[MDEV-23633] MY_RELAX_CPU performs unnecessary compare-and-swap on ARM - Jira

XML

Word

Printable

Details

Type: Bug
Status: Closed (View Workflow)
Priority: Major
Resolution: Fixed
Affects Version/s: 10.2(EOL), 10.3(EOL), 10.4(EOL), 10.5(EOL)
Fix Version/s: 10.4.16, 10.5.7
Component/s: Storage Engine - InnoDB
Labels:
- ARM
- ARMv8
- performance
Environment:
ARMv8

Description

This is basically a re-request to fix ~~MDEV-14374~~ as it was described. On target architectures where nothing special is available (not IA-32, AMD64, POWER), the macro UT_RELAX_CPU() would perform a dummy compare-and-swap operation.

According to krunalbauskar, this extra operation is visible in some benchmarks.

Attachments

- Sort By Name
- Sort By Date
- Ascending
- Descending
- Thumbnails
- List
- Download All

MDB-10.4.14-ARM-testing.png
60 kB
2020-09-04 07:17

Issue Links

blocks

MDEV-23635 Add notional delay (using existing ut_delay) while spinning for registering reader in rw-locks

Open

relates to

MDEV-14374 UT_DELAY code : Removing hardware barrier for arm64 bit platform

Closed

MDEV-24630 MY_RELAX_CPU assembly instruction upgrade/research for memory barrier on ARM

Closed

Activity

People

Assignee:: Marko Mäkelä

Reporter:: Marko Mäkelä

Votes:: 0 Vote for this issue

Watchers:: 2 Start watching this issue

Dates

Created:: 2020-08-31 14:28

Updated:: 2021-01-20 06:32

Resolved:: 2020-09-04 07:47

Time Tracking

Estimated:

Remaining:

Logged:

1.5h

Git Integration

Error rendering 'com.xiplink.jira.git.jira_git_plugin:git-issue-webpanel'. Please contact your Jira administrators.