[lkml]   [2007]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: SMP performance degradation with sysbench
J.A. Magallón wrote:
> On Mon, 26 Feb 2007 23:31:29 -0500, Rik van Riel <> wrote:
>> Hiro Yoshioka wrote:

>>> Another question. When the number of threads exceeds the number of
>>> CPU cores, we may get a lot of idle time. Then a workaround of
>>> MySQL is that do not creat threads which exceeds the number
>>> of CPU cores. Is it right?
>> Not really, that would make it impossible for MySQL to
>> handle more simultaneous database queries than the system
>> has CPUs.
> I don't know myqsl internals, but you assume one thread per query.
> If its more like Apache, one long living thread for several connections ?

Yes, they are longer lived client connections. One thread
per connection, just like Apache.

> Its the same to answer 4+4 queries than 8 at half the speed, isn't it ?

That still doesn't fix the potential Linux problem that this
benchmark identified.

To clarify: I don't care as much about MySQL performance as
I care about identifying and fixing this potential bug in

Politics is the struggle between those who want to make their country
the best in the world, and those who believe it already is. Each group
calls the other unpatriotic.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-02-27 15:05    [W:0.064 / U:1.172 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site