From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Qingqing Zhou <zhouqq(at)cs(dot)toronto(dot)edu> |
Cc: | pgsql-patches(at)postgresql(dot)org |
Subject: | Re: Change BgWriterCommLock to spinlock |
Date: | 2006-01-08 23:22:22 |
Message-ID: | 24000.1136762542@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-patches |
Qingqing Zhou <zhouqq(at)cs(dot)toronto(dot)edu> writes:
> On Sun, 8 Jan 2006, Tom Lane wrote:
>> Why is this a good idea?
> "In spirit of incremental improvement":
> (1) The spinlock itself are light weight than the LWLock here and we can
> reduce the lock contention a little bit in AbsorbFsyncRequests();
Spinlock-based coding is inherently much more fragile than LWLock-based
coding. I'm against changing things in that direction unless a
substantial performance improvement can be gained. You didn't offer
any evidence of improvement at all.
> (2) Don't need the CRITICAL SECTION in AbsorbFsyncRequests() any more;
Really? I think this coding still breaks, rather badly, if
RememberFsyncRequest fails. Certainly the reasons for needing a
critical section have nothing to do with what kind of lock is used.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Qingqing Zhou | 2006-01-08 23:32:49 | Re: Change BgWriterCommLock to spinlock |
Previous Message | Qingqing Zhou | 2006-01-08 22:57:51 | Re: Change BgWriterCommLock to spinlock |