linux/arch
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
..
alpha mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
arm ARM: 5673/1: U300 fix initsection compile warning 2009-08-15 15:36:52 +01:00
avr32 mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
blackfin blackfin: fix wrong CTS inversion 2009-07-20 16:38:44 -07:00
cris mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
frv mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
h8300 sched: INIT_PREEMPT_COUNT 2009-07-10 14:24:05 -07:00
ia64 arch/ia64/kernel/iosapic: missing test after ioremap() 2009-08-11 14:52:11 -07:00
m32r mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
m68k mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
m68knommu Remove multiple KERN_ prefixes from printk formats 2009-07-08 10:30:03 -07:00
microblaze microblaze: Update Microblaze defconfigs 2009-08-18 11:05:11 +02:00
mips Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus 2009-08-17 13:39:52 -07:00
mn10300 MN10300: includecheck fix: mn10300, pci.h 2009-08-10 08:54:27 -07:00
parisc parisc: Set correct bit in protection flags 2009-08-02 12:36:05 +02:00
powerpc Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-08-10 11:48:51 -07:00
s390 Merge branch 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2009-08-09 14:58:21 -07:00
sh sh: sh7724 ddr self-refresh changes 2009-08-15 12:58:50 +09:00
sparc percpu, sparc64: fix sparse possible cpu map handling 2009-08-14 13:20:53 +09:00
um mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
x86 x86: don't call '->send_IPI_mask()' with an empty mask 2009-08-21 09:48:10 -07:00
xtensa mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
.gitignore
Kconfig gcov: add gcov profiling infrastructure 2009-06-18 13:03:57 -07:00