On Fri, May 19, 2023 at 12:24 PM Michael Paquier <mich...@paquier.xyz> wrote: > > On Thu, May 18, 2023 at 11:18:25AM +0530, Bharath Rupireddy wrote: > > I think what I have so far seems more verbose explaining what a > > barrier does and all that. I honestly think we don't need to be that > > verbose, thanks to README.barrier. > > Agreed. This file is a mine of information. > > > I simplified those 2 comments as the following: > > > > * NB: pg_atomic_exchange_u64, having full barrier semantics will ensure > > * the variable is updated before releasing the lock. > > > > * NB: pg_atomic_exchange_u64, having full barrier semantics will ensure > > * the variable is updated before waking up waiters. > > > > Please find the attached v7 patch. > > Nit. These sentences seem to be worded a bit weirdly to me. How > about: > "pg_atomic_exchange_u64 has full barrier semantics, ensuring that the > variable is updated before (releasing the lock|waking up waiters)."
I get it. How about the following similar to what
ProcessProcSignalBarrier() has?
+ * Note that pg_atomic_exchange_u64 is a full barrier, so we're guaranteed
+ * that the variable is updated before waking up waiters.
+ */
+ * Note that pg_atomic_exchange_u64 is a full barrier, so we're guaranteed
+ * that the variable is updated before releasing the lock.
*/
Please find the attached v8 patch with the above change.
--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
v8-0001-Optimize-WAL-insertion-lock-acquisition-and-relea.patch
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