I'm booting the default kernel on a dual quad core Xeon machine. I only see four CPUs and I expect to see 8.
Do I have to build a custom kernel?
Is there a switch or configuration parameter I need to set?
Thanks,
Jerry
On Mon, 2007-02-26 at 08:09 -0500, Jerry Muller wrote:
I'm booting the default kernel on a dual quad core Xeon machine. I only see four CPUs and I expect to see 8.
Do I have to build a custom kernel?
Is there a switch or configuration parameter I need to set?
Thanks,
Jerry
OK ... is it a:
Quad Processor (4 physical processors) Dual Core Xeon ...
or
Dual Processor (2 physical processors) Quad Core Xeon ...
I have never heard if a "Quad Core" processor in production ... it might be there, I could have missed it.
On Mon, 26 Feb 2007 at 7:40am, Johnny Hughes wrote
OK ... is it a:
Quad Processor (4 physical processors) Dual Core Xeon ...
or
Dual Processor (2 physical processors) Quad Core Xeon ...
I have never heard if a "Quad Core" processor in production ... it might be there, I could have missed it.
E.g.:
http://www.siliconmechanics.com/i8665/Quad-Core-Xeon.php
In the CPU pull down menu you'll see both dual core and quad core Xeons.
On Mon, 2007-02-26 at 08:44 -0500, Joshua Baker-LePain wrote:
On Mon, 26 Feb 2007 at 7:40am, Johnny Hughes wrote
OK ... is it a:
Quad Processor (4 physical processors) Dual Core Xeon ...
or
Dual Processor (2 physical processors) Quad Core Xeon ...
I have never heard if a "Quad Core" processor in production ... it might be there, I could have missed it.
E.g.:
http://www.siliconmechanics.com/i8665/Quad-Core-Xeon.php
In the CPU pull down menu you'll see both dual core and quad core Xeons.
Someone what to send me some of those so I can test kernel modules on them :P
On Mon, 26 Feb 2007 at 7:55am, Johnny Hughes wrote
On Mon, 2007-02-26 at 08:44 -0500, Joshua Baker-LePain wrote:
On Mon, 26 Feb 2007 at 7:40am, Johnny Hughes wrote
OK ... is it a:
Quad Processor (4 physical processors) Dual Core Xeon ...
or
Dual Processor (2 physical processors) Quad Core Xeon ...
I have never heard if a "Quad Core" processor in production ... it might be there, I could have missed it.
E.g.:
http://www.siliconmechanics.com/i8665/Quad-Core-Xeon.php
In the CPU pull down menu you'll see both dual core and quad core Xeons.
Someone what to send me some of those so I can test kernel modules on them :P
Heh. Be careful what you wish for. Keep in mind those 8 cores *still* share a single memory controller. In my testing, my Xeon 5160s are a *lot* better than the old P4 based Xeons at memory intensive code (i.e. they show contention less readily). But I do have some code that brings them to their knees when run across all 4 cores in a system (whereas dual core Opterons continue merrily along). Running said code across 8 cores with one path to memory would be painful.
Things ought to get *real* interesting when AMD's quad cores come out...
On Mon, Feb 26, 2007 at 07:55:32AM -0600, Johnny Hughes wrote:
Someone what to send me some of those so I can test kernel modules on them :P
Yes master ;)
[tru@quadcore ~]$ uname -a Linux quadcore 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 x86_64 x86_64 x86_64 GNU/Linux [tru@quadcore ~]$ grep -A4 processor /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU X5355 @ 2.66GHz -- processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU X5355 @ 2.66GHz -- processor : 2 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU X5355 @ 2.66GHz -- processor : 3 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU X5355 @ 2.66GHz -- processor : 4 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU X5355 @ 2.66GHz -- processor : 5 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU X5355 @ 2.66GHz -- processor : 6 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU X5355 @ 2.66GHz -- processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU X5355 @ 2.66GHz
;)
I see something similar in /proc/cpuinfo but the system monitor only shows 4 CPUs.
----- Original Message ----- From: "Tru Huynh" tru@centos.org To: "CentOS mailing list" centos@centos.org Sent: Monday, February 26, 2007 9:04 AM Subject: Re: [CentOS] CentOS 4.4 smp on Dual Quad Core Xeon
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Yup, they're all there. I guess the problem is with System Monitor (graphical....)
Thanks,
Jerry
----- Original Message ----- From: "Johnny Hughes" mailing-lists@hughesjr.com To: "CentOS ML" centos@centos.org Sent: Monday, February 26, 2007 11:01 AM Subject: Re: [CentOS] CentOS 4.4 smp on Dual Quad Core Xeon
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Jerry Muller wrote:
Yup, they're all there. I guess the problem is with System Monitor (graphical....)
Thanks,
This behaviour of "top" also confused me, at first. After buying our first shiny new dual dual-core opteron box, I noted only one cpu when I ran top. So I figured "gosh, I guess it's not running an SMP kernel" and checked /var/log/messages to see how many cpus appeared on boot. All 4 cores were detected and it showed that it loaded the smp kernel. That's when I dug into the man page for top and found the "1" key. :)
Cheers,
On Mon, Feb 26, 2007 at 10:49:02AM -0500, Jerry Muller wrote:
I see something similar in /proc/cpuinfo but the system monitor only shows 4 CPUs.
show us some details if you want some help...
motherboard/cpu type/make model, dmidecode/lspci/dmesg,... cat /proc/cpuinfo, anything.
Otherwise, I can only say it works for me out of the box.
On Mon, 2007-02-26 at 08:09 -0500, Jerry Muller wrote: Do I have to build a custom kernel?
no
Is there a switch or configuration parameter I need to set?
no
Tru PS: my crystal ball is not working from here, send me your hardware I will have a closer look ;)
Tru Huynh wrote:
[tru@quadcore ~]$ uname -a Linux quadcore 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 x86_64 x86_64 x86_64 GNU/Linux [tru@quadcore ~]$ grep -A4 processor /proc/cpuinfo processor : 0
Just take care with more than 8 CPUs, because you need the largesmp kernel then. Worked on a 8 socket, 16 CPU system where that was a pain due to binary kernel modules.
Now those machines could be 32 CPU systems... and you could add 8 sockets more. 64 CPUs on Intel platform with commodity hardware. Not that many years ago that would have been utopia :)
Morten Torstensen wrote:
Tru Huynh wrote:
[tru@quadcore ~]$ uname -a Linux quadcore 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 x86_64 x86_64 x86_64 GNU/Linux [tru@quadcore ~]$ grep -A4 processor /proc/cpuinfo processor : 0
Just take care with more than 8 CPUs, because you need the largesmp kernel then. Worked on a 8 socket, 16 CPU system where that was a pain due to binary kernel modules.
Now those machines could be 32 CPU systems... and you could add 8 sockets more. 64 CPUs on Intel platform with commodity hardware. Not that many years ago that would have been utopia :)
A few years from now you'll need that much horsepower to play Quake VIII. :)
chrism@imntv.com spake the following on 2/26/2007 8:51 AM:
Morten Torstensen wrote:
Tru Huynh wrote:
[tru@quadcore ~]$ uname -a Linux quadcore 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 x86_64 x86_64 x86_64 GNU/Linux [tru@quadcore ~]$ grep -A4 processor /proc/cpuinfo processor : 0
Just take care with more than 8 CPUs, because you need the largesmp kernel then. Worked on a 8 socket, 16 CPU system where that was a pain due to binary kernel modules.
Now those machines could be 32 CPU systems... and you could add 8 sockets more. 64 CPUs on Intel platform with commodity hardware. Not that many years ago that would have been utopia :)
A few years from now you'll need that much horsepower to play Quake VIII. :)
Or run that years version of Windows ;-P
Morten Torstensen wrote:
Tru Huynh wrote:
[tru@quadcore ~]$ uname -a Linux quadcore 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 x86_64 x86_64 x86_64 GNU/Linux [tru@quadcore ~]$ grep -A4 processor /proc/cpuinfo processor : 0
Just take care with more than 8 CPUs, because you need the largesmp kernel then. Worked on a 8 socket, 16 CPU system where that was a pain due to binary kernel modules.
Now those machines could be 32 CPU systems... and you could add 8 sockets more. 64 CPUs on Intel platform with commodity hardware. Not that many years ago that would have been utopia :)
I believe those quad core Xeon "Clovertown" CPUs support hyperthreading too. which means 2 of them has 16 execution threads if you've enabled hyperthreading in the BIOS. While many people denigrate hyperthreading, we've got some Java messaging/database/middleware stuff that gets a HUGE boost on a older dual xeon* with HT enabled... this is with 2.8Ghz, 533Mhz FSB, 512K cache Xeons of this flavor:
# cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 2 model name : Intel(R) Xeon(TM) CPU 2.80GHz stepping : 7 cpu MHz : 2791.038 cache size : 512 KB physical id : 0 siblings : 2 runqueue : 0 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm bogomips : 5570.56
(repeat for processor 1,2,3)
John R Pierce wrote:
Morten Torstensen wrote:
Tru Huynh wrote:
[tru@quadcore ~]$ uname -a Linux quadcore 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 x86_64 x86_64 x86_64 GNU/Linux [tru@quadcore ~]$ grep -A4 processor /proc/cpuinfo processor : 0
Just take care with more than 8 CPUs, because you need the largesmp kernel then. Worked on a 8 socket, 16 CPU system where that was a pain due to binary kernel modules.
Now those machines could be 32 CPU systems... and you could add 8 sockets more. 64 CPUs on Intel platform with commodity hardware. Not that many years ago that would have been utopia :)
I believe those quad core Xeon "Clovertown" CPUs support hyperthreading too. which means 2 of them has 16 execution threads if you've enabled hyperthreading in the BIOS. While many people denigrate hyperthreading, we've got some Java messaging/database/middleware stuff that gets a HUGE boost on a older dual xeon* with HT enabled... this is with 2.8Ghz, 533Mhz FSB, 512K cache Xeons of this flavor:
I was astonished at the results of running this on an HT system: #!/usr/bin/perl #use integer; $i = 0; while ($i < 10000) { $j = 0; while ($j < 10000) { ++$j; } ++$i; }
[summer@bilby ~]$
More precisely, two of them together:
time bin/bm.perl&time bin/bm.perl
I don't think anything written in Perl is very cache-friendly, but the HT system performed about as I'd expect dual-core to.
I was astonished at the results of running this on an HT system: #!/usr/bin/perl #use integer; $i = 0; while ($i < 10000) { $j = 0; while ($j < 10000) { ++$j; } ++$i; }
[summer@bilby ~]$
More precisely, two of them together:
time bin/bm.perl&time bin/bm.perl
I don't think anything written in Perl is very cache-friendly, but the HT system performed about as I'd expect dual-core to. Cheers John
Im confused.
And just what were the astonishing results please?
- rh
-- Robert - Abba Communications Computer & Internet Services (509) 624-7159 - www.abbacomm.net
John R Pierce wrote:
Morten Torstensen wrote:
Tru Huynh wrote:
[tru@quadcore ~]$ uname -a Linux quadcore 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 x86_64 x86_64 x86_64 GNU/Linux [tru@quadcore ~]$ grep -A4 processor /proc/cpuinfo processor : 0
Just take care with more than 8 CPUs, because you need the largesmp kernel then. Worked on a 8 socket, 16 CPU system where that was a pain due to binary kernel modules.
Now those machines could be 32 CPU systems... and you could add 8 sockets more. 64 CPUs on Intel platform with commodity hardware. Not that many years ago that would have been utopia :)
I believe those quad core Xeon "Clovertown" CPUs support hyperthreading too. which means 2 of them has 16 execution threads if you've enabled hyperthreading in the BIOS. While many people denigrate hyperthreading, we've got some Java messaging/database/middleware stuff that gets a HUGE boost on a older dual xeon* with HT enabled... this is with 2.8Ghz, 533Mhz FSB, 512K cache Xeons of this flavor:
No "Core based" CPU that I've seen so far (Pentium M, Core, Core 2, Xeon 51xx) can enable hyperthreading though they will have the ht flag show up in /proc/cpuinfo. The ht flag though was present in every Pentium 4 CPU, it is not a solid indicator that Hyperthreading can be turned on. Don't ask me why this is, ask Intel...
Jay
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