Commit 3e8db224 authored Mar 18, 2016 by Thomas Gleixner

x86/topology: Use total_cpus not nr_cpu_ids for logical packages



nr_cpu_ids can be limited on the command line via nr_cpus=. That can break the
logical package management because it results in a smaller number of packages,
but the cpus to online are occupying the full package space as the hyper
threads are enumerated after the physical cores typically.

total_cpus is the real possible cpu space not limited by nr_cpus command line
and gives us the proper number of packages.

Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Fixes: 1f12e32f ("x86/topology: Create logical package id")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiong Zhou <jencce.kernel@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andreas Herrmann <aherrmann@suse.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1603181254330.3978@nanos

parent 63d1e995

arch/x86/kernel/smpboot.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -325,9 +325,14 @@ static void __init smp_init_package_map(void)
		* By not including this we'll sometimes over-estimate the number of
		* logical packages by the amount of !present siblings, but this is
		* still better than MAX_LOCAL_APIC.
		*
		* We use total_cpus not nr_cpu_ids because nr_cpu_ids can be limited
		* on the command line leading to a similar issue as the HT disable
		* problem because the hyperthreads are usually enumerated after the
		* primary cores.
		*/
		ncpus = boot_cpu_data.x86_max_cores;
		__max_logical_packages = DIV_ROUND_UP(nr_cpu_ids, ncpus);
		__max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus);

		/*
		* Possibly larger than what we need as the number of apic ids per