From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: michael@ellerman.id.au
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 17/18] powerpc/smp: Increase vdso_data->processorCount, not just decrease it
Date: Thu, 10 Mar 2011 14:46:01 +1100 [thread overview]
Message-ID: <1299728761.22236.467.camel@pasglop> (raw)
In-Reply-To: <1299728467.6272.49.camel@concordia>
On Thu, 2011-03-10 at 14:41 +1100, Michael Ellerman wrote:
>
> So the SYSTEM_RUNNING check is to avoid clashing with the logic in
> smp_setup_cpu_maps() I presume:
>
> arch/powerpc/kernel/setup-common.c: vdso_data->processorCount = num_present_cpus();
>
>
> But why not remove that, and let the increment in start_secondary() do
> all the work?
>
> With the current code if a cpu is present but fails to come up the count
> will be wrong I think.
I agree, on the other hand I'm worried about the way that things it
used in lparcfg.c (which looks bogus regardless) and it's not clear
to me what userspace uses it for (I bet some "licencing" stuff :-)
The lparcfg bit looks like something that should turn into counting
possible processors I suppose but it's hard to tell.
Cheers,
Ben.
next prev parent reply other threads:[~2011-03-10 3:46 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-08 6:37 [PATCHES] powerpc: Cleanup and fix CPU hotplug Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 01/18] powerpc: Make decrementer interrupt robust against offlined CPUs Benjamin Herrenschmidt
2011-03-10 8:01 ` Michael Ellerman
2011-03-08 6:37 ` [PATCH 02/18] powerpc/smp: soft-replugged CPUs must go back to start_secondary Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 03/18] powerpc/smp: Fix generic_mach_cpu_die() Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 04/18] powerpc/smp: Remove unused generic_cpu_enable() Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 05/18] powerpc/smp: Remove unused smp_ops->cpu_enable() Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 06/18] powerpc/pmac/smp: Fix 32-bit PowerMac cpu_die Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 07/18] powerpc/pmac/smp: Rename fixup_irqs() to migrate_irqs() and use it on ppc32 Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 08/18] powerpc/pmac/smp: Fixup smp_core99_cpu_disable() and use it on 64-bit Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 09/18] powerpc/pmac/smp: Consolidate 32-bit and 64-bit PowerMac cpu_die in one file Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 10/18] powerpc/pmac/smp: Remove HMT changes for PowerMac offline code Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 11/18] powerpc/pmac/smp: Properly NAP offlined CPU on G5 Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 12/18] powerpc/pmac: Rename cpu_state in therm_pm72 to avoid collision Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 13/18] powerpc/smp: Add a smp_ops->bringup_up() done callback Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 14/18] powerpc/pmac/smp: Fix CPU hotplug crashes on some machines Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 15/18] powerpc/smp: Don't expose per-cpu "cpu_state" array Benjamin Herrenschmidt
2011-03-29 5:37 ` Michael Ellerman
2011-03-29 8:13 ` Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 16/18] powerpc/smp: Create idle threads on demand and properly reset them Benjamin Herrenschmidt
2011-03-08 6:37 ` [PATCH 17/18] powerpc/smp: Increase vdso_data->processorCount, not just decrease it Benjamin Herrenschmidt
2011-03-10 3:41 ` Michael Ellerman
2011-03-10 3:46 ` Benjamin Herrenschmidt [this message]
2011-03-08 6:37 ` [PATCH 18/18] powerpc/pmac/smp: Remove no-longer needed preempt workaround Benjamin Herrenschmidt
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