Re: making use of large TLB pages - Mailing list pgsql-hackers

From Neil Conway
Subject Re: making use of large TLB pages
Date
Msg-id 87znu0vn2l.fsf@mailbox.samurai.com
Whole thread Raw
In response to Re: making use of large TLB pages  (Bruce Momjian <pgman@candle.pha.pa.us>)
Responses Re: making use of large TLB pages  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Bruce Momjian <pgman@candle.pha.pa.us> writes:
> OK, personally, I would like to see an actual speedup of PostgreSQL
> queries before I would apply such a OS-specific, version-specific
> patch.

Don't be silly. A performance improvement is a performance
improvement. According to your logic, using assembly-optimized locking
primitives shouldn't be done unless we've exhausted every possible
optimization in every other part of the system (a process which will
likely never be finished).

If the optimization was for some obscure UNIX variant and/or an
obscure processor, I would agree that it wouldn't be worth the
bother. But given that
       (a) Linux on IA32 is likely our most popular platform [1]
       (b) In theory, this will help performance where we need it           most, IMHO (high-end systems using large
sharedbuffers)
 

I think it's at least worth implementing -- if it doesn't provide a
noticeable performance improvement, then we don't need to merge it.

Cheers,

Neil

[1] It's worth noting that the huge tlb patch currently works in IA64,
SPARC, and may well be ported to additional architectures in the
future.

-- 
Neil Conway <neilc@samurai.com> || PGP Key ID: DB3C29FC



pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: pg_config : postgresql.conf adjustments?
Next
From: Tom Lane
Date:
Subject: Re: Do we want a CVS branch now?