[PATCH] How to get number of physical CPU in linux from user space?

[Robert Love <rml@tech9.net>]

On Fri, 2002-10-25 at 14:54, Nakajima, Jun wrote:

> Recent distributions or the AC tree has additional fields in
> /proc/cpu, which tell
> - physical package id
> - number of threads 

Attached patch for 2.5 adds the same fields the 2.4-ac tree have.  I
consider those "standard" enough.

Is this something HT users want?

	Robert Love

 proc.c |    5 +++++
 1 files changed, 5 insertions(+)

diff -urN linux-2.5.44/arch/i386/kernel/cpu/proc.c linux/arch/i386/kernel/cpu/proc.c
--- linux-2.5.44/arch/i386/kernel/cpu/proc.c	2002-10-19 00:02:29.000000000 -0400
+++ linux/arch/i386/kernel/cpu/proc.c	2002-10-25 15:06:23.000000000 -0400
@@ -17,6 +17,7 @@
 	 * applications want to get the raw CPUID data, they should access
 	 * /dev/cpu/<cpu_nr>/cpuid instead.
 	 */
+	extern int phys_proc_id[NR_CPUS];
 	static char *x86_cap_flags[] = {
 		/* Intel-defined */
 	        "fpu", "vme", "de", "pse", "tsc", "msr", "pae", "mce",
@@ -74,6 +75,10 @@
 	/* Cache size */
 	if (c->x86_cache_size >= 0)
 		seq_printf(m, "cache size\t: %d KB\n", c->x86_cache_size);
+#ifdef CONFIG_SMP
+	seq_printf(m, "physical processor ID\t: %d\n", phys_proc_id[n]);
+	seq_printf(m, "number of siblings\t: %d\n", smp_num_siblings);
+#endif
 	
 	/* We use exception 16 if we have hardware math and we've either seen it or the CPU claims it is internal */
 	fpu_exception = c->hard_math && (ignore_irq13 || cpu_has_fpu);