[git pull] ia64 changes

Luck, Tony
2010-07-01T15:22:02Z

Regression dates back to 2.6.32 - but I think this fits into the
"serious" bug category for late inclusion.

Thanks!

-Tony

arch/ia64/mm/tlb.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

Tony Luck (1):
[IA64] Fix spinaphore down_spin()

commit b70f4e85bfc4d7000036355b714a92d5c574f1be
Author: Tony Luck <tony.luck@intel.com>
Date: Wed Jun 30 10:46:16 2010 -0700

[IA64] Fix spinaphore down_spin()

Typo in down_spin() meant it only read the low 32 bits of the
"serve" value, instead of the full 64 bits. This results in the
system hanging when the values in ticket/serve get larger than
32-bits. A big enough system running the right test can hit this
in a just a few hours.

Broken since 883a3acf5b0d4782ac35981227a0d094e8b44850
[IA64] Re-implement spinaphores using ticket lock concepts

Reported via IRC by Bjorn Helgaas

Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c
index 5dfd916..7b3cdc6 100644
--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -121,7 +121,7 @@ static inline void down_spin(struct spinaphore *ss)
ia64_invala();

for (;;) {
- asm volatile ("ld4.c.nc %0=[%1]" : "=r"(serve) : "r"(&ss->serve) : "memory");
+ asm volatile ("ld8.c.nc %0=[%1]" : "=r"(serve) : "r"(&ss->serve) : "memory");
if (time_before(t, serve))
return;
cpu_relax();