Re: [PATCH] x86/smp: Fix __max_logical_packages value setup

From	Jiri Olsa <jolsa@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] x86/smp: Fix __max_logical_packages value setup
Date	2016-08-12 15:20 +0200
Message-ID	<s5kxs-26U-19@gated-at.bofh.it> (permalink)
References	(5 earlier) <s4GJH-j6-11@gated-at.bofh.it> <s4XAS-3T5-25@gated-at.bofh.it> <s4XUe-4eY-45@gated-at.bofh.it> <s4YwW-4uy-19@gated-at.bofh.it> <s5jL3-1y8-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Fri, Aug 12, 2016 at 02:24:57PM +0200, Jiri Olsa wrote:
> On Thu, Aug 11, 2016 at 03:46:51PM +0200, Peter Zijlstra wrote:
> > On Thu, Aug 11, 2016 at 03:05:21PM +0200, Jiri Olsa wrote:
> > > hum, so we either need some acpi solution to get number of all
> > > sockets or
> > 
> > This.. So the problem here is that the BIOS completely screws us over.
> > 
> > It wrecks the ACPI-ID table with that option to limit the number of CPUs
> > exposed to the OS (note that it didn't need to do that, it could have
> > enumerated them as empty, instead of not there at all) while keeping the
> > CPUID of the CPUs as reporting they have many (12? was it) cores.
> > 
> > This results in inconsistent state, and we're left with nothing useful.
> > 
> > > fix the uncore code to initialize pmu boxes on cpu hotplug as well
> > 
> > Can't.. it uses the boxes at STARTING time, and we can't do allocs
> > there. Not can we alloc earlier, because we don't know max_packages is
> > going to increase.
> 
> I still need to test this, but would this be something
> like you proposed on irc?

works on my test machine:

[    0.742505] smpboot: APIC(0) Converting physical 0 to logical package 0
[    0.749902] smpboot: APIC(20) Converting physical 1 to logical package 1
[    0.757390] smpboot: APIC(40) Converting physical 2 to logical package 2
[    0.764879] smpboot: APIC(60) Converting physical 3 to logical package 3
[    0.772368] smpboot: Detected more packages (4), then computed by BIOS data (1).
[    0.780630] smpboot: Max logical packages: 4


jirka

Thread

Re: [PATCH] x86/smp: Fix __max_logical_packages value setup Peter Zijlstra <peterz@infradead.org> - 2016-08-11 14:50 +0200
  Re: [PATCH] x86/smp: Fix __max_logical_packages value setup Jiri Olsa <jolsa@redhat.com> - 2016-08-11 15:10 +0200
    Re: [PATCH] x86/smp: Fix __max_logical_packages value setup Peter Zijlstra <peterz@infradead.org> - 2016-08-11 15:50 +0200
      Re: [PATCH] x86/smp: Fix __max_logical_packages value setup Jiri Olsa <jolsa@redhat.com> - 2016-08-12 14:30 +0200
        Re: [PATCH] x86/smp: Fix __max_logical_packages value setup Jiri Olsa <jolsa@redhat.com> - 2016-08-12 15:20 +0200
        Re: [PATCH] x86/smp: Fix __max_logical_packages value setup Peter Zijlstra <peterz@infradead.org> - 2016-08-15 11:10 +0200
          [PATCH] x86/smp: Fix __max_logical_packages value setup Jiri Olsa <jolsa@redhat.com> - 2016-08-15 12:20 +0200
            Re: [PATCH] x86/smp: Fix __max_logical_packages value setup Prarit Bhargava <prarit@redhat.com> - 2016-08-15 13:50 +0200
            [tip:x86/urgent] x86/smp: Fix __max_logical_packages value setup tip-bot for Jiri Olsa <tipbot@zytor.com> - 2016-08-18 13:00 +0200

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