Re: Remove Instruction Synchronization Barrier in spin_delay() for ARM64 architecture - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Remove Instruction Synchronization Barrier in spin_delay() for ARM64 architecture
Date
Msg-id 650064.1755295404@sss.pgh.pa.us
Whole thread Raw
In response to Re: Remove Instruction Synchronization Barrier in spin_delay() for ARM64 architecture  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
Andres Freund <andres@anarazel.de> writes:
> FWIW, I'd not be surprised if moving to atomics would often cause *slowdowns*
> compared to using the spinlocks. You'd replace one atomic operation with
> dozens, to update all those fields individually. With loads of cacheline
> pingpong inbetween.

Not only that, but you'd no longer have any semblance of read-consistency
between the fields of a stats entry.

            regards, tom lane



pgsql-hackers by date:

Previous
From: Nathan Bossart
Date:
Subject: Re: Remove Instruction Synchronization Barrier in spin_delay() for ARM64 architecture
Next
From: Tom Lane
Date:
Subject: Re: Making jsonb_agg() faster