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authorThomas Gleixner <tglx@linutronix.de>2019-08-12 14:36:27 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-08-12 14:36:27 +0200
commitcbd32a1c56e36fedaa93a727699188bd3e6e6f67 (patch)
tree199e302eb5a66725a9d1774e47367a87098ba397 /include/linux/timer.h
parent48c7d73b2362ce61503551ad70052617b3e8857d (diff)
parentb61fbc887af7a13a1c90c84c1feaeb4c9780e1e2 (diff)
Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/urgent
Pull a single EFI fix for v5.3 from Ard: - Fix mixed mode breakage in EFI config table handling for TPM.
Diffstat (limited to 'include/linux/timer.h')
-rw-r--r--include/linux/timer.h27
1 files changed, 19 insertions, 8 deletions
diff --git a/include/linux/timer.h b/include/linux/timer.h
index 7b066fd38248..282e4f2a532a 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -36,19 +36,30 @@ struct timer_list {
#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
#endif
-/*
- * A deferrable timer will work normally when the system is busy, but
- * will not cause a CPU to come out of idle just to service it; instead,
- * the timer will be serviced when the CPU eventually wakes up with a
- * subsequent non-deferrable timer.
+/**
+ * @TIMER_DEFERRABLE: A deferrable timer will work normally when the
+ * system is busy, but will not cause a CPU to come out of idle just
+ * to service it; instead, the timer will be serviced when the CPU
+ * eventually wakes up with a subsequent non-deferrable timer.
*
- * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
- * the completion of the running instance from IRQ handlers, for example,
- * by calling del_timer_sync().
+ * @TIMER_IRQSAFE: An irqsafe timer is executed with IRQ disabled and
+ * it's safe to wait for the completion of the running instance from
+ * IRQ handlers, for example, by calling del_timer_sync().
*
* Note: The irq disabled callback execution is a special case for
* workqueue locking issues. It's not meant for executing random crap
* with interrupts disabled. Abuse is monitored!
+ *
+ * @TIMER_PINNED: A pinned timer will not be affected by any timer
+ * placement heuristics (like, NOHZ) and will always expire on the CPU
+ * on which the timer was enqueued.
+ *
+ * Note: Because enqueuing of timers can migrate the timer from one
+ * CPU to another, pinned timers are not guaranteed to stay on the
+ * initialy selected CPU. They move to the CPU on which the enqueue
+ * function is invoked via mod_timer() or add_timer(). If the timer
+ * should be placed on a particular CPU, then add_timer_on() has to be
+ * used.
*/
#define TIMER_CPUMASK 0x0003FFFF
#define TIMER_MIGRATING 0x00040000