Re: Allowing WAL fsync to be done via O_SYNC
Bruce Momjian <pgman@candle.pha.pa.us>
From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Alfred Perlstein <bright@wintelcom.net>
Cc: "William K. Volkman" <wkv@hiscorp.net>, pgsql-hackers@postgresql.org
Date: 2001-03-19T14:29:01Z
Lists: pgsql-hackers
> * William K. Volkman <wkv@hiscorp.net> [010318 11:56] wrote: > > The Hermit Hacker wrote: > > >> > > > But, with shared libraries, are you really pulling in a "whole > > > thread-support library"? My understanding of shared libraries (altho it > > > may be totally off) was that instead of pulling in a whole library, you > > > pulled in the bits that you needed, pretty much as you needed them ... > > > > Just by making a thread call libc changes personality to use thread > > safe routines (I.E. add mutex locking). Use one thread feature, get > > the whole set...which may not be that bad. > > Actually it can be pretty bad. Locked bus cycles needed for mutex > operations are very, very expensive, not something you want to do > unless you really really need to do it. And don't forget buggy implementations. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026