I learned them quick enough (using posix_sema.c as a guide)
and found out that at least on Sol 2.6 they are slower than sysv - with 5
processes it went to about 16k lock/unlock a second.

I'm going to try to find a box around here I can get sol(8|9) on that has
sufficient disk space and see. I'm guessing sun has likely made
improvements...

Another odd thing I'm trying to work out is why my profiles come out so
radically different on the linux box and the sun box.

Sun:
31.17 18.90 18.90 internal_mcount
19.10 30.48 11.58 8075381 0.00 0.00 _bt_checkkeys
5.66 33.91 3.43 24375253 0.00 0.00 FunctionCall2
4.82 36.83 2.92 8073010 0.00 0.00 _bt_step
3.51 38.96 2.13 14198 0.15 0.15 _read
2.77 40.64 1.68 8069040 0.00 0.00 varchareq
2.59 42.21 1.57 28454 0.06 0.23 _bt_next
2.29 43.60 1.39 1003 1.39 1.40 AtEOXact_Buffers
1.86 44.73 1.13 16281197 0.00 0.00 pg_detoast_datum
1.81 45.83 1.10 _mcount
1.68 46.85 1.02 2181 0.47 0.47 pglz_decompress

Linux:
11.14 0.62 0.62 1879 0.00 0.00 pglz_decompress
6.71 0.99 0.37 1004 0.00 0.00 AtEOXact_Buffers
3.80 1.20 0.21 1103045 0.00 0.00 AllocSetAlloc
3.23 1.38 0.18 174871 0.00 0.00 nocachegetattr
2.92 1.54 0.16 1634957 0.00 0.00 AllocSetFreeIndex
2.50 1.68 0.14 20303 0.00 0.00 heapgettup
1.93 1.79 0.11 1003 0.00 0.00 AtEOXact_CatCache
1.76 1.89 0.10 128442 0.00 0.00 hash_any
1.72 1.98 0.10 90312 0.00 0.00 FunctionCall3
1.69 2.08 0.09 50632 0.00 0.00 ExecTargetList
1.60 2.17 0.09 51647 0.00 0.00 heap_formtuple
1.55 2.25 0.09 406162 0.00 0.00 newNode
1.46 2.33 0.08 133044 0.00 0.00 hash_search

It is the same query with slightly different data (The Sun has probably..
20-40k more rows in the table the query hits).

I'll be digging up more info later today.

--
Jeff Trout <jeff(at)jefftrout(dot)com>
http://www.jefftrout.com/
http://www.stuarthamm.net/