linux/arch/powerpc
Nicholas Piggin d8e2a40535 powerpc/watchdog: Improve watchdog lock primitive
- Hard-disable interrupts before taking the lock, which prevents
  soft-NMI re-entrancy and therefore can prevent deadlocks.
- Use raw_ variants of local_irq_disable to avoid irq debugging.
- When the lock is contended, spin at low SMT priority, using
  loads only, and with interrupts enabled (where possible).

Some stalls have been noticed at high loads that go away with improved
locking. There should not be so much locking contention in the first
place (which is addressed in a subsequent patch), but locking should
still be improved.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-09 23:45:28 +10:00
..
boot powerpc/boot: Fix 64-bit boot wrapper build with non-biarch compiler 2017-07-28 19:35:46 +10:00
configs powerpc/configs: Re-enable HARD/SOFT lockup detectors 2017-08-09 23:45:13 +10:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-05-02 15:53:46 -07:00
include Linux v4.13-rc1 2017-07-31 20:20:29 +10:00
kernel powerpc/watchdog: Improve watchdog lock primitive 2017-08-09 23:45:28 +10:00
kvm Linux v4.13-rc1 2017-07-31 20:20:29 +10:00
lib powerpc fixes for 4.13 #2 2017-07-14 15:33:15 -07:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm Linux v4.13-rc1 2017-07-31 20:20:29 +10:00
net bpf: Add jited_len to struct bpf_prog 2017-06-06 15:41:24 -04:00
oprofile ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
perf powerpc/perf: Add POWER9 alternate PM_RUN_CYC and PM_RUN_INST_CMPL events 2017-07-12 12:21:49 +10:00
platforms powerpc/powernv/idle: Disable LOSE_FULL_CONTEXT states when stop-api fails 2017-08-08 20:21:23 +10:00
purgatory kexec, x86/purgatory: Unbreak it and clean it up 2017-03-10 20:55:09 +01:00
sysdev powerpc updates for 4.13 2017-07-07 13:55:45 -07:00
tools powerpc/64: Tool to check head sections location sanity 2017-05-30 14:59:51 +10:00
xmon powerpc/xmon: Add patch_instruction() support for xmon 2017-07-03 23:12:19 +10:00
Kconfig include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00
Kconfig.debug powerpc/xmon: Enable disassembly files (compilation changes) 2017-02-15 20:02:42 +11:00
Makefile powerpc/Makefile: Fix ld version check with 64-bit LE-only toolchain 2017-07-26 16:41:54 +10:00
Makefile.postlink powerpc/64: Tool to check head sections location sanity 2017-05-30 14:59:51 +10:00