25 files changed, 171 insertions, 102 deletions

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 9d5904cc7712..9b504af2e966 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -5,7 +5,6 @@ config ALPHA
         select HAVE_IDE
         select HAVE_OPROFILE
         select HAVE_SYSCALL_WRAPPERS
-        select HAVE_IRQ_WORK
         select HAVE_PCSPKR_PLATFORM
         select HAVE_PERF_EVENTS
         select HAVE_DMA_ATTRS
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 67874b82a4ed..9bbe760f2352 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -36,7 +36,6 @@ config ARM
         select HAVE_GENERIC_HARDIRQS
         select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7))
         select HAVE_IDE if PCI || ISA || PCMCIA
-        select HAVE_IRQ_WORK
         select HAVE_KERNEL_GZIP
         select HAVE_KERNEL_LZMA
         select HAVE_KERNEL_LZO
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f8f362aafee9..75e915b72471 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -21,7 +21,6 @@ config ARM64
         select HAVE_GENERIC_DMA_COHERENT
         select HAVE_GENERIC_HARDIRQS
         select HAVE_HW_BREAKPOINT if PERF_EVENTS
-        select HAVE_IRQ_WORK
         select HAVE_MEMBLOCK
         select HAVE_PERF_EVENTS
         select IRQ_DOMAIN
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index b6f3ad5441c5..67e4aaad78f5 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -24,7 +24,6 @@ config BLACKFIN
         select HAVE_FUNCTION_TRACER
         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
         select HAVE_IDE
-        select HAVE_IRQ_WORK
         select HAVE_KERNEL_GZIP if RAMKERNEL
         select HAVE_KERNEL_BZIP2 if RAMKERNEL
         select HAVE_KERNEL_LZMA if RAMKERNEL
@@ -38,7 +37,6 @@ config BLACKFIN
         select HAVE_GENERIC_HARDIRQS
         select GENERIC_ATOMIC64
         select GENERIC_IRQ_PROBE
-        select IRQ_PER_CPU if SMP
         select USE_GENERIC_SMP_HELPERS if SMP
         select HAVE_NMI_WATCHDOG if NMI_WATCHDOG
         select GENERIC_SMP_IDLE_THREAD
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 9d262645f667..17df48fc8f44 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -3,7 +3,6 @@ config FRV
         default y
         select HAVE_IDE
         select HAVE_ARCH_TRACEHOOK
-        select HAVE_IRQ_WORK
         select HAVE_PERF_EVENTS
         select HAVE_UID16
         select HAVE_GENERIC_HARDIRQS
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 0744f7d7b1fd..e4decc6b8947 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -12,9 +12,7 @@ config HEXAGON
         # select ARCH_WANT_OPTIONAL_GPIOLIB
         # select ARCH_REQUIRE_GPIOLIB
         # select HAVE_CLK
-        # select IRQ_PER_CPU
         # select GENERIC_PENDING_IRQ if SMP
-        select HAVE_IRQ_WORK
         select GENERIC_ATOMIC64
         select HAVE_PERF_EVENTS
         select HAVE_GENERIC_HARDIRQS
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 3279646120e3..00c2e88f7755 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -29,7 +29,6 @@ config IA64
         select ARCH_DISCARD_MEMBLOCK
         select GENERIC_IRQ_PROBE
         select GENERIC_PENDING_IRQ if SMP
-        select IRQ_PER_CPU
         select GENERIC_IRQ_SHOW
         select ARCH_WANT_OPTIONAL_GPIOLIB
         select ARCH_HAVE_NMI_SAFE_CMPXCHG
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2ac626ab9d43..9becc44d9d7a 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -4,7 +4,6 @@ config MIPS
         select HAVE_GENERIC_DMA_COHERENT
         select HAVE_IDE
         select HAVE_OPROFILE
-        select HAVE_IRQ_WORK
         select HAVE_PERF_EVENTS
         select PERF_USE_VMALLOC
         select HAVE_ARCH_KGDB
@@ -2161,7 +2160,6 @@ source "mm/Kconfig"
 config SMP
         bool "Multi-Processing support"
         depends on SYS_SUPPORTS_SMP
-        select IRQ_PER_CPU
         select USE_GENERIC_SMP_HELPERS
         help
           This enables support for systems with more than one CPU. If you have
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index b77feffbadea..a32e34ecda9e 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -9,14 +9,12 @@ config PARISC
         select RTC_DRV_GENERIC
         select INIT_ALL_POSSIBLE
         select BUG
-        select HAVE_IRQ_WORK
         select HAVE_PERF_EVENTS
         select GENERIC_ATOMIC64 if !64BIT
         select HAVE_GENERIC_HARDIRQS
         select BROKEN_RODATA
         select GENERIC_IRQ_PROBE
         select GENERIC_PCI_IOMAP
-        select IRQ_PER_CPU
         select ARCH_HAVE_NMI_SAFE_CMPXCHG
         select GENERIC_SMP_IDLE_THREAD
         select GENERIC_STRNCPY_FROM_USER
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 17903f1f356b..561ccca7b1a7 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -118,14 +118,12 @@ config PPC
         select HAVE_SYSCALL_WRAPPERS if PPC64
         select GENERIC_ATOMIC64 if PPC32
         select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
-        select HAVE_IRQ_WORK
         select HAVE_PERF_EVENTS
         select HAVE_REGS_AND_STACK_ACCESS_API
         select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
         select HAVE_GENERIC_HARDIRQS
         select ARCH_WANT_IPC_PARSE_VERSION
         select SPARSE_IRQ
-        select IRQ_PER_CPU
         select IRQ_DOMAIN
         select GENERIC_IRQ_SHOW
         select GENERIC_IRQ_SHOW_LEVEL
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b5ea38c25647..c15ba7d1be64 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -78,7 +78,6 @@ config S390
         select HAVE_KVM if 64BIT
         select HAVE_ARCH_TRACEHOOK
         select INIT_ALL_POSSIBLE
-        select HAVE_IRQ_WORK
         select HAVE_PERF_EVENTS
         select ARCH_HAVE_NMI_SAFE_CMPXCHG
         select HAVE_DEBUG_KMEMLEAK
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index babc2b826c5c..9c833c585871 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -11,7 +11,6 @@ config SUPERH
         select HAVE_ARCH_TRACEHOOK
         select HAVE_DMA_API_DEBUG
         select HAVE_DMA_ATTRS
-        select HAVE_IRQ_WORK
         select HAVE_PERF_EVENTS
         select HAVE_DEBUG_BUGVERBOSE
         select ARCH_HAVE_CUSTOM_GPIO_H
@@ -91,9 +90,6 @@ config GENERIC_CSUM
 config GENERIC_HWEIGHT
         def_bool y
 
-config IRQ_PER_CPU
-        def_bool y
-
 config GENERIC_GPIO
         def_bool n
 
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index cb9c333d74e8..9bff3db17c8c 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -23,7 +23,6 @@ config SPARC
         select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
         select RTC_CLASS
         select RTC_DRV_M48T59
-        select HAVE_IRQ_WORK
         select HAVE_DMA_ATTRS
         select HAVE_DMA_API_DEBUG
         select HAVE_ARCH_JUMP_LABEL
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 225543bf45a5..36b05ed0bb3c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -28,7 +28,6 @@ config X86
         select HAVE_OPROFILE
         select HAVE_PCSPKR_PLATFORM
         select HAVE_PERF_EVENTS
-        select HAVE_IRQ_WORK
         select HAVE_IOREMAP_PROT
         select HAVE_KPROBES
         select HAVE_MEMBLOCK
diff --git a/drivers/staging/iio/trigger/Kconfig b/drivers/staging/iio/trigger/Kconfig
index 7d3207559265..d44d3ad26fa5 100644
--- a/drivers/staging/iio/trigger/Kconfig
+++ b/drivers/staging/iio/trigger/Kconfig
@@ -21,7 +21,6 @@ config IIO_GPIO_TRIGGER
 config IIO_SYSFS_TRIGGER
         tristate "SYSFS trigger"
         depends on SYSFS
-        depends on HAVE_IRQ_WORK
         select IRQ_WORK
         help
           Provides support for using SYSFS entry as IIO triggers.
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 6a9e8f5399e2..f5dbce50466e 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -3,6 +3,20 @@
 
 #include <linux/llist.h>
 
+/*
+ * An entry can be in one of four states:
+ *
+ * free      NULL, 0 -> {claimed}       : free to be used
+ * claimed   NULL, 3 -> {pending}       : claimed to be enqueued
+ * pending   next, 3 -> {busy}          : queued, pending callback
+ * busy      NULL, 2 -> {free, claimed} : callback in progress, can be claimed
+ */
+
+#define IRQ_WORK_PENDING        1UL
+#define IRQ_WORK_BUSY           2UL
+#define IRQ_WORK_FLAGS          3UL
+#define IRQ_WORK_LAZY           4UL /* Doesn't want IPI, wait for tick */
+
 struct irq_work {
         unsigned long flags;
         struct llist_node llnode;
@@ -16,8 +30,14 @@ void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *))
         work->func = func;
 }
 
-bool irq_work_queue(struct irq_work *work);
+void irq_work_queue(struct irq_work *work);
 void irq_work_run(void);
 void irq_work_sync(struct irq_work *work);
 
+#ifdef CONFIG_IRQ_WORK
+bool irq_work_needs_cpu(void);
+#else
+static bool irq_work_needs_cpu(void) { return false; }
+#endif
+
 #endif /* _LINUX_IRQ_WORK_H */
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 9afc01e5a0a6..86c4b6294713 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -98,9 +98,6 @@ int no_printk(const char *fmt, ...)
 extern asmlinkage __printf(1, 2)
 void early_printk(const char *fmt, ...);
 
-extern int printk_needs_cpu(int cpu);
-extern void printk_tick(void);
-
 #ifdef CONFIG_PRINTK
 asmlinkage __printf(5, 0)
 int vprintk_emit(int facility, int level,
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 1a6567b48492..553272e6af55 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -8,6 +8,8 @@
 
 #include <linux/clockchips.h>
 #include <linux/irqflags.h>
+#include <linux/percpu.h>
+#include <linux/hrtimer.h>
 
 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 
@@ -122,13 +124,26 @@ static inline int tick_oneshot_mode_active(void) { return 0; }
 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 
 # ifdef CONFIG_NO_HZ
+DECLARE_PER_CPU(struct tick_sched, tick_cpu_sched);
+
+static inline int tick_nohz_tick_stopped(void)
+{
+        return __this_cpu_read(tick_cpu_sched.tick_stopped);
+}
+
 extern void tick_nohz_idle_enter(void);
 extern void tick_nohz_idle_exit(void);
 extern void tick_nohz_irq_exit(void);
 extern ktime_t tick_nohz_get_sleep_length(void);
 extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
 extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
-# else
+
+# else /* !CONFIG_NO_HZ */
+static inline int tick_nohz_tick_stopped(void)
+{
+        return 0;
+}
+
 static inline void tick_nohz_idle_enter(void) { }
 static inline void tick_nohz_idle_exit(void) { }
 
diff --git a/init/Kconfig b/init/Kconfig
index b023334df142..dcb68ac42b78 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -20,12 +20,8 @@ config CONSTRUCTORS
         bool
         depends on !UML
 
-config HAVE_IRQ_WORK
-        bool
-
 config IRQ_WORK
         bool
-        depends on HAVE_IRQ_WORK
 
 config BUILDTIME_EXTABLE_SORT
         bool
@@ -1273,6 +1269,7 @@ config HOTPLUG
 config PRINTK
         default y
         bool "Enable support for printk" if EXPERT
+        select IRQ_WORK
         help
           This option enables normal printk support. Removing it
           eliminates most of the message strings from the kernel image
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e49a288fa479..88e7bed62711 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1524,6 +1524,7 @@ void enable_percpu_irq(unsigned int irq, unsigned int type)
 out:
         irq_put_desc_unlock(desc, flags);
 }
+EXPORT_SYMBOL_GPL(enable_percpu_irq);
 
 void disable_percpu_irq(unsigned int irq)
 {
@@ -1537,6 +1538,7 @@ void disable_percpu_irq(unsigned int irq)
         irq_percpu_disable(desc, cpu);
         irq_put_desc_unlock(desc, flags);
 }
+EXPORT_SYMBOL_GPL(disable_percpu_irq);
 
 /*
  * Internal function to unregister a percpu irqaction.
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 611cd6003c45..7b5f012bde9d 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -80,13 +80,11 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force)
 
         /*
          * All handlers must agree on IRQF_SHARED, so we test just the
-         * first. Check for action->next as well.
+         * first.
          */
         action = desc->action;
         if (!action || !(action->flags & IRQF_SHARED) ||
-            (action->flags & __IRQF_TIMER) ||
-            (action->handler(irq, action->dev_id) == IRQ_HANDLED) ||
-            !action->next)
+            (action->flags & __IRQF_TIMER))
                 goto out;
 
         /* Already running on another processor */
@@ -104,6 +102,7 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force)
         do {
                 if (handle_irq_event(desc) == IRQ_HANDLED)
                         ret = IRQ_HANDLED;
+                /* Make sure that there is still a valid action */
                 action = desc->action;
         } while ((desc->istate & IRQS_PENDING) && action);
         desc->istate &= ~IRQS_POLL_INPROGRESS;
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 1588e3b2871b..55fcce6065cf 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -12,37 +12,36 @@
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
 #include <linux/irqflags.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
 #include <asm/processor.h>
 
-/*
- * An entry can be in one of four states:
- *
- * free      NULL, 0 -> {claimed}       : free to be used
- * claimed   NULL, 3 -> {pending}       : claimed to be enqueued
- * pending   next, 3 -> {busy}          : queued, pending callback
- * busy      NULL, 2 -> {free, claimed} : callback in progress, can be claimed
- */
-
-#define IRQ_WORK_PENDING        1UL
-#define IRQ_WORK_BUSY           2UL
-#define IRQ_WORK_FLAGS          3UL
 
 static DEFINE_PER_CPU(struct llist_head, irq_work_list);
+static DEFINE_PER_CPU(int, irq_work_raised);
 
 /*
  * Claim the entry so that no one else will poke at it.
  */
 static bool irq_work_claim(struct irq_work *work)
 {
-        unsigned long flags, nflags;
+        unsigned long flags, oflags, nflags;
 
+        /*
+         * Start with our best wish as a premise but only trust any
+         * flag value after cmpxchg() result.
+         */
+        flags = work->flags & ~IRQ_WORK_PENDING;
         for (;;) {
-                flags = work->flags;
-                if (flags & IRQ_WORK_PENDING)
-                        return false;
                 nflags = flags | IRQ_WORK_FLAGS;
-                if (cmpxchg(&work->flags, flags, nflags) == flags)
+                oflags = cmpxchg(&work->flags, flags, nflags);
+                if (oflags == flags)
                         break;
+                if (oflags & IRQ_WORK_PENDING)
+                        return false;
+                flags = oflags;
                 cpu_relax();
         }
 
@@ -57,57 +56,69 @@ void __weak arch_irq_work_raise(void)
 }
 
 /*
- * Queue the entry and raise the IPI if needed.
+ * Enqueue the irq_work @entry unless it's already pending
+ * somewhere.
+ *
+ * Can be re-enqueued while the callback is still in progress.
  */
-static void __irq_work_queue(struct irq_work *work)
+void irq_work_queue(struct irq_work *work)
 {
-        bool empty;
+        /* Only queue if not already pending */
+        if (!irq_work_claim(work))
+                return;
 
+        /* Queue the entry and raise the IPI if needed. */
         preempt_disable();
 
-        empty = llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
-        /* The list was empty, raise self-interrupt to start processing. */
-        if (empty)
-                arch_irq_work_raise();
+        llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
+
+        /*
+         * If the work is not "lazy" or the tick is stopped, raise the irq
+         * work interrupt (if supported by the arch), otherwise, just wait
+         * for the next tick.
+         */
+        if (!(work->flags & IRQ_WORK_LAZY) || tick_nohz_tick_stopped()) {
+                if (!this_cpu_cmpxchg(irq_work_raised, 0, 1))
+                        arch_irq_work_raise();
+        }
 
         preempt_enable();
 }
+EXPORT_SYMBOL_GPL(irq_work_queue);
 
-/*
- * Enqueue the irq_work @entry, returns true on success, failure when the
- * @entry was already enqueued by someone else.
- *
- * Can be re-enqueued while the callback is still in progress.
- */
-bool irq_work_queue(struct irq_work *work)
+bool irq_work_needs_cpu(void)
 {
-        if (!irq_work_claim(work)) {
-                /*
-                 * Already enqueued, can't do!
-                 */
+        struct llist_head *this_list;
+
+        this_list = &__get_cpu_var(irq_work_list);
+        if (llist_empty(this_list))
                 return false;
-        }
 
-        __irq_work_queue(work);
+        /* All work should have been flushed before going offline */
+        WARN_ON_ONCE(cpu_is_offline(smp_processor_id()));
+
         return true;
 }
-EXPORT_SYMBOL_GPL(irq_work_queue);
 
-/*
- * Run the irq_work entries on this cpu. Requires to be ran from hardirq
- * context with local IRQs disabled.
- */
-void irq_work_run(void)
+static void __irq_work_run(void)
 {
+        unsigned long flags;
         struct irq_work *work;
         struct llist_head *this_list;
         struct llist_node *llnode;
 
+
+        /*
+         * Reset the "raised" state right before we check the list because
+         * an NMI may enqueue after we find the list empty from the runner.
+         */
+        __this_cpu_write(irq_work_raised, 0);
+        barrier();
+
         this_list = &__get_cpu_var(irq_work_list);
         if (llist_empty(this_list))
                 return;
 
-        BUG_ON(!in_irq());
         BUG_ON(!irqs_disabled());
 
         llnode = llist_del_all(this_list);
@@ -119,16 +130,31 @@ void irq_work_run(void)
                 /*
                  * Clear the PENDING bit, after this point the @work
                  * can be re-used.
+                 * Make it immediately visible so that other CPUs trying
+                 * to claim that work don't rely on us to handle their data
+                 * while we are in the middle of the func.
                  */
-                work->flags = IRQ_WORK_BUSY;
+                flags = work->flags & ~IRQ_WORK_PENDING;
+                xchg(&work->flags, flags);
+
                 work->func(work);
                 /*
                  * Clear the BUSY bit and return to the free state if
                  * no-one else claimed it meanwhile.
                  */
-                (void)cmpxchg(&work->flags, IRQ_WORK_BUSY, 0);
+                (void)cmpxchg(&work->flags, flags, flags & ~IRQ_WORK_BUSY);
         }
 }
+
+/*
+ * Run the irq_work entries on this cpu. Requires to be ran from hardirq
+ * context with local IRQs disabled.
+ */
+void irq_work_run(void)
+{
+        BUG_ON(!in_irq());
+        __irq_work_run();
+}
 EXPORT_SYMBOL_GPL(irq_work_run);
 
 /*
@@ -143,3 +169,35 @@ void irq_work_sync(struct irq_work *work)
                 cpu_relax();
 }
 EXPORT_SYMBOL_GPL(irq_work_sync);
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int irq_work_cpu_notify(struct notifier_block *self,
+                               unsigned long action, void *hcpu)
+{
+        long cpu = (long)hcpu;
+
+        switch (action) {
+        case CPU_DYING:
+                /* Called from stop_machine */
+                if (WARN_ON_ONCE(cpu != smp_processor_id()))
+                        break;
+                __irq_work_run();
+                break;
+        default:
+                break;
+        }
+        return NOTIFY_OK;
+}
+
+static struct notifier_block cpu_notify;
+
+static __init int irq_work_init_cpu_notifier(void)
+{
+        cpu_notify.notifier_call = irq_work_cpu_notify;
+        cpu_notify.priority = 0;
+        register_cpu_notifier(&cpu_notify);
+        return 0;
+}
+device_initcall(irq_work_init_cpu_notifier);
+
+#endif /* CONFIG_HOTPLUG_CPU */
diff --git a/kernel/printk.c b/kernel/printk.c
index 267ce780abe8..f24633afa46a 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -42,6 +42,7 @@
 #include <linux/notifier.h>
 #include <linux/rculist.h>
 #include <linux/poll.h>
+#include <linux/irq_work.h>
 
 #include <asm/uaccess.h>
 
@@ -1959,30 +1960,32 @@ int is_console_locked(void)
 static DEFINE_PER_CPU(int, printk_pending);
 static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
 
-void printk_tick(void)
+static void wake_up_klogd_work_func(struct irq_work *irq_work)
 {
-        if (__this_cpu_read(printk_pending)) {
-                int pending = __this_cpu_xchg(printk_pending, 0);
-                if (pending & PRINTK_PENDING_SCHED) {
-                        char *buf = __get_cpu_var(printk_sched_buf);
-                        printk(KERN_WARNING "[sched_delayed] %s", buf);
-                }
-                if (pending & PRINTK_PENDING_WAKEUP)
-                        wake_up_interruptible(&log_wait);
+        int pending = __this_cpu_xchg(printk_pending, 0);
+
+        if (pending & PRINTK_PENDING_SCHED) {
+                char *buf = __get_cpu_var(printk_sched_buf);
+                printk(KERN_WARNING "[sched_delayed] %s", buf);
         }
-}
 
-int printk_needs_cpu(int cpu)
-{
-        if (cpu_is_offline(cpu))
-                printk_tick();
-        return __this_cpu_read(printk_pending);
+        if (pending & PRINTK_PENDING_WAKEUP)
+                wake_up_interruptible(&log_wait);
 }
 
+static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = {
+        .func = wake_up_klogd_work_func,
+        .flags = IRQ_WORK_LAZY,
+};
+
 void wake_up_klogd(void)
 {
-        if (waitqueue_active(&log_wait))
+        preempt_disable();
+        if (waitqueue_active(&log_wait)) {
                 this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
+                irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+        }
+        preempt_enable();
 }
 
 static void console_cont_flush(char *text, size_t size)
@@ -2462,6 +2465,7 @@ int printk_sched(const char *fmt, ...)
         va_end(args);
 
         __this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
+        irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
         local_irq_restore(flags);
 
         return r;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d58e552d9fd1..fb8e5e469d1c 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -20,6 +20,7 @@
 #include <linux/profile.h>
 #include <linux/sched.h>
 #include <linux/module.h>
+#include <linux/irq_work.h>
 
 #include <asm/irq_regs.h>
 
@@ -28,7 +29,7 @@
 /*
  * Per cpu nohz control structure
  */
-static DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched);
+DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched);
 
 /*
  * The time, when the last jiffy update happened. Protected by jiffies_lock.
@@ -331,8 +332,8 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
                 time_delta = timekeeping_max_deferment();
         } while (read_seqretry(&jiffies_lock, seq));
 
-        if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) ||
-            arch_needs_cpu(cpu)) {
+        if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
+            arch_needs_cpu(cpu) || irq_work_needs_cpu()) {
                 next_jiffies = last_jiffies + 1;
                 delta_jiffies = 1;
         } else {
diff --git a/kernel/timer.c b/kernel/timer.c
index 367d00858482..ff3b5165737b 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1351,7 +1351,6 @@ void update_process_times(int user_tick)
         account_process_tick(p, user_tick);
         run_local_timers();
         rcu_check_callbacks(cpu, user_tick);
-        printk_tick();
 #ifdef CONFIG_IRQ_WORK
         if (in_irq())
                 irq_work_run();