Details
-
Bug
-
Status: Closed (View Workflow)
-
Major
-
Resolution: Fixed
-
10.5, 10.6, 10.2(EOL), 10.3(EOL), 10.4(EOL)
Description
On startup, InnoDB tries to prioritize the page cleaner thread. This usually fails, resulting in a log message like the following:
Apr 15 03:28:17 ubuntu-focal-amd64 mariadbd[4875]: 2021-04-15 3:28:17 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
|
A search for that message in this bug reporting system reveals many community user bugs. So, it seems that this code is almost never effective and can be removed:
#ifdef UNIV_LINUX
|
/* linux might be able to set different setting for each thread. |
worth to try to set high priority for the page cleaner thread */
|
const pid_t tid= static_cast<pid_t>(syscall(SYS_gettid)); |
setpriority(PRIO_PROCESS, tid, -20);
|
if (getpriority(PRIO_PROCESS, tid) != -20) |
ib::info() << "If the mysqld execution user is authorized," |
" page cleaner thread priority can be changed." |
" See the man page of setpriority()."; |
#endif /* UNIV_LINUX */ |
When this code was heavily refactored in MDEV-23855, the throughput and latency were greatly improved even when the buf_flush_page_cleaner thread always ran the same priority with other threads in our benchmarks.
So, this code should have no benefit in MariaDB Server 10.5.7 or later.
Attachments
Issue Links
- relates to
-
MDEV-23855 InnoDB log checkpointing causes regression for write-heavy OLTP
- Closed