Re: [PATCH v3 2/2] x86: Add CPU-specific diagnostics to ld.so --list-diagnostics

["H.J. Lu" <hjl.tools@gmail.com>]

On Tue, Mar 2, 2021 at 6:32 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> ---
> v2: Adjustments to generic changes.  Add comments to cpu-features.h
>     pointing towards the diagnostics printer.
> v3: Use the new bit iterator.  Add _static_assert.
>
>  sysdeps/x86/dl-diagnostics-cpu.c   | 118 +++++++++++++++++++++++++++++++++++++
>  sysdeps/x86/include/cpu-features.h |   2 +
>  2 files changed, 120 insertions(+)
>
> diff --git a/sysdeps/x86/dl-diagnostics-cpu.c b/sysdeps/x86/dl-diagnostics-cpu.c
> new file mode 100644
> index 0000000000..5d9713f8d9
> --- /dev/null
> +++ b/sysdeps/x86/dl-diagnostics-cpu.c
> @@ -0,0 +1,118 @@
> +/* Print CPU diagnostics data in ld.so.  x86 version.
> +   Copyright (C) 2021 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <dl-diagnostics.h>
> +#include <ldsodefs.h>
> +
> +static void
> +print_cpu_features_value (const char *label, uint64_t value)
> +{
> +  _dl_printf ("x86.cpu_features.");
> +  _dl_diagnostics_print_labeled_value (label, value);
> +}
> +
> +static void
> +print_cpu_feature_internal (unsigned int index, const char *kind,
> +                            unsigned int reg, uint32_t value)
> +{
> +  _dl_printf ("x86.cpu_features.features[0x%x].%s[0x%x]=0x%x\n",
> +              index, kind, reg, value);
> +}
> +
> +static void
> +print_cpu_feature_preferred (const char *label, unsigned int flag)
> +{
> +  _dl_printf("x86.cpu_features.preferred.%s=0x%x\n", label, flag);
> +}
> +
> +void
> +_dl_diagnostics_cpu (void)
> +{
> +  const struct cpu_features *cpu_features = __get_cpu_features ();
> +
> +  print_cpu_features_value ("basic.kind", cpu_features->basic.kind);
> +  print_cpu_features_value ("basic.max_cpuid", cpu_features->basic.max_cpuid);
> +  print_cpu_features_value ("basic.family", cpu_features->basic.family);
> +  print_cpu_features_value ("basic.model", cpu_features->basic.model);
> +  print_cpu_features_value ("basic.stepping", cpu_features->basic.stepping);
> +
> +  for (unsigned int index = 0; index < CPUID_INDEX_MAX; ++index)
> +    {
> +      /* The index values are part of the ABI via
> +         <sys/platform/x86.h>, so translating them to strings is not
> +         necessary.  */
> +      for (unsigned int reg = 0; reg < 4; ++reg)
> +        print_cpu_feature_internal
> +          (index, "cpuid", reg,
> +           cpu_features->features[index].cpuid_array[reg]);
> +      for (unsigned int reg = 0; reg < 4; ++reg)
> +        print_cpu_feature_internal
> +          (index, "usable", reg,
> +           cpu_features->features[index].usable_array[reg]);
> +    }
> +
> +  /* The preferred indicators are not part of the ABI and need to be
> +     translated.  */
> +#define BIT(x) \
> +  print_cpu_feature_preferred (#x, CPU_FEATURE_PREFERRED_P (cpu_features, x));
> +#include "cpu-features-preferred_feature_index_1.def"
> +#undef BIT
> +
> +  print_cpu_features_value ("isa_1", cpu_features->isa_1);
> +  print_cpu_features_value ("xsave_state_size",
> +                            cpu_features->xsave_state_size);
> +  print_cpu_features_value ("xsave_state_full_size",
> +                            cpu_features->xsave_state_full_size);
> +  print_cpu_features_value ("data_cache_size", cpu_features->data_cache_size);
> +  print_cpu_features_value ("shared_cache_size",
> +                            cpu_features->shared_cache_size);
> +  print_cpu_features_value ("non_temporal_threshold",
> +                            cpu_features->non_temporal_threshold);
> +  print_cpu_features_value ("rep_movsb_threshold",
> +                            cpu_features->rep_movsb_threshold);
> +  print_cpu_features_value ("rep_movsb_stop_threshold",
> +                            cpu_features->rep_movsb_stop_threshold);
> +  print_cpu_features_value ("rep_stosb_threshold",
> +                            cpu_features->rep_stosb_threshold);
> +  print_cpu_features_value ("level1_icache_size",
> +                            cpu_features->level1_icache_size);
> +  print_cpu_features_value ("level1_dcache_size",
> +                            cpu_features->level1_dcache_size);
> +  print_cpu_features_value ("level1_dcache_assoc",
> +                            cpu_features->level1_dcache_assoc);
> +  print_cpu_features_value ("level1_dcache_linesize",
> +                            cpu_features->level1_dcache_linesize);
> +  print_cpu_features_value ("level2_cache_size",
> +                            cpu_features->level2_cache_size);
> +  print_cpu_features_value ("level2_cache_assoc",
> +                            cpu_features->level2_cache_assoc);
> +  print_cpu_features_value ("level2_cache_linesize",
> +                            cpu_features->level2_cache_linesize);
> +  print_cpu_features_value ("level3_cache_size",
> +                            cpu_features->level3_cache_size);
> +  print_cpu_features_value ("level3_cache_assoc",
> +                            cpu_features->level3_cache_assoc);
> +  print_cpu_features_value ("level3_cache_linesize",
> +                            cpu_features->level3_cache_linesize);
> +  print_cpu_features_value ("level4_cache_size",
> +                            cpu_features->level4_cache_size);
> +  _Static_assert (offsetof (struct cpu_features, level4_cache_size)
> +                  + sizeof (cpu_features->level4_cache_size)
> +                  == sizeof (*cpu_features),
> +                  "last cpu_features field has been printed");
> +}
> diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
> index 0fb988ead0..c5a779ba32 100644
> --- a/sysdeps/x86/include/cpu-features.h
> +++ b/sysdeps/x86/include/cpu-features.h
> @@ -839,6 +839,8 @@ struct cpuid_feature_internal
>      };
>  };
>
> +/* NB: When adding new fields, update sysdeps/x86/dl-diagnostics-cpu.c
> +   to print them.  */
>  struct cpu_features
>  {
>    struct cpu_features_basic basic;
>

OK.

Thanks.

-- 
H.J.