Re: Allowing WAL fsync to be done via O_SYNC
Larry Rosenman <ler@lerctr.org>
From: Larry Rosenman <ler@lerctr.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alfred Perlstein <bright@wintelcom.net>, "William K. Volkman" <wkv@hiscorp.net>, pgsql-hackers@postgresql.org
Date: 2001-03-18T22:15:06Z
Lists: pgsql-hackers
* Tom Lane <tgl@sss.pgh.pa.us> [010318 14:55]: > Alfred Perlstein <bright@wintelcom.net> writes: > >> 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. > > It'd be interesting to try to get some numbers about the actual cost > of using a thread-aware libc, on platforms where there's a difference. > Shouldn't be that hard to build a postgres executable with the proper > library and run some benchmarks ... anyone care to try? I can get the code compiled, but don't have the skills to generate a test case worthy of anything.... LER > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 972-414-9812 E-Mail: ler@lerctr.org US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749