linux_dsm_epyc7002/arch/x86
Andy Lutomirski 99c19e6a8f x86/vdso: Rearrange do_hres() to improve code generation
vgetcyc() is full of barriers, so fetching values out of the vvar
page before vgetcyc() for use after vgetcyc() results in poor code
generation.  Put vgetcyc() first to avoid this problem.

Also, pull the tv_sec division into the loop and put all the ts
writes together.  The old code wrote ts->tv_sec on each iteration
before the syscall fallback check and then added in the offset
afterwards, which forced the compiler to pointlessly copy base->sec
to ts->tv_sec on each iteration.  The new version seems to generate
sensible code.

Saves several cycles.  With this patch applied, the result is faster
than before the clock_gettime() rewrite.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/3c05644d010b72216aa286a6d20b5078d5fae5cd.1538762487.git.luto@kernel.org
2018-10-05 21:03:23 +02:00
..
boot x86/boot: Fix kexec booting failure in the SEV bit detection code 2018-09-27 19:35:03 +02:00
configs
crypto crypto: x86/aegis,morus - Do not require OSXSAVE for SSE2 2018-09-14 14:08:27 +08:00
entry x86/vdso: Rearrange do_hres() to improve code generation 2018-10-05 21:03:23 +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/hyper-v: rename ipi_arg_{ex,non_ex} structures 2018-09-20 00:51:42 +02:00
ia32 syscalls/x86: auto-create compat_sys_*() prototypes 2018-04-02 20:16:18 +02:00
include x86/vdso: Document vgtod_ts better 2018-10-05 10:12:18 +02:00
kernel x86/vdso: Enforce 64bit clocksource 2018-10-04 23:00:25 +02:00
kvm KVM: nVMX: Fix bad cleanup on error of get/set nested state IOCTLs 2018-09-20 18:54:08 +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: Expand static page table for fixmap space 2018-09-20 23:17:22 +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() before setting %cr3 2018-09-12 21:53:34 +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-rc5 2018-09-23 13:32:19 +02:00
.gitignore
Kbuild
Kconfig x86/time: Implement clocksource_arch_init() 2018-10-04 23:00:24 +02:00
Kconfig.cpu
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