linux/include
Ulrich Obergfell 84d56e66b9 watchdog: new definitions and variables, initialization
The hardlockup and softockup had always been tied together.  Due to the
request of KVM folks, they had a need to have one enabled but not the
other.  Internally rework the code to split things apart more cleanly.

There is a bunch of churn here, but the end result should be code that
should be easier to maintain and fix without knowing the internals of what
is going on.

This patch (of 9):

Introduce new definitions and variables to separate the user interface in
/proc/sys/kernel from the internal run state of the lockup detectors.  The
internal run state is represented by two bits in a new variable that is
named 'watchdog_enabled'.  This helps simplify the code, for example:

- In order to check if any of the two lockup detectors is enabled,
  it is sufficient to check if 'watchdog_enabled' is not zero.

- In order to enable/disable one or both lockup detectors,
  it is sufficient to set/clear one or both bits in 'watchdog_enabled'.

- Concurrent updates of 'watchdog_enabled' need not be synchronized via
  a spinlock or a mutex. Updates can either be atomic or concurrency can
  be detected by using 'cmpxchg'.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:48:58 -07:00
..
acpi Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2015-02-19 11:28:36 -08:00
asm-generic OK, this has the big virtio 1.0 implementation, as specified by OASIS. 2015-02-18 09:24:01 -08:00
clocksource
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-02-14 09:47:01 -08:00
drm drm/ttm: device address space != CPU address space 2015-03-05 09:04:39 +10:00
dt-bindings USB patches for 4.1-rc1 2015-04-13 17:07:21 -07:00
keys
kvm KVM/ARM changes for v4.1: 2015-04-07 18:09:20 +02:00
linux watchdog: new definitions and variables, initialization 2015-04-14 16:48:58 -07:00
math-emu
media [media] media: atmel-isi: increase the burst length to improve the performance 2015-03-02 13:27:11 -03:00
memory
misc
net ipv6: protect skb->sk accesses from recursive dereference inside the stack 2015-04-06 16:12:49 -04:00
pcmcia
ras
rdma
rxrpc
scsi libata-eh: Set 'information' field for autosense 2015-03-27 11:59:22 -04:00
soc pm: at91: Workaround DDRSDRC self-refresh bug with LPDDR1 memories. 2015-03-03 19:43:59 +01:00
sound
target target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0 2015-03-19 23:26:46 -07:00
trace Merge branch 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2015-04-13 16:42:16 -07:00
uapi Staging driver patches for 4.1-rc1 2015-04-13 17:37:33 -07:00
video OMAPDSS: fix regression with display sysfs files 2015-02-26 10:23:15 +02:00
xen xen: Remove trailing semicolon from xenbus_register_frontend() definition 2015-03-02 10:38:59 +00:00
Kbuild