[Crash-utility] [PATCH] Display online cpus value in preference to kt->cpus

[Dave Anderson]

----- "Luciano Chavez" <lnx1138 at linux.vnet.ibm.com> wrote:

 > Hi Dave,
> > 
> > I like this particular solution best! Simple and straightforward.  I'll
> > work on a patch that does exactly as suggested. I'll post it for review
> > once I have it done this afternoon. Thanks for the help!
> 
> Below is the simpler revised patch. It applies and compiles to the
> latest crash 5.0.1 source cleanly. 
> 
> I still need to verify it still fixes the original problem. I am
> confident it will but just wanted to post the patch up first.
> 
> BTW, I was able to briefly access a POWER7 box this morning and
> confirmed that at least the CPU count displayed would be worse on one of
> those systems if indeed SMT was disabled and when using the current code
> minus the patch.

Queued for the next release.

Thanks,
  Dave

> 
> ~ # cat /sys/devices/system/cpu/online
> 0-23
> ~ # ppc64_cpu --smt=off
> ~ # cat /sys/devices/system/cpu/online
> 0,4,8,12,16,20
> 
> The current 5.0.1 code would display CPUS: 21 rather than CPUS: 6
> 
> Once I confirm the patch fixes this problem, I will post a followup.
> 
> -- 
> Luciano Chavez <lnx1138 at linux.vnet.ibm.com>
> IBM Linux Technology Center
> 
> diff -up crash-5.0.1/defs.h.old crash-5.0.1/defs.h
> --- crash-5.0.1/defs.h.old	2010-03-08 14:23:57.000000000 -0600
> +++ crash-5.0.1/defs.h	2010-03-08 14:34:29.000000000 -0600
> @@ -3717,6 +3717,7 @@ int get_cpus_online(void);
>  int get_cpus_present(void);
>  int get_cpus_possible(void);
>  int get_highest_cpu_online(void);
> +int get_cpus_to_display(void);
>  int in_cpu_map(int, int);
>  void paravirt_init(void);
>  void print_stack_text_syms(struct bt_info *, ulong, ulong);
> diff -up crash-5.0.1/kernel.c.old crash-5.0.1/kernel.c
> --- crash-5.0.1/kernel.c.old	2010-03-08 14:23:45.000000000 -0600
> +++ crash-5.0.1/kernel.c	2010-03-08 15:09:05.000000000 -0600
> @@ -3871,7 +3871,8 @@ display_sys_stats(void)
>  	}
>  	
>  
> -        fprintf(fp, "        CPUS: %d\n", kt->cpus);
> +	fprintf(fp, "        CPUS: %d\n", 
> +		machine_type("PPC64") ? get_cpus_to_display() : kt->cpus);
>  	if (ACTIVE())
>          	get_symbol_data("xtime", sizeof(struct timespec),
> &kt->date);
>          fprintf(fp, "        DATE: %s\n", 
> @@ -6256,6 +6257,18 @@ get_cpus_possible()
>  	return possible;
>  }
>  
> +
> +/*
> + *  For when displaying cpus, return the number of cpus online if
> possible, otherwise kt->cpus.
> + */
> +int
> +get_cpus_to_display(void)
> +{
> +	int online = get_cpus_online();
> +
> +	return (online ? online : kt->cpus);
> +}
> +
>  /*
>   *  Xen machine-address to pseudo-physical-page translator.
>   */ 
> diff -up crash-5.0.1/ppc64.c.old crash-5.0.1/ppc64.c
> --- crash-5.0.1/ppc64.c.old	2010-03-08 14:24:07.000000000 -0600
> +++ crash-5.0.1/ppc64.c	2010-03-08 14:38:10.000000000 -0600
> @@ -2215,7 +2215,7 @@ ppc64_display_machine_stats(void)
>  
>          fprintf(fp, "       MACHINE TYPE: %s\n", uts->machine);
>          fprintf(fp, "        MEMORY SIZE: %s\n",
> get_memory_size(buf));
> -        fprintf(fp, "               CPUS: %d\n", kt->cpus);
> +        fprintf(fp, "               CPUS: %d\n",
> get_cpus_to_display());
>          fprintf(fp, "    PROCESSOR SPEED: ");
>          if ((mhz = machdep->processor_speed()))
>                  fprintf(fp, "%ld Mhz\n", mhz);
> 
> 
> --
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