Date: Wed, 12 Dec 2001 15:00:39 -0500 From: "Ken Menzel" <kenm@icarz.com> To: "Chynnee" <chynnee@mindspring.com>, "Andrew Tulloch" <andrewt@great4.co.uk> Cc: <stable@FreeBSD.ORG> Subject: Re: SMP and MySQL/threads Message-ID: <021c01c18347$ac0af340$711663cf@icarz.com> References: <077a01c18332$3ffd4190$4c0116ac@ANDREWT> <025c01c18336$649e1980$0701a8c0@desktop>
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Hi Brad and Andrew, Maybe pthread CAN run on different CPU's, but I know that MySQL runs on only one CPU with native BSD threads and mutliple CPU's with Linux threads. I have tested this and currently have problems with running out of CPU occasionally on 1 processor and response times dropping off (single process goes to 99% in top, overall cpu usage stays below 50%, dual CPU machine, responses to other users slow or stopped (different databases in use), could be a bug in MySQL or threads having to do with waiting threads). (BTW to answer the original posters question, I also have been running Linux threads for several months with no problems). I want to run Linux threads on production machines but I am skittish about running anything where I don't fully understand how the module is built. I can get the port to build just fine, but I can't seem to build a working Linux Threaded MySQL outside of the port environment (I like to build from the tar file!). I am not sure this is a topic for -stable, maybe this would be more appropiate for ports. Unless there is a way to make MySQL use native threads better. I understood that having a single process use more than one CPU in FreeBSD threads was a feature coming in 5.0? Is this wrong? See: http://www.bsdtoday.com/2001/June/News508.html If something in MySQL needs to change I am sure they will change it to make it work better. We as the BSD community have to tell them what needs to be done. MySQL is critcal to our business, and it's important to us that it works as well as possible. I am sure other FreeBSD users are in this position as well. Besides, I don't like penguins. Ken ----- Original Message ----- From: "Chynnee" <chynnee@mindspring.com> To: "Andrew Tulloch" <andrewt@great4.co.uk> Cc: <stable@FreeBSD.ORG> Sent: Wednesday, December 12, 2001 12:56 PM Subject: Re: SMP and MySQL/threads > Pthread's threads CAN run on different CPUs if they are giving the right > attributes: > pthread_attr_setscope(&thread_attributes, PTHREAD_SCOPE_SYSTEM); > > then the "thread_attribute" is used when creating the thread. > > mysql seems to use this attribute. > maybe if someone is running it on a SMP box, they could tell us more. > > > (i am all about these thread questions today, but if i am wrong someone > please correct me) > > > brad To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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