linux-stable/arch
James Hogan 1fa405552e MIPS: cevt-r4k: Dynamically calculate min_delta_ns
Calculate the MIPS clockevent device's min_delta_ns dynamically based on
the time it takes to perform the mips_next_event() sequence.

Virtualisation in particular makes the current fixed min_delta of 0x300
inappropriate under some circumstances, as the CP0_Count and CP0_Compare
registers may be being emulated by the hypervisor, and the frequency may
not correspond directly to the CPU frequency.

We actually use twice the median of multiple 75th percentiles of
multiple measurements of how long the mips_next_event() sequence takes,
in order to fairly efficiently eliminate outliers due to unexpected
hypervisor latency (which would need handling with retries when it
occurs during normal operation anyway).

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13176/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 15:30:25 +02:00
..
alpha alpha/extable: use generic search and sort routines 2016-03-22 15:36:02 -07:00
arc ARC: support HIGHMEM even without PAE40 2016-05-05 16:35:46 +05:30
arm Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm 2016-05-07 08:27:35 -07:00
arm64 Here are a couple last-minute fixes for ARM SoCs. Most of them 2016-05-05 15:31:35 -07:00
avr32
blackfin arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
c6x arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
cris Merge branch 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-20 19:08:56 -07:00
frv asm-generic changes for 4.6 2016-03-24 23:13:48 -07:00
h8300 h8300: switch EARLYCON 2016-03-25 01:45:19 +09:00
hexagon
ia64 [IA64] Enable preadv2 and pwritev2 syscalls for ia64 2016-03-25 14:37:32 -07:00
m32r
m68k Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2016-04-13 08:58:32 -07:00
metag arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
microblaze arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
mips MIPS: cevt-r4k: Dynamically calculate min_delta_ns 2016-05-13 15:30:25 +02:00
mn10300
nios2 nios2: memset: use the right constraint modifier for the %4 output operand 2016-04-27 16:35:55 +08:00
openrisc arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
parisc parisc: fix a bug when syscall number of tracee is __NR_Linux_syscalls 2016-05-06 15:09:07 +02:00
powerpc powerpc fixes for 4.6 #4 2016-05-06 11:05:07 -07:00
s390 s390/mm: fix asce_bits handling with dynamic pagetable levels 2016-04-21 09:50:09 +02:00
score
sh sh: fix function signature of cpu_coregroup_mask to match pointer type 2016-03-30 00:47:49 +00:00
sparc sparc64: Fix bootup regressions on some Kconfig combinations. 2016-04-27 17:27:37 -04:00
tile Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2016-03-28 15:04:55 -05:00
um fs/coredump: prevent fsuid=0 dumps into user-controlled directories 2016-03-22 15:36:02 -07:00
unicore32 Merge branch 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-20 19:08:56 -07:00
x86 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-06 12:59:27 -07:00
xtensa
.gitignore
Kconfig