linux_dsm_epyc7002/arch/x86
Daniel Vacek a786ef152c x86/tsc: Make calibration refinement more robust
The threshold in tsc_read_refs() is constant which may favor slower CPUs
but may not be optimal for simple reading of reference on faster ones.

Hence make it proportional to tsc_khz when available to compensate for
this. The threshold guards against any disturbance like IRQs, NMIs, SMIs
or CPU stealing by host on guest systems so rename it accordingly and
fix comments as well.

Also on some systems there is noticeable DMI bus contention at some point
during boot keeping the readout failing (observed with about one in ~300
boots when testing). In that case retry also the second readout instead of
simply bailing out unrefined. Usually the next second the readout returns
fast just fine without any issues.

Signed-off-by: Daniel Vacek <neelx@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/1541437840-29293-1-git-send-email-neelx@redhat.com
2018-11-06 21:53:15 +01:00
..
boot x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
configs x86/defconfig: Enable CONFIG_USB_XHCI_HCD=y 2018-10-10 08:29:51 +02:00
crypto crypto: x86/aes-ni - fix build error following fpu template removal 2018-10-08 13:47:02 +08:00
entry New gcc plugin: stackleak 2018-11-01 11:46:27 -07:00
events x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
hyperv Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 17:54:58 +01:00
ia32
include Merge branch 'core/urgent' into x86/urgent, to pick up objtool fix 2018-11-03 23:42:16 +01:00
kernel x86/tsc: Make calibration refinement more robust 2018-11-06 21:53:15 +01:00
kvm x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
lib Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 15:24:22 +01:00
math-emu
mm Merge branch 'core/urgent' into x86/urgent, to pick up objtool fix 2018-11-03 23:42:16 +01:00
net bpf, x32: Fix regression caused by commit 24dea04767 2018-07-26 02:51:12 +02:00
oprofile
pci mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
platform memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
power mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
purgatory kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
ras
realmode
tools x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
um Merge branch 'core/urgent' into x86/urgent, to pick up objtool fix 2018-11-03 23:42:16 +01:00
video
xen mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
.gitignore
Kbuild
Kconfig New gcc plugin: stackleak 2018-11-01 11:46:27 -07:00
Kconfig.cpu x86/cpu: Create Hygon Dhyana architecture support file 2018-09-27 16:14:05 +02:00
Kconfig.debug x86/kconfig: Remove redundant 'default n' lines from all x86 Kconfig's 2018-10-17 08:39:42 +02:00
Makefile kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs 2018-10-04 10:57:09 +02:00
Makefile_32.cpu
Makefile.um kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00