Re: Re[4]: Allowing WAL fsync to be done via O_SYNC
Larry Rosenman <ler@lerctr.org>
From: Larry Rosenman <ler@lerctr.org>
To: The Hermit Hacker <scrappy@hub.org>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Alfred Perlstein <bright@wintelcom.net>, Xu Yifeng <jamexu@telekbird.com.cn>, "Mikheev, Vadim" <vmikheev@SECTORBASE.COM>, Bruce Momjian <pgman@candle.pha.pa.us>, Peter Eisentraut <peter_e@gmx.net>, <pgsql-hackers@postgresql.org>
Date: 2001-03-16T17:23:48Z
Lists: pgsql-hackers
Yes, you are. On UnixWare, you need to add -Kthread, which CHANGES a LOT of primitives to go through threads wrappers and scheduling. See the doc on the http://UW7DOC.SCO.COM or http://www.lerctr.org:457/ web pages. Also, some functions are NOT available without the -Kthread or -Kpthread directives. LER >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<< On 3/16/01, 11:10:34 AM, The Hermit Hacker <scrappy@hub.org> wrote regarding Re: Re[4]: [HACKERS] Allowing WAL fsync to be done via O_SYNC : > On Fri, 16 Mar 2001, Tom Lane wrote: > > Alfred Perlstein <bright@wintelcom.net> writes: > > >> definitely need before considering this is to replace the existing > > >> spinlock mechanism with something more efficient. > > > > > What sort of problems are you seeing with the spinlock code? > > > > It's great as long as you never block, but it sucks for making things > > wait, because the wait interval will be some multiple of 10 msec rather > > than just the time till the lock comes free. > > > > We've speculated about using Posix semaphores instead, on platforms > > where those are available. I think Bruce was concerned about the > > possible overhead of pulling in a whole thread-support library just to > > get semaphores, however. > 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 ... > ---------------------------(end of broadcast)--------------------------- > TIP 2: you can get off all lists at once with the unregister command > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)