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authorMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-07-22 07:40:55 -0400
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-07-22 07:40:55 -0400
commit3f98538c7673e5306a126fd3cb7e0a84abc170ee (patch)
treed8705fb9e21400a3e90423f52d3bd4b89327d485 /include/linux/timer.h
parentmedia: videodev2.h: change V4L2_PIX_FMT_BGRA444 define: fourcc was already in use (diff)
parentLinus 5.3-rc1 (diff)
Merge tag 'v5.3-rc1' into patchwork
Linus 5.3-rc1 * tag 'v5.3-rc1': (12816 commits) Linus 5.3-rc1 iommu/amd: fix a crash in iova_magazine_free_pfns hexagon: switch to generic version of pte allocation typo fix: it's d_make_root, not d_make_inode... dt-bindings: pinctrl: stm32: Fix missing 'clocks' property in examples dt-bindings: iio: ad7124: Fix dtc warnings in example dt-bindings: iio: avia-hx711: Fix avdd-supply typo in example dt-bindings: pinctrl: aspeed: Fix AST2500 example errors dt-bindings: pinctrl: aspeed: Fix 'compatible' schema errors dt-bindings: riscv: Limit cpus schema to only check RiscV 'cpu' nodes dt-bindings: Ensure child nodes are of type 'object' x86/entry/64: Prevent clobbering of saved CR2 value smp: Warn on function calls from softirq context KVM: x86: Add fixed counters to PMU filter KVM: nVMX: do not use dangling shadow VMCS after guest reset KVM: VMX: dump VMCS on failed entry KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed KVM: s390: Use kvm_vcpu_wake_up in kvm_s390_vcpu_wakeup KVM: Boost vCPUs that are delivering interrupts KVM: selftests: Remove superfluous define from vmx.c ...
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