Bug #79742 No "CPU relax" support for AArch64
Submitted: 22 Dec 2015 13:09 Modified: 3 Oct 2019 12:57
Reporter: Alexey Kopytov (OCA) Email Updates:
Status: No Feedback Impact on me:
None 
Category:MySQL Server: InnoDB storage engine Severity:S5 (Performance)
Version:5.6, 5.7 OS:Any
Assigned to: CPU Architecture:Any

[22 Dec 2015 13:09] Alexey Kopytov 
Description:
Currently busy-wait loops in InnoDB "relax" CPU cores on x86 (with the PAUSE instruction) and POWER with HMT priority instructions.

In the core server there is the LF_BACKOFF macro used for busy waiting in lock free structures. Currently it is only implemented for Windows/MSVC, with GCC/x86, SunStudio/x86 and GCC/POWER support being contributed as a patch for bug #79487.

I'm going to contribute a patch adding support for GCC/AArch64 to the relevant code.

How to repeat:
Inspect code for UT_RELAX_CPU() and LF_BACKOFF.
[3 Sep 2019 12:57] MySQL Verification Team 
Hi Kaamos,

Thank you for your performance improvement report.

Can you, please, be so kind and provide your patch in this bug ????

Thanks in advance.
[4 Oct 2019 1:00] Bugs System 
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
[4 Oct 2019 12:07] MySQL Verification Team 
Kaamos,

Any chance that we get your patch , or even a description of it ????