Messages in this thread | | | Date | Tue, 27 Feb 2007 09:32:09 +0900 | From | "Hiro Yoshioka" <> | Subject | Re: SMP performance degradation with sysbench |
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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.
I think there are a lot of room to be inproved in MySQL implementation.
On 2/27/07, Dave Jones <davej@redhat.com> wrote: > On Mon, Feb 26, 2007 at 04:04:01PM -0600, Pete Harlan wrote: > > On Tue, Feb 27, 2007 at 12:36:04AM +1100, Nick Piggin wrote: > > > I found a couple of interesting issues so far. Firstly, the MySQL > > > version that I'm using (5.0.26-Max) is making lots of calls to > > > > FYI, MySQL fixed some scalability problems in version 5.0.30, as > > mentioned here: > > > > http://www.mysqlperformanceblog.com/2007/01/03/innodb-benchmarks/ > > > > It may be worth using more recent sources than 5.0.26 if tracking down > > scaling problems in MySQL. > > The blog post that originated this discussion ran tests on 5.0.33 > Not that the mysql version should really matter. The key point here > is that FreeBSD and Linux were running the *same* version, and > FreeBSD was able to handle the situation better somehow. > > Dave > > -- > http://www.codemonkey.org.uk > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
Regards, Hiro -- Hiro Yoshioka mailto:hyoshiok at miraclelinux.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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