Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-14 23:25:54 +00:00
Code Issues Packages Projects Releases Wiki Activity
16160c1946
linux/arch/x86
History
Jacek Tomaka 16160c1946 perf/x86/intel: Add support/quirk for the MISPREDICT bit on Knights Landing CPUs 
Problem: perf did not show branch predicted/mispredicted bit in brstack.

Output of perf -F brstack for profile collected

Before:

 0x4fdbcd/0x4fdc03/-/-/-/0
 0x45f4c1/0x4fdba0/-/-/-/0
 0x45f544/0x45f4bb/-/-/-/0
 0x45f555/0x45f53c/-/-/-/0
 0x7f66901cc24b/0x45f555/-/-/-/0
 0x7f66901cc22e/0x7f66901cc23d/-/-/-/0
 0x7f66901cc1ff/0x7f66901cc20f/-/-/-/0
 0x7f66901cc1e8/0x7f66901cc1fc/-/-/-/0

After:

 0x4fdbcd/0x4fdc03/P/-/-/0
 0x45f4c1/0x4fdba0/P/-/-/0
 0x45f544/0x45f4bb/P/-/-/0
 0x45f555/0x45f53c/P/-/-/0
 0x7f66901cc24b/0x45f555/P/-/-/0
 0x7f66901cc22e/0x7f66901cc23d/P/-/-/0
 0x7f66901cc1ff/0x7f66901cc20f/P/-/-/0
 0x7f66901cc1e8/0x7f66901cc1fc/P/-/-/0

Cause:

As mentioned in Software Development Manual vol 3, 17.4.8.1,
IA32_PERF_CAPABILITIES[5:0] indicates the format of the address that is
stored in the LBR stack. Knights Landing reports 1 (LBR_FORMAT_LIP) as
its format. Despite that, registers containing FROM address of the branch,
do have MISPREDICT bit but because of the format indicated in
IA32_PERF_CAPABILITIES[5:0], LBR did not read MISPREDICT bit.

Solution:

Teach LBR about above Knights Landing quirk and make it read MISPREDICT bit.

Signed-off-by: Jacek Tomaka <jacek.tomaka@poczta.fm>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180802013830.10600-1-jacekt@dugeo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-10 10:03:01 +02:00
..
boot Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
configs
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-08-29 13:38:39 -07:00
entry x86/vdso: Fix vDSO build if a retpoline is emitted 2018-08-20 18:04:41 +02:00
events perf/x86/intel: Add support/quirk for the MISPREDICT bit on Knights Landing CPUs 2018-09-10 10:03:01 +02:00
hyperv x86/mm: Only use tlb_remove_table() for paravirt 2018-08-23 11:56:31 -07:00
ia32 syscalls/x86: auto-create compat_sys_*() prototypes 2018-04-02 20:16:18 +02:00
include Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-09-09 07:05:15 -07:00
kernel x86/apic/vector: Make error return value negative 2018-09-08 12:12:40 +02:00
kvm KVM: LAPIC: Fix pv ipis out-of-bounds access 2018-09-07 18:38:43 +02:00
lib x86/nmi: Fix NMI uaccess race against CR3 switching 2018-08-31 17:08:22 +02:00
math-emu
mm x86/mm: Use WRITE_ONCE() when setting PTEs 2018-09-08 12:30:36 +02:00
net bpf, x32: Fix regression caused by commit 24dea04767 2018-07-26 02:51:12 +02:00
oprofile
pci PCI: Make early dump functionality generic 2018-06-29 20:06:07 -05:00
platform x86/efi: Load fixmap GDT in efi_call_phys_epilog() 2018-08-31 17:45:54 +02:00
power Power management updates for 4.19-rc1 2018-08-14 13:12:24 -07:00
purgatory kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
ras
realmode
tools x86/relocs: Add __end_rodata_aligned to S_REL 2018-08-09 20:42:07 +02:00
um Consolidation of Kconfig files by Christoph Hellwig. 2018-08-15 13:05:12 -07:00
video
xen xen: fixes for 4.19-rc2 2018-08-31 08:45:16 -07:00
.gitignore
Kbuild
Kconfig x86/Kconfig: Fix trivial typo 2018-08-27 10:29:14 +02:00
Kconfig.cpu Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-03-25 07:36:02 -10:00
Kconfig.debug Kconfig: consolidate the "Kernel hacking" menu 2018-08-02 08:06:48 +09:00
Makefile x86: Allow generating user-space headers without a compiler 2018-08-31 17:08:22 +02:00
Makefile_32.cpu
Makefile.um kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00