Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1228323

Re: [PATCH v4 0/2] Fix how CPUs are enumerated when there's more than 255 CPUs

Show all headers | View raw

On Wednesday, September 09, 2015 10:45:48 PM Rafael J. Wysocki wrote:
> On Wednesday, September 09, 2015 03:47:27 PM Lukasz Anaczkowski wrote:
> > This series of patches attempts to fix how CPUs are enumerated by kernel when
> > there's more than 255 of them on single processor.
> > In such case, BIOS may interleave APIC/X2APIC MADT subtables, to obey requirements
> > specified in ACPI spec. Without this patches, kernel then would first enumerate
> > BSP, then X2APIC then APIC, resulting in low APIC IDs to be assigned with high
> > logical IDs and high APIC IDs to be assigned low logical IDs. Biggest consequence
> > of that could be performance penalties due to wrong L2 cache sharing.
> > More details in patch 2/2.
> > 
> > Also, simpler approach has been considered, which did not required ACPI parsing
> > interface changes, however it failed to meet requirements. More details can be
> > found here: https://lkml.org/lkml/2015/9/7/285
> > 
> > Lukasz Anaczkowski (2):
> >   acpi: Added acpi_subtable_proc to ACPI table parsers
> >   x86, acpi: Handle apic/x2apic entries in MADT in correct order
> > 
> >  arch/x86/kernel/acpi/boot.c | 22 +++++++++--
> >  drivers/acpi/tables.c       | 91 ++++++++++++++++++++++++++++++++++++---------
> >  include/linux/acpi.h        | 19 ++++++++--
> >  3 files changed, 107 insertions(+), 25 deletions(-)
> 
> OK
> 
> Does anyone in the CC have any objections against merging this series?
> 
> If not, I'll queue it up as 4.3-rc material.

Well, I had a plan to push this for 4.3-rc2, but then I looked at it again
and realized that I'd like it to stay in linux-next for a couple of weeks
at least as I'm really unsure that it's not going to uncover some nastiness
somewhere.

Which practically means it's now scheduled for v4.4.

Thanks,
Rafael

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH] x86, arm64, acpi: Handle lapic/x2apic entries in MADT Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-08 13:10 +0200
  [PATCH 1/4] acpi: rename acpi_table_parse_entries Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-08 13:10 +0200
  [PATCH 0/4] Fix how CPUs are enumerated when there's more than 255 CPUs Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-08 13:10 +0200
    Re: [PATCH 0/4] Fix how CPUs are enumerated when there's more than  255 CPUs Marc Zyngier <marc.zyngier@arm.com> - 2015-09-08 18:30 +0200
      Re: [PATCH 0/4] Fix how CPUs are enumerated when there's more than  255 CPUs Al Stone <ahs3@redhat.com> - 2015-09-09 00:50 +0200
      RE: [PATCH 0/4] Fix how CPUs are enumerated when there's more than  255 CPUs "Anaczkowski, Lukasz" <lukasz.anaczkowski@intel.com> - 2015-09-09 09:10 +0200
      [PATCH 1/2] acpi: Added acpi_subtable_proc to ACPI table parsers Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-09 11:40 +0200
        [PATCH 2/2] x86, acpi: Handle apic/x2apic entries in MADT in correct order Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-09 11:40 +0200
          Re: [PATCH 2/2] x86, acpi: Handle apic/x2apic entries in MADT in  correct order Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2015-09-09 16:00 +0200
            RE: [PATCH 2/2] x86, acpi: Handle apic/x2apic entries in MADT in  correct order "Anaczkowski, Lukasz" <lukasz.anaczkowski@intel.com> - 2015-09-09 16:40 +0200
              Re: [PATCH 2/2] x86, acpi: Handle apic/x2apic entries in MADT in  correct order Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2015-09-09 17:50 +0200
        Re: [PATCH 1/2] acpi: Added acpi_subtable_proc to ACPI table parsers Marc Zyngier <marc.zyngier@arm.com> - 2015-09-09 12:50 +0200
          [PATCH v4 0/2] Fix how CPUs are enumerated when there's more than 255 CPUs Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-09 15:50 +0200
            [PATCH v4 1/2] acpi: Added acpi_subtable_proc to ACPI table parsers Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-09 15:50 +0200
              [PATCH v4 2/2] x86, acpi: Handle apic/x2apic entries in MADT in correct order Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-09 15:50 +0200
            Re: [PATCH v4 0/2] Fix how CPUs are enumerated when there's more than 255 CPUs "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2015-09-09 22:20 +0200
              Re: [PATCH v4 0/2] Fix how CPUs are enumerated when there's more than 255 CPUs "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2015-09-19 00:20 +0200
          Re: [PATCH 1/2] acpi: Added acpi_subtable_proc to ACPI table parsers Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-09 15:50 +0200
      [PATCH 0/2] Fix how CPUs are enumerated when there's more than 255 CPUs Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2015-09-09 11:40 +0200

csiph-web