Commit b70f4e85 authored Jun 30, 2010 by Tony Luck

[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 883a3acf
    [IA64] Re-implement spinaphores using ticket lock concepts

Reported via IRC by Bjorn Helgaas

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

parent 984bc960

arch/ia64/mm/tlb.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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();