From: chrisl@vmware.com
To: linux-kernel@vger.kernel.org
Subject: How to get number of physical CPU in linux from user space?
Date: Thu, 24 Oct 2002 16:02:29 -0700 [thread overview]
Message-ID: <20021024230229.GA1841@vmware.com> (raw)
It seems that /proc/cpuinfo will return the number of logical CPU.
If the machine has Intel Hyper-Thread enabled, that number is bigger
than physical CPU number. Usually twice as big.
My question is, what is the reliable way for user space program
to detect the number of physical CPU in the current machine?
If in it is in the kernel, I can read from cpu_sibling_map[]
or phys_cpu_id[]. But it seems not easy read that from
user space.
Of course I can do "gdb /proc/kcore" to get them. But is there
any better way?
Thanks in advance.
Chris
next reply other threads:[~2002-10-24 22:55 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-24 23:02 chrisl [this message]
2002-10-25 0:47 ` How to get number of physical CPU in linux from user space? Andrew Walrond
2002-10-25 8:26 ` Gianni Tedesco
2002-10-25 8:27 ` Martin J. Bligh
2002-10-25 18:20 ` chrisl
2002-10-25 18:35 ` David T Hollis
2002-10-25 18:52 ` Martin J. Bligh
2002-10-25 12:38 ` Dave Jones
2002-10-25 19:07 ` chrisl
-- strict thread matches above, loose matches on Subject: below --
2002-10-25 18:54 Nakajima, Jun
2002-10-25 19:12 ` chrisl
2002-10-25 19:05 Nakajima, Jun
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