MySQL Bugs: #29759: Many semaphore waits in SMP

Bug #29759	Many semaphore waits in SMP
Submitted:	12 Jul 2007 14:29	Modified:	27 Nov 2007 14:49
Reporter:	Michail Epikhin	Email Updates:
Status:	Can't repeat	Impact on me:	None
Category:	MySQL Server: InnoDB storage engine	Severity:	S2 (Serious)
Version:	5.0.45	OS:	Windows (2003 Ent R2 x64)
Assigned to:	Inaam Rana	CPU Architecture:	Any
Tags:	SMP, windows, x64, Xeon

Description:
I have Intel Xeon server(SR6850HW4) SL9HB processors with SAS RAID (RAID 10 RAW MYSQL Data, RAID1 MYSQL Logs), 32Gb RAM. Hardware(memory, disks, I/Os) tested - all work fine.
MySQL(I use innodb only) work correctly with my workload if only one processor installed on server, after install second processor server stop query processing (always semaphores wait).

I get this result with x64 binaries from MySQL and my compile binaries using icc 10.0.26

If i set innodb_thread_concurrency=1 server work, but very slow(no semaphore waits).
Sorry my english.

How to repeat:
Start MySQL in SMP server in Win 2k3Ent x64 R2 with more than 4 core, run stresstest: about 50 insert/update/delete in same time.

Innodb monitor

Attachment: im.txt (text/plain), 25.94 KiB.

MySQL configuration

Attachment: config.txt (text/plain), 14.31 KiB.

I have new result: If hyperthreading disabled, server work ok with innodb_thread_concurrency=3 on 4 phisical core.

Michail,

Can you upload the .err file please?
Also have you only noticed long semaphore delays or have these delays caused a crash in some case as well?

regards,
inaam

Server work stable, only long semaphore wait.
I cant upload .err - now I use 5.1.22RC and problem not repetable.
But when I use 5.0.45 no addition info printed in err file (Only Start/Stop).

Michail,

This may be another instance of bug 29560. A fix for that is submitted to 5.0.54. This bug is not present in 5.1.
For now I am setting this to Can't Repeat as you have moved to 5.1. If you have anything to report, please reopen this report.

regards,
inaam