+ x86-show-cpuinfo-only-for-online-cpus.patch added to -mm tree

+ x86-show-cpuinfo-only-for-online-cpus.patch added to -mm tree

[akpm]

The patch titled
     x86: show cpuinfo only for online CPUs
has been added to the -mm tree.  Its filename is
     x86-show-cpuinfo-only-for-online-cpus.patch

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: x86: show cpuinfo only for online CPUs
From: "Andreas Herrmann" <andreas.herrmann3@amd.com>

Fix regressions introduced with 92cb7612aee39642d109b8d935ad265e602c0563.

It can happen that cpuinfo is displayed for CPUs that are not online or
even worse for CPUs not present at all. As an example, following was
shown for a "second" CPU of a single core K8 variant:

    processor       : 0
    vendor_id       : unknown
    cpu family      : 0
    model           : 0
    model name      : unknown
    stepping        : 0
    cache size      : 0 KB
    fpu             : yes
    fpu_exception   : yes
    cpuid level     : 0
    wp              : yes
    flags           :
    bogomips        : 0.00
    clflush size    : 0
    cache_alignment : 0
    address sizes   : 0 bits physical, 0 bits virtual
    power management:

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Glauber de Oliveira Costa <gcosta@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/kernel/cpu/proc.c |    8 +++-----
 arch/x86/kernel/setup_64.c |    8 +++-----
 2 files changed, 6 insertions(+), 10 deletions(-)

diff -puN arch/x86/kernel/cpu/proc.c~x86-show-cpuinfo-only-for-online-cpus arch/x86/kernel/cpu/proc.c
--- a/arch/x86/kernel/cpu/proc.c~x86-show-cpuinfo-only-for-online-cpus
+++ a/arch/x86/kernel/cpu/proc.c
@@ -90,8 +90,6 @@ static int show_cpuinfo(struct seq_file 
 
 #ifdef CONFIG_SMP
 	n = c->cpu_index;
-	if (!cpu_online(n))
-		return 0;
 #endif
 	seq_printf(m, "processor\t: %d\n"
 		"vendor_id\t: %s\n"
@@ -177,14 +175,14 @@ static int show_cpuinfo(struct seq_file 
 static void *c_start(struct seq_file *m, loff_t *pos)
 {
 	if (*pos == 0)	/* just in case, cpu 0 is not the first */
-		*pos = first_cpu(cpu_possible_map);
-	if ((*pos) < NR_CPUS && cpu_possible(*pos))
+		*pos = first_cpu(cpu_online_map);
+	if ((*pos) < NR_CPUS && cpu_online(*pos))
 		return &cpu_data(*pos);
 	return NULL;
 }
 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	*pos = next_cpu(*pos, cpu_possible_map);
+	*pos = next_cpu(*pos, cpu_online_map);
 	return c_start(m, pos);
 }
 static void c_stop(struct seq_file *m, void *v)
diff -puN arch/x86/kernel/setup_64.c~x86-show-cpuinfo-only-for-online-cpus arch/x86/kernel/setup_64.c
--- a/arch/x86/kernel/setup_64.c~x86-show-cpuinfo-only-for-online-cpus
+++ a/arch/x86/kernel/setup_64.c
@@ -1131,8 +1131,6 @@ static int show_cpuinfo(struct seq_file 
 
 
 #ifdef CONFIG_SMP
-	if (!cpu_online(c->cpu_index))
-		return 0;
 	cpu = c->cpu_index;
 #endif
 
@@ -1224,15 +1222,15 @@ static int show_cpuinfo(struct seq_file 
 static void *c_start(struct seq_file *m, loff_t *pos)
 {
 	if (*pos == 0)	/* just in case, cpu 0 is not the first */
-		*pos = first_cpu(cpu_possible_map);
-	if ((*pos) < NR_CPUS && cpu_possible(*pos))
+		*pos = first_cpu(cpu_online_map);
+	if ((*pos) < NR_CPUS && cpu_online(*pos))
 		return &cpu_data(*pos);
 	return NULL;
 }
 
 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	*pos = next_cpu(*pos, cpu_possible_map);
+	*pos = next_cpu(*pos, cpu_online_map);
 	return c_start(m, pos);
 }
 
_

Patches currently in -mm which might be from andreas.herrmann3@amd.com are

git-cpufreq.patch
x86-show-cpuinfo-only-for-online-cpus.patch

Re: + x86-show-cpuinfo-only-for-online-cpus.patch added to -mm tree

[Yinghai Lu]

On Nov 1, 2007 12:39 PM,  <akpm@linux-foundation.org> wrote:
>
> The patch titled
>      x86: show cpuinfo only for online CPUs
> has been added to the -mm tree.  Its filename is
>      x86-show-cpuinfo-only-for-online-cpus.patch
>
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
>
> See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
> out what to do about this
>
> ------------------------------------------------------
> Subject: x86: show cpuinfo only for online CPUs
> From: "Andreas Herrmann" <andreas.herrmann3@amd.com>
>
> Fix regressions introduced with 92cb7612aee39642d109b8d935ad265e602c0563.
>
> It can happen that cpuinfo is displayed for CPUs that are not online or
> even worse for CPUs not present at all. As an example, following was
> shown for a "second" CPU of a single core K8 variant:
>
>     processor       : 0
>     vendor_id       : unknown
>     cpu family      : 0
>     model           : 0
>     model name      : unknown
>     stepping        : 0
>     cache size      : 0 KB
>     fpu             : yes
>     fpu_exception   : yes
>     cpuid level     : 0
>     wp              : yes
>     flags           :
>     bogomips        : 0.00
>     clflush size    : 0
>     cache_alignment : 0
>     address sizes   : 0 bits physical, 0 bits virtual
>     power management:
>
> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
> Cc: Glauber de Oliveira Costa <gcosta@redhat.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Mike Travis <travis@sgi.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
>
>  arch/x86/kernel/cpu/proc.c |    8 +++-----
>  arch/x86/kernel/setup_64.c |    8 +++-----
>  2 files changed, 6 insertions(+), 10 deletions(-)
>
...
> diff -puN arch/x86/kernel/setup_64.c~x86-show-cpuinfo-only-for-online-cpus arch/x86/kernel/setup_64.c
> --- a/arch/x86/kernel/setup_64.c~x86-show-cpuinfo-only-for-online-cpus
> +++ a/arch/x86/kernel/setup_64.c
> @@ -1131,8 +1131,6 @@ static int show_cpuinfo(struct seq_file
>
>
>  #ifdef CONFIG_SMP
> -       if (!cpu_online(c->cpu_index))
> -               return 0;
>         cpu = c->cpu_index;
>  #endif

wonder if could change

>       if (!cpu_online(c->cpu_index))
>               return 0;

==>

>       if (c->cpu_index >= NR_CPUS)
>               return 0;

and add another entry for every cpu
online : 1 when it is enabled
or online : 0 when it is disabled by /sys/devices/system/cpuX/online.

YH

Re: + x86-show-cpuinfo-only-for-online-cpus.patch added to -mm tree

[Andreas Herrmann]

On Thu, Nov 01, 2007 at 03:31:23PM -0700, Yinghai Lu wrote:
> 
> wonder if could change
> 
> >       if (!cpu_online(c->cpu_index))
> >               return 0;
> 
> ==>
> 
> >       if (c->cpu_index >= NR_CPUS)
> >               return 0;
> 
> and add another entry for every cpu
> online : 1 when it is enabled
> or online : 0 when it is disabled by /sys/devices/system/cpuX/online.

No, I don't think that would be a good idea. It would change
the usual behaviour of that interface (to display only CPUs that
are "up and running".) 


Regards,

Andreas

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