[IA64] Turn on CONFIG_HAVE_UNSTABLE_CLOCK

sched_clock() on ia64 is based on ar.itc, so is never completely synchronized between cpus. On some platforms (e.g. certain models of SGI Altix) it may be running at radically different frequencies. Based on a patch from Dimitri Sivanich which set this just for SN2 && GENERIC kernels ... it is needed for all ia64 machines. Signed-off-by: Tony Luck <tony.luck@intel.com>

[IA64] Turn on CONFIG_HAVE_UNSTABLE_CLOCK
sched_clock() on ia64 is based on ar.itc, so is never completely synchronized between cpus. On some platforms (e.g. certain models of SGI Altix) it may be running at radically different frequencies. Based on a patch from Dimitri Sivanich which set this just for SN2 && GENERIC kernels ... it is needed for all ia64 machines. Signed-off-by: Tony Luck <tony.luck@intel.com>
Tony Luck
1 parent 7a0b6e0143
Showing 1 changed file with 1 additions and 0 deletions Side-by-side Diff
arch/ia64/Kconfig
@@ -17,6 +17,7 @@
 	select ACPI if (!IA64_HP_SIM)
 	select PM if (!IA64_HP_SIM)
 	select ARCH_SUPPORTS_MSI
+	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_IDE
 	select HAVE_OPROFILE
 	select HAVE_KPROBES
...	...	@@ -17,6 +17,7 @@
17	17	select ACPI if (!IA64_HP_SIM)
18	18	select PM if (!IA64_HP_SIM)
19	19	select ARCH_SUPPORTS_MSI
	20	+ select HAVE_UNSTABLE_SCHED_CLOCK
20	21	select HAVE_IDE
21	22	select HAVE_OPROFILE
22	23	select HAVE_KPROBES