On 10/1/2018 11:22 PM, Thomas Gleixner wrote:
On Mon, 1 Oct 2018, Mike Travis wrote:
Fix regression introduced by
commit cf7a63ef4e02 ("x86/tsc: Calibrate tsc only once")
as it changed setup_arch() so that it now calls tsc_early_init() before
acpi_boot_table_init() which is a necessary step, in the case of UV
systems, to inform tsc_sanitize_first_cpu() that we're on a platform
with async TSC resets as documented in
commit 341102c3ef29 ("x86/tsc: Add option that TSC on Socket 0 being non-zero is
valid")
Fix by skipping tsc_early_init() on UV systems and let TSC initialization
take place later in tsc_init().
Fixes: cf7a63ef4e02 ("x86/tsc: Calibrate tsc only once")
Signed-off-by: Mike Travis <mike.tra...@hpe.com>
Signed-off-by: Hedi Berriche <hedi.berri...@hpe.com>
See previous mail.
Reviewed-by: Russ Anderson <r...@hpe.com>
Reviewed-by: Dimitri Sivanich <sivan...@hpe.com>
---
arch/x86/kernel/setup.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- linux.orig/arch/x86/kernel/setup.c
+++ linux/arch/x86/kernel/setup.c
@@ -117,6 +117,7 @@
#include <asm/microcode.h>
#include <asm/kaslr.h>
#include <asm/unwind.h>
+#include <asm/uv/uv.h>
/*
* max_low_pfn_mapped: highest direct mapped pfn under 4GB
@@ -1015,7 +1016,10 @@ void __init setup_arch(char **cmdline_p)
*/
init_hypervisor_platform();
- tsc_early_init();
+ /* UV TSC multi-chassis synchronization already set, don't change it */
+ if (!is_early_uv_system())
+ tsc_early_init();
tsc_early_init() has already a check which makes it not invoke the
calibration code, so please put your uv check into that.
Will do, thanks.
Thanks,
tglx
