linux/arch/x86
Vivek Goyal 14cb6dcf0a x86, boot: Wait for boot cpu to show up if nr_cpus limit is about to hit
nr_cpus allows one to specify number of possible cpus in the system.
Current assumption seems to be that first cpu to show up is boot cpu
and this assumption will be broken in kdump scenario where we can be
booting on a non boot cpu with nr_cpus=1.

It might happen that first cpu we parse is not the cpu we boot on and
later we ignore boot cpu. Though code later seems to recognize this
anomaly and forcibly sets boot cpu in physical cpu map with following
warning.

if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
        printk(KERN_WARNING
                "weird, boot CPU (#%d) not listed by the BIOS.\n",
                hard_smp_processor_id());

        physid_set(hard_smp_processor_id(), phys_cpu_present_map);
}

This patch waits for boot cpu to show up and starts ignoring the cpus
once we have hit (nr_cpus - 1) number of cpus. So effectively we are
reserving one slot out of nr_cpus for boot cpu explicitly.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20110708171926.GF2930@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-08 15:33:35 -07:00
..
boot x86, setup: When probing memory with e801, use ax/bx as a pair 2011-04-25 14:52:37 -07:00
configs cgroup: remove the ns_cgroup 2011-05-26 17:12:34 -07:00
crypto crypto: aesni-intel - fix aesni build on i386 2011-05-18 09:03:34 +10:00
ia32 ns: Wire up the setns system call 2011-05-28 10:48:39 -07:00
include/asm watchdog: Intel SCU Watchdog: Fix build and remove duplicate code 2011-06-28 07:42:50 +00:00
kernel x86, boot: Wait for boot cpu to show up if nr_cpus limit is about to hit 2011-07-08 15:33:35 -07:00
kvm KVM: x86 emulator: fix %rip-relative addressing with immediate source operand 2011-06-29 10:09:25 +03:00
lguest lguest: fix timer interrupt setup 2011-05-30 11:14:10 +09:30
lib Merge branches 'x86-apic-for-linus', 'x86-asm-for-linus' and 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-05-19 17:49:35 -07:00
math-emu
mm x86, efi: Do not reserve boot services regions within reserved areas 2011-06-18 22:48:49 +02:00
net net: filter: Just In Time compiler for x86-64 2011-04-27 23:05:08 -07:00
oprofile Merge branch 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent 2011-06-08 15:49:03 +02:00
pci Merge branch 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen 2011-07-01 13:25:56 -07:00
platform x86, efi: Do not reserve boot services regions within reserved areas 2011-06-18 22:48:49 +02:00
power
tools
vdso x86: vdso: Remove unused variable 2011-05-26 13:17:35 +02:00
video
xen xen/mmu: Fix for linker errors when CONFIG_SMP is not defined. 2011-06-30 09:21:10 -04:00
.gitignore
Kbuild net: filter: Just In Time compiler for x86-64 2011-04-27 23:05:08 -07:00
Kconfig arch: remove CONFIG_GENERIC_FIND_{NEXT_BIT,BIT_LE,LAST_BIT} 2011-05-26 17:12:38 -07:00
Kconfig.cpu x86, cpu: Move AMD Elan Kconfig under "Processor family" 2011-04-08 13:01:25 -07:00
Kconfig.debug lib: consolidate DEBUG_STACK_USAGE option 2011-05-25 08:39:54 -07:00
Makefile
Makefile_32.cpu x86, cpu: Move AMD Elan Kconfig under "Processor family" 2011-04-08 13:01:25 -07:00