Luke
Luke Lonergan schrieb:
Sven,
On 6/13/06 5:03 AM, "Sven Geisler" <sgeisler@xxxxxxxxxx> wrote:
Yes, I know. We had a problem last year with the performance of the
Opteron. We have started the futex patch to resolve the issue. The futex
patch itself did have no effect, but there was a side effect because the
futex patch did use also another assembler sequence. This make a hole
difference on a Opteron. It turned out that removing the lines
cmpb
jne
lock
was the reason why the Opteron runs faster.
I have created a sequence of larger query with following result on
Opteron 875 and PostgreSQL 8.0.3
orignal 8.0.3 => 289 query/time and 10% cpu usage
patched 8.0.3 => 1022 query/time and 45% cpu usage
This was in 64-bit mode on the Opteron?
This was in 32-bit mode on the Opteron. But the effect was the same in
64-bit mode with PostgreSQL 8.0.3.
You already get this change if you compile PostgreSQL 8.1.x in x86_64
(64-bit mode).
Cheers
Sven.
