Postgres Pro
Downloads
Home   >   mailing lists

Re: WAL Insertion Lock Improvements (was: Re: Avoid LWLockWaitForVar() for currently held WAL insertion lock in WaitXLogInsertionsToFinish()) - Mailing list pgsql-hackers

From Nathan Bossart
Subject Re: WAL Insertion Lock Improvements (was: Re: Avoid LWLockWaitForVar() for currently held WAL insertion lock in WaitXLogInsertionsToFinish())
Date
Msg-id 20221203003158.GA2518778@nathanxps13
Whole thread Raw
In response to WAL Insertion Lock Improvements (was: Re: Avoid LWLockWaitForVar() for currently held WAL insertion lock in WaitXLogInsertionsToFinish())  (Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>)
Responses Re: WAL Insertion Lock Improvements (was: Re: Avoid LWLockWaitForVar() for currently held WAL insertion lock in WaitXLogInsertionsToFinish())  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
Tree view 
On Fri, Dec 02, 2022 at 04:32:38PM +0530, Bharath Rupireddy wrote:
> On Fri, Dec 2, 2022 at 6:10 AM Andres Freund <andres@anarazel.de> wrote:
>> I'm not sure this is quite right - don't we need a memory barrier. But I don't
>> see a reason to not just leave this code as-is. I think this should be
>> optimized entirely in lwlock.c
> 
> Actually, we don't need that at all as LWLockWaitForVar() will return
> immediately if the lock is free. So, I removed it.

I briefly looked at the latest patch set, and I'm curious how this change
avoids introducing memory ordering bugs.  Perhaps I am missing something
obvious.

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com

pgsql-hackers by date:

Previous
From: David Zhang
Date:
Subject: Re: Patch: Global Unique Index
Next
From: Nathan Bossart
Date:
Subject: Re: Generate pg_stat_get_* functions with Macros