linux-sg2042/arch/x86
Linus Torvalds b04e6373d6 x86: don't call '->send_IPI_mask()' with an empty mask
As noted in 83d349f35e ("x86: don't send
an IPI to the empty set of CPU's"), some APIC's will be very unhappy
with an empty destination mask.  That commit added a WARN_ON() for that
case, and avoided the resulting problem, but didn't fix the underlying
reason for why those empty mask cases happened.

This fixes that, by checking the result of 'cpumask_andnot()' of the
current CPU actually has any other CPU's left in the set of CPU's to be
sent a TLB flush, and not calling down to the IPI code if the mask is
empty.

The reason this started happening at all is that we started passing just
the CPU mask pointers around in commit 4595f9620 ("x86: change
flush_tlb_others to take a const struct cpumask"), and when we did that,
the cpumask was no longer thread-local.

Before that commit, flush_tlb_mm() used to create it's own copy of
'mm->cpu_vm_mask' and pass that copy down to the low-level flush
routines after having tested that it was not empty.  But after changing
it to just pass down the CPU mask pointer, the lower level TLB flush
routines would now get a pointer to that 'mm->cpu_vm_mask', and that
could still change - and become empty - after the test due to other
CPU's having flushed their own TLB's.

See

	http://bugzilla.kernel.org/show_bug.cgi?id=13933

for details.

Tested-by: Thomas Björnell <thomas.bjornell@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-21 09:48:10 -07:00
..
boot x86: fix usage of bios intcall() 2009-07-04 12:56:32 -07:00
configs Merge branch 'x86-kbuild-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-10 15:30:41 -07:00
crypto crypto: aes-ni - Remove CRYPTO_TFM_REQ_MAY_SLEEP from fpu template 2009-06-18 19:44:01 +08:00
ia32 Merge branch 'core/signal' into perfcounters/core 2009-04-30 21:16:49 +02:00
include/asm x86: Fix UV BAU destination subnode id 2009-08-15 11:58:02 +02:00
kernel x86: don't send an IPI to the empty set of CPU's 2009-08-21 09:23:57 -07:00
kvm KVM: MMU: limit rmap chain length 2009-08-06 12:06:54 +03:00
lguest lguest: update commentry 2009-07-30 16:03:46 +09:30
lib x86, msr: execute on the correct CPU subset 2009-08-03 14:48:13 -07:00
math-emu Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2 2009-03-27 17:28:43 +01:00
mm x86: don't call '->send_IPI_mask()' with an empty mask 2009-08-21 09:48:10 -07:00
oprofile x86/oprofile: rename kernel parameter for architectural perfmon to arch_perfmon 2009-07-10 05:22:50 +02:00
pci x86/pci: insert ioapic resource before assigning unassigned resources 2009-07-10 13:03:14 -07:00
power x86: Fix resume from suspend when CONFIG_CC_STACKPROTECTOR 2009-07-08 13:20:13 +02:00
vdso gcov: enable GCOV_PROFILE_ALL for x86_64 2009-06-18 13:03:58 -07:00
video
xen Merge branch 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-10 16:16:27 -07:00
Kbuild x86: standardize Kbuild rules 2009-04-16 18:09:02 +02:00
Kconfig perf_counter, x86: Fix/improve apic fallback 2009-08-12 14:12:49 +02:00
Kconfig.cpu Revert "x86, bts: reenable ptrace branch trace support" 2009-06-11 00:32:00 +02:00
Kconfig.debug kmemcheck: make kconfig accessible for other architectures 2009-06-15 15:49:17 +02:00
Makefile kmemcheck: add the kmemcheck core 2009-06-13 15:37:30 +02:00
Makefile_32.cpu