linux.git/arch/x86/kernel/cpu/proc.c, branch v2.6.28 Linux kernel source tree x86/proc: fix /proc/cpuinfo cpu offline bug 2008-10-22T12:29:37+00:00 Lai Jiangshan laijs@cn.fujitsu.com 2008-10-22T04:42:30+00:00 bc8bcc79ea4203c7d04309f1307ab88c86f0b0cf Impact: fix missing CPUs in /proc/cpuinfo after CPU hotunplug/hotreplug In my test, I found that if a cpu has been offline, the next cpus may not be shown in the /proc/cpuinfo. if one read() cannot consume the whole /proc/cpuinfo, c_start() will be called again in the next read() calls. And *pos has been increased by 1 by the caller(seq_read()). if this time the cpu#*pos is offline, c_start() will return NULL, and the next cpus can not be shown. this fix use next_cpu_nr(*pos - 1, cpu_online_map) to search the next unshown cpu. the most easy way to reproduce this bug: 1) offline cpu#1 (cpu#0 is online) 2) dd ibs=2 if=/proc/cpuinfo the result is that only cpu#0 is shown. cpu#2 and cpu#3 .... cannot be shown in /proc/cpuinfo it's bug. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Impact: fix missing CPUs in /proc/cpuinfo after CPU hotunplug/hotreplug

In my test, I found that if a cpu has been offline,
the next cpus may not be shown in the /proc/cpuinfo.

if one read() cannot consume the whole /proc/cpuinfo,
c_start() will be called again in the next read() calls.
And *pos has been increased by 1 by the caller(seq_read()).
if this time the cpu#*pos is offline, c_start() will return
NULL, and the next cpus can not be shown.

this fix use next_cpu_nr(*pos - 1, cpu_online_map) to
search the next unshown cpu.

the most easy way to reproduce this bug:
1) offline cpu#1             (cpu#0 is online)
2) dd ibs=2 if=/proc/cpuinfo
   the result is that only cpu#0 is shown.
   cpu#2 and cpu#3 .... cannot be shown in /proc/cpuinfo
   it's bug.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/proc.c 2008-07-20T08:21:09+00:00 Mike Travis travis@sgi.com 2008-07-19T01:11:28+00:00 f2ad47ffeb1d292b7c7d1e2f6aedb37646c391db * Use nr_cpu_ids instead of NR_CPUS to limit traversal of cpu online map. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
  * Use nr_cpu_ids instead of NR_CPUS to limit traversal of cpu online map.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch: Remove unnecessary inclusions of asm/semaphore.h 2008-04-19T02:14:49+00:00 Matthew Wilcox matthew@wil.cx 2008-02-26T14:55:29+00:00 950e4da32426859ee4b37b2c95026d4f1efa5d05 None of these files use any of the functionality promised by asm/semaphore.h. It's possible that they rely on it dragging in some unrelated header file, but I can't build all these files, so we'll have fix any build failures as they come up. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> 
None of these files use any of the functionality promised by
asm/semaphore.h.  It's possible that they rely on it dragging in some
unrelated header file, but I can't build all these files, so we'll have
fix any build failures as they come up.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
x86: introduce initial apicid 2008-04-17T15:40:58+00:00 Yinghai Lu yhlu.kernel@gmail.com 2008-03-06T21:46:39+00:00 01aaea1afbcdb7c49fe4a567ebe3e295db9f720d store initial_apicid from early identify. it is could be different from phys_proc_id later. also print it out in /proc/cpuinfo. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
store initial_apicid from early identify. it is could be different from
phys_proc_id later.

also print it out in /proc/cpuinfo.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: show apicid for cpu in proc 2008-04-17T15:40:57+00:00 Yinghai Lu yhlu.kernel@gmail.com 2008-03-06T09:13:34+00:00 282bfe21cf0e2af9eac052c89bcc0a5ace80352f Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: cosmetic unification cpu/proc|_64.c 2008-04-17T15:40:48+00:00 Hiroshi Shimamoto h-shimamoto@ct.jp.nec.com 2008-02-20T18:48:02+00:00 2aef77204e1e3a8ed6345727afbcb2c1efdf7fc0 make cpu/proc.c and cpu/proc_64.c same. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
make cpu/proc.c and cpu/proc_64.c same.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: add power management line in /proc/cpuinfo 2008-04-17T15:40:48+00:00 Hiroshi Shimamoto h-shimamoto@ct.jp.nec.com 2008-02-20T18:47:12+00:00 f84c3a429f83a98bb0b0fd7eed7ad1edc512b91c Change /proc/cpuinfo on 32-bit, it will look like on 64-bit. 'power management' line is added and power management information will be printed at the line. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Change /proc/cpuinfo on 32-bit, it will look like on 64-bit.
'power management' line is added and power management information
will be printed at the line.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: make cpu/proc|_64.c similar 2008-04-17T15:40:48+00:00 Hiroshi Shimamoto h-shimamoto@ct.jp.nec.com 2008-02-20T18:45:29+00:00 a967ceac01cd3847011e2a777b8365b30afa770a clean up for unification. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
clean up for unification.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: unify CPU feature string names 2008-02-04T15:48:00+00:00 H. Peter Anvin hpa@zytor.com 2008-02-04T15:48:00+00:00 fa1408e4df53ec1e61f59c030b3488a1ef0c635d Move the CPU feature string names to a separate file (common to 32 and 64 bits); additionally, make <asm/cpufeature.h> includable by host code in preparation for including the CPU feature strings in the boot code. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> 
Move the CPU feature string names to a separate file (common to 32
and 64 bits); additionally, make <asm/cpufeature.h> includable by host
code in preparation for including the CPU feature strings in the boot
code.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
x86: constify function pointer tables 2008-01-30T12:33:32+00:00 Jan Engelhardt jengelh@computergmbh.de 2008-01-30T12:33:32+00:00 8a45eb31d832af5441703bf447c97f786ff850a4 Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> 
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>