Hiro Yoshioka wrote:
Howdy,
MySQL 5.0.26 had some scalability issues and it solved since 5.0.32
http://ossipedia.ipa.go.jp/capacity/EV0612260303/
(written in Japanese but you may read the graph. We compared
5.0.24 vs 5.0.32)
The following is oprofile data
==>
cpu=8-mysql=5.0.32-gcc=3.4/oprofile-eu=2200-op=default-none/opreport-l.txt
<==
CPU: Core Solo / Duo, speed 2666.76 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Unhalted clock cycles) with a unit
mask of 0x00 (Unhalted core cycles) count 100000
samples % app name symbol name
47097502 16.8391 libpthread-2.3.4.so pthread_mutex_trylock
19636300 7.0207 libpthread-2.3.4.so pthread_mutex_unlock
18600010 6.6502 mysqld rec_get_offsets_func
18121328 6.4790 mysqld btr_search_guess_on_hash
11453095 4.0949 mysqld row_search_for_mysql
MySQL tries to get a mutex but it spends about 16.8% of CPU on 8 core
machine.
Curious that it calls pthread_mutex_trylock (as opposed to
pthread_mutex_lock) so often. Maybe they're doing some kind of mutex
lock busy-looping?
--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from [EMAIL PROTECTED]
Home Page: http://www.roberthancock.com/
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