From: Sven Geisler <sgeisler@aeccom.com>
To: Luke Lonergan <llonergan@greenplum.com>
Cc: Postgresql Performance <pgsql-performance@postgresql.org>
Subject: Re: 64-bit vs 32-bit performance ... backwards?
Date: Tue, 13 Jun 2006 14:46:51 +0200
Message-ID: <448EB3BB.9030504@aeccom.com> (raw)
In-Reply-To: <C0B400B0.26F9B%llonergan@greenplum.com>
References: <C0B400B0.26F9B%llonergan@greenplum.com>
Luke
Luke Lonergan schrieb:
> Sven,
> On 6/13/06 5:03 AM, "Sven Geisler" <sgeisler@aeccom.com> 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.
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To: pgsql-performance@postgresql.org
Cc: sgeisler@aeccom.com, llonergan@greenplum.com
Subject: Re: 64-bit vs 32-bit performance ... backwards?
In-Reply-To: <448EB3BB.9030504@aeccom.com>
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