Messages in this thread | | | Date | Tue, 2 Oct 2018 08:22:51 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 2/2] x86/tsc: Fix UV TSC initialization |
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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.travis@hpe.com> > Signed-off-by: Hedi Berriche <hedi.berriche@hpe.com>
See previous mail.
> Reviewed-by: Russ Anderson <rja@hpe.com> > Reviewed-by: Dimitri Sivanich <sivanich@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.
Thanks,
tglx
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