diff options
| author | Siddha, Suresh B <suresh.b.siddha@intel.com> | 2005-11-05 17:25:54 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-14 19:55:16 -0800 |
| commit | 94605eff572b727aaad9b4b29bc358b919096503 (patch) | |
| tree | 657a848d8ef34d2f94bbad3aa4e5458d2d3f2d2b /include/linux/bitops.h | |
| parent | e90f22edf432512219cc2952f5811961abbd164f (diff) | |
| download | lwn-94605eff572b727aaad9b4b29bc358b919096503.tar.gz lwn-94605eff572b727aaad9b4b29bc358b919096503.zip | |
[PATCH] x86-64/i386: Intel HT, Multi core detection fixes
Fields obtained through cpuid vector 0x1(ebx[16:23]) and
vector 0x4(eax[14:25], eax[26:31]) indicate the maximum values and might not
always be the same as what is available and what OS sees. So make sure
"siblings" and "cpu cores" values in /proc/cpuinfo reflect the values as seen
by OS instead of what cpuid instruction says. This will also fix the buggy BIOS
cases (for example where cpuid on a single core cpu says there are "2" siblings,
even when HT is disabled in the BIOS.
http://bugzilla.kernel.org/show_bug.cgi?id=4359)
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/bitops.h')
| -rw-r--r-- | include/linux/bitops.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index cb3c3ef50f50..38c2fb7ebe09 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -84,6 +84,16 @@ static __inline__ int get_bitmask_order(unsigned int count) return order; /* We could be slightly more clever with -1 here... */ } +static __inline__ int get_count_order(unsigned int count) +{ + int order; + + order = fls(count) - 1; + if (count & (count - 1)) + order++; + return order; +} + /* * hweightN: returns the hamming weight (i.e. the number * of bits set) of a N-bit word |