| Bug #99966 | Switching to use NUMA-SMART Counter for statistical counters | ||
|---|---|---|---|
| Submitted: | 24 Jun 2020 8:12 | Modified: | 30 Jun 2020 2:07 |
| Reporter: | Krunal Bauskar | Email Updates: | |
| Status: | Verified | Impact on me: | |
| Category: | MySQL Server: InnoDB storage engine | Severity: | S5 (Performance) |
| Version: | 8.0.20 | OS: | Any |
| Assigned to: | CPU Architecture: | ARM | |
| Tags: | arm, numa, PowerPC, x86 | ||
[24 Jun 2020 8:13]
Krunal Bauskar
BMS-ARM Pattern-1 benchmarking result
Attachment: bms.arm.pattern1.png (image/png, text), 70.29 KiB.
[24 Jun 2020 8:14]
Krunal Bauskar
VM-x86 Pattern 1 results
Attachment: vm.x86.pattern1.png (image/png, text), 62.27 KiB.
[24 Jun 2020 8:14]
Krunal Bauskar
BMS-ARM pattern2 results
Attachment: bms.arm.pattern2.png (image/png, text), 69.31 KiB.
[24 Jun 2020 8:16]
Krunal Bauskar
I have added 3 benchmarking results 1. BMS-arm-pattern-1 (zipfian) 2. vm-x86-pattern-1 (zipfian) 3. BMS-arm-pattern-2 (uniform) Machine details: BMS: 128 cores, ARM (Kunpeng), with 4 NUMA nodes. 100tables*5m all in memory VM: 24 vCPU, ARM (x86 Xeon(R) Gold 6266C CPU @ 3.00GHz) with 2 NUMA nodes. 64t*1.5m in memory.
[24 Jun 2020 12:10]
MySQL Verification Team
Hi Mr. Bauskar, Thank you for your performance improvement report. I have analysed all of the attachments and I have to agree with you. Verified as reported.
[25 Jun 2020 1:40]
Krunal Bauskar
I see arch was updated to ARM. Please note, the said patch/idea is not ARM specific it is meant to help NUMA which is also found in x86. I even show-cased result for x86. Just that my x86 machine it not that strong as ARM. Can we switch it back to "Any"
[25 Jun 2020 11:49]
MySQL Verification Team
Sure. Done.
[25 Jun 2020 12:23]
Krunal Bauskar
Thanks. I appreciate your quick response.
[30 Jun 2020 2:07]
Krunal Bauskar
Not sure why the CPU-arch was reset to ARM. Unfortunately, happening for 2nd time. I would appreciate it if someone can leave a note while moving things explaining why they feel this bug is ARM specific issue given NUMA has nothing to do with ARM only.
[30 Jun 2020 12:45]
MySQL Verification Team
Hi, The CPU architecture has been changed by our Development, but I am notifying them that this is not ARM-only bug report.
Description: - MySQL recently introduced a Shard Counter based framework. This framework expects the caller to pass the shard-id/slot. - As per my understanding, the framework is based on the idea that by having N shards, contention will reduce. While it could hold true core-affinity is being lost. This will cause a shard to move around depending on which core is trying to update the said page. - This movement, especially on NUMA node, introduces serious performance drop. - Also, on the workload that accesses a limited number of pages, contention arising from page-id use will further affect performance. - Based on the study and experiment patch tend to propose a self-contained ib_atomic_counter_t (on the line of ib_counter_t) that does consider the core-affinity. - Patch has proved to show improvement up to 55% on NUMA enabled machine. How to repeat: * Apply the patch that I will submit below and try. Suggested fix: * Performance fix.