watchdog: rename watchdog_suspend() and watchdog_resume()

Rename watchdog_suspend() to lockup_detector_suspend() and
watchdog_resume() to lockup_detector_resume() to avoid confusion with the
watchdog subsystem and to be consistent with the existing name
lockup_detector_init().

Also provide comment blocks to explain the watchdog_running and
watchdog_suspended variables and their relationship.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Stephane Eranian <eranian@google.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ulrich Obergfell 2015-09-04 15:45:28 -07:00 committed by Linus Torvalds
parent 999bbe49ea
commit ec6a90661a
3 changed files with 28 additions and 10 deletions

View File

@ -3627,7 +3627,7 @@ static __init int fixup_ht_bug(void)
return 0;
}
if (watchdog_suspend() != 0) {
if (lockup_detector_suspend() != 0) {
pr_debug("failed to disable PMU erratum BJ122, BV98, HSD29 workaround\n");
return 0;
}
@ -3638,7 +3638,7 @@ static __init int fixup_ht_bug(void)
x86_pmu.commit_scheduling = NULL;
x86_pmu.stop_scheduling = NULL;
watchdog_resume();
lockup_detector_resume();
get_online_cpus();

View File

@ -78,15 +78,15 @@ extern int proc_watchdog_thresh(struct ctl_table *, int ,
void __user *, size_t *, loff_t *);
extern int proc_watchdog_cpumask(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
extern int watchdog_suspend(void);
extern void watchdog_resume(void);
extern int lockup_detector_suspend(void);
extern void lockup_detector_resume(void);
#else
static inline int watchdog_suspend(void)
static inline int lockup_detector_suspend(void)
{
return 0;
}
static inline void watchdog_resume(void)
static inline void lockup_detector_resume(void)
{
}
#endif

View File

@ -67,8 +67,26 @@ unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
#define for_each_watchdog_cpu(cpu) \
for_each_cpu_and((cpu), cpu_online_mask, &watchdog_cpumask)
static int __read_mostly watchdog_suspended;
/*
* The 'watchdog_running' variable is set to 1 when the watchdog threads
* are registered/started and is set to 0 when the watchdog threads are
* unregistered/stopped, so it is an indicator whether the threads exist.
*/
static int __read_mostly watchdog_running;
/*
* If a subsystem has a need to deactivate the watchdog temporarily, it
* can use the suspend/resume interface to achieve this. The content of
* the 'watchdog_suspended' variable reflects this state. Existing threads
* are parked/unparked by the lockup_detector_{suspend|resume} functions
* (see comment blocks pertaining to those functions for further details).
*
* 'watchdog_suspended' also prevents threads from being registered/started
* or unregistered/stopped via parameters in /proc/sys/kernel, so the state
* of 'watchdog_running' cannot change while the watchdog is deactivated
* temporarily (see related code in 'proc' handlers).
*/
static int __read_mostly watchdog_suspended;
static u64 __read_mostly sample_period;
static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
@ -669,7 +687,7 @@ static void watchdog_unpark_threads(void)
/*
* Suspend the hard and soft lockup detector by parking the watchdog threads.
*/
int watchdog_suspend(void)
int lockup_detector_suspend(void)
{
int ret = 0;
@ -679,7 +697,7 @@ int watchdog_suspend(void)
* the 'watchdog_suspended' variable). If the watchdog threads are
* running, the first caller takes care that they will be parked.
* The state of 'watchdog_running' cannot change while a suspend
* request is active (see related changes in 'proc' handlers).
* request is active (see related code in 'proc' handlers).
*/
if (watchdog_running && !watchdog_suspended)
ret = watchdog_park_threads();
@ -695,7 +713,7 @@ int watchdog_suspend(void)
/*
* Resume the hard and soft lockup detector by unparking the watchdog threads.
*/
void watchdog_resume(void)
void lockup_detector_resume(void)
{
mutex_lock(&watchdog_proc_mutex);