Number of CPU
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From: fazlin on 13 Nov 2008 02:22 Hello All, Is there any kernel APIs or variable to find out the number of CPUs in a system. From user space, i can use /proc/cpuinfo file but is there a way to do it from kernel. Thanks in advance, Fazlin
From: Whiskers on 13 Nov 2008 07:47 On 2008-11-13, fazlin <fazlincse(a)gmail.com> wrote: > Hello All, > > Is there any kernel APIs or variable to find out the number of CPUs in > a system. From user space, i can use /proc/cpuinfo file but is there a > way to do it from kernel. > > Thanks in advance, > Fazlin If you mean 'is there a console command', try uname -p On my computer, I have a P4 HT, which uname identifies as one CPU - but /proc/cpuinfo is fooled by the two 'threads' supported by that chip into listing two CPUs. I've never used a system with two or more CPUs available, so I can't comment on what uname reports in such cases. You can extract the list of CPUs contained in /proc/cpuinfo using grep "model name" /proc/cpuinfo or just get a count using grep "model name" /proc/cpuinfo |wc -l See the man pages for uname, grep, and wc for more about what those commands do. -- -- ^^^^^^^^^^ -- Whiskers -- ~~~~~~~~~~
From: Martin Gregorie on 13 Nov 2008 15:36 On Thu, 13 Nov 2008 12:47:51 +0000, Whiskers wrote: > If you mean 'is there a console command', try > > uname -p > > On my computer, I have a P4 HT, which uname identifies as one CPU - but > /proc/cpuinfo is fooled by the two 'threads' supported by that chip into > listing two CPUs. I've never used a system with two or more CPUs > available, so I can't comment on what uname reports in such cases. > On my systems (one P3 Coppermine and a laptop with a Core Duo T2330) "uname -p" simply says 'i686' on both machines. -- martin@ | Martin Gregorie gregorie. | Essex, UK org |
From: Big and Blue on 13 Nov 2008 19:27 fazlin wrote: > Hello All, > > Is there any kernel APIs or variable to find out the number of CPUs in > a system. From user space, i can use /proc/cpuinfo file but is there a > way to do it from kernel. "From the kernel". Are you writing a kernel module? If not then /proc/cpuinfo *is* the kernel interface. -- Just because I've written it doesn't mean that either you or I have to believe it.
From: Johnny B Good on 13 Nov 2008 20:24
The message <gfi34c$sb0$6(a)localhost.localdomain> from Martin Gregorie <martin(a)see.sig.for.address.invalid> contains these words: > On Thu, 13 Nov 2008 12:47:51 +0000, Whiskers wrote: > > If you mean 'is there a console command', try > > > > uname -p > > > > On my computer, I have a P4 HT, which uname identifies as one CPU - but > > /proc/cpuinfo is fooled by the two 'threads' supported by that chip into > > listing two CPUs. I've never used a system with two or more CPUs > > available, so I can't comment on what uname reports in such cases. > > > On my systems (one P3 Coppermine and a laptop with a Core Duo T2330) > "uname -p" simply says 'i686' on both machines. That's awfully close to i666[1]. Just as well the subject title _wasn't_ Number Of The CPU. ;-) [1] I know, _The_Number_ wasn't actually 666, but I've forgotten the actual number now (for all I know, it might even have been 686 ;-) -- Regards, John. Please remove the "ohggcyht" before replying. The address has been munged to reject Spam-bots. |