linux/arch/x86
Linus Torvalds d25e26b61d [x86] Clean up MAXSMP Kconfig, and limit NR_CPUS to 512
This fixes a regression that was indirectly caused by commit
1184dc2ffe ("x86: modify Kconfig to allow
up to 4096 cpus").

Allowing 4k CPU's is not practical at this time, because we still have a
number of places that have several 'cpumask_t's on the stack, and a
4k-bit cpumask is 512 bytes of stack-space for each such variable.  This
literally caused functions like 'smp_call_function_mask' to have a 2.5kB
stack frame, and several functions to have 2kB stackframes.

With an 8kB stack total, smashing the stack was simply much too likely.
At least bugzilla entry

	http://bugzilla.kernel.org/show_bug.cgi?id=11342

was due to this.

The earlier commit to not inline load_module() into sys_init_module()
fixed the particular symptoms of this that Alan Brunelle saw in that
bugzilla entry, but the huge stack waste by cpumask_t's was the more
direct cause.

Some day we'll have allocation helpers that allocate large CPU masks
dynamically, but in the meantime we simply cannot allow cpumasks this
large.

Cc: Alan D. Brunelle <Alan.Brunelle@hp.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-25 14:15:38 -07:00
..
boot x86: fix build warnings in real mode code 2008-08-18 09:20:14 +02:00
configs Subject: devmem, x86: fix rename of CONFIG_NONPROMISC_DEVMEM 2008-07-20 08:35:55 +02:00
crypto
ia32 tracehook: exec 2008-07-26 12:00:08 -07:00
kernel x86: fix cpufreq + sched_clock() regression 2008-08-25 14:39:19 +02:00
kvm KVM: MMU: Fix torn shadow pte 2008-08-25 17:24:27 +03:00
lguest lguest: set max_pfn_mapped, growl loudly at Yinghai Lu 2008-07-29 09:58:31 +10:00
lib x86: wrong register was used in align macro 2008-07-30 10:10:39 -07:00
mach-default x86: add ->pre_time_init to x86_quirks 2008-07-20 09:25:52 +02:00
mach-es7000 x86: move the last Dprintk instance to pr_debug() 2008-07-21 21:58:34 +02:00
mach-generic x86: make generic arch support NUMAQ, fix 2008-07-08 10:35:45 +02:00
mach-rdc321x removed unused #include <linux/version.h>'s 2008-08-23 12:14:12 -07:00
mach-voyager Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
math-emu x86: coding style fixes to arch/x86/math-emu/reg_constant 2008-06-18 15:00:13 +02:00
mm x86: fix two modpost warnings in mm/init_64.c 2008-08-22 07:51:54 +02:00
oprofile x86: fix oprofile + hibernation badness 2008-08-20 16:18:31 +02:00
pci Merge branch 'linus' into x86/urgent 2008-08-25 14:39:12 +02:00
power x86: fix i486 suspend to disk CR4 oops 2008-08-18 08:50:19 +02:00
vdso Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', 'x86/core', 'x86/cpu', 'x86/fixmap', 'x86/gart', 'x86/kprobes', 'x86/memtest', 'x86/modules', 'x86/nmi', 'x86/pat', 'x86/reboot', 'x86/setup', 'x86/step', 'x86/unify-pci', 'x86/uv', 'x86/xen' and 'xen-64bit' into x86/for-linus 2008-07-21 16:37:17 +02:00
video x86: video/fbdev.c: add MODULE_LICENSE 2008-05-04 20:04:46 +02:00
xen xen: don't use sysret for sysexit32 2008-07-24 12:28:12 +02:00
Kconfig [x86] Clean up MAXSMP Kconfig, and limit NR_CPUS to 512 2008-08-25 14:15:38 -07:00
Kconfig.cpu x86: fix crash due to missing debugctlmsr on AMD K6-3 2008-07-22 14:16:37 +02:00
Kconfig.debug x86: Fix help message for STRICT_DEVMEM config option 2008-07-21 13:04:08 -07:00
Makefile x86, RDC321x: add to mach-default 2008-07-26 13:51:46 +02:00
Makefile_32.cpu