Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - a few misc things

 - kexec updates

 - DMA-mapping updates to better support networking DMA operations

 - IPC updates

 - various MM changes to improve DAX fault handling

 - lots of radix-tree changes, mainly to the test suite. All leading up
   to reimplementing the IDA/IDR code to be a wrapper layer over the
   radix-tree. However the final trigger-pulling patch is held off for
   4.11.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
  radix tree test suite: delete unused rcupdate.c
  radix tree test suite: add new tag check
  radix-tree: ensure counts are initialised
  radix tree test suite: cache recently freed objects
  radix tree test suite: add some more functionality
  idr: reduce the number of bits per level from 8 to 6
  rxrpc: abstract away knowledge of IDR internals
  tpm: use idr_find(), not idr_find_slowpath()
  idr: add ida_is_empty
  radix tree test suite: check multiorder iteration
  radix-tree: fix replacement for multiorder entries
  radix-tree: add radix_tree_split_preload()
  radix-tree: add radix_tree_split
  radix-tree: add radix_tree_join
  radix-tree: delete radix_tree_range_tag_if_tagged()
  radix-tree: delete radix_tree_locate_item()
  radix-tree: improve multiorder iterators
  btrfs: fix race in btrfs_free_dummy_fs_info()
  radix-tree: improve dump output
  radix-tree: make radix_tree_find_next_bit more useful
  ...

1 files changed, 15 insertions, 255 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 9acb29f280ec..d4b0fa01cae3 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -24,32 +24,14 @@
 
 #include <asm/irq_regs.h>
 #include <linux/kvm_para.h>
-#include <linux/perf_event.h>
 #include <linux/kthread.h>
 
-/*
- * The run state of the lockup detectors is controlled by the content of the
- * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
- * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
- *
- * 'watchdog_user_enabled', 'nmi_watchdog_enabled' and 'soft_watchdog_enabled'
- * are variables that are only used as an 'interface' between the parameters
- * in /proc/sys/kernel and the internal state bits in 'watchdog_enabled'. The
- * 'watchdog_thresh' variable is handled differently because its value is not
- * boolean, and the lockup detectors are 'suspended' while 'watchdog_thresh'
- * is equal zero.
- */
-#define NMI_WATCHDOG_ENABLED_BIT   0
-#define SOFT_WATCHDOG_ENABLED_BIT  1
-#define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
-#define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
-
 static DEFINE_MUTEX(watchdog_proc_mutex);
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
+#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
+unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
 #else
-static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
+unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
 #endif
 int __read_mostly nmi_watchdog_enabled;
 int __read_mostly soft_watchdog_enabled;
@@ -59,9 +41,6 @@ int __read_mostly watchdog_thresh = 10;
 #ifdef CONFIG_SMP
 int __read_mostly sysctl_softlockup_all_cpu_backtrace;
 int __read_mostly sysctl_hardlockup_all_cpu_backtrace;
-#else
-#define sysctl_softlockup_all_cpu_backtrace 0
-#define sysctl_hardlockup_all_cpu_backtrace 0
 #endif
 static struct cpumask watchdog_cpumask __read_mostly;
 unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
@@ -100,50 +79,9 @@ static DEFINE_PER_CPU(bool, soft_watchdog_warn);
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
 static DEFINE_PER_CPU(unsigned long, soft_lockup_hrtimer_cnt);
 static DEFINE_PER_CPU(struct task_struct *, softlockup_task_ptr_saved);
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-static DEFINE_PER_CPU(bool, hard_watchdog_warn);
-static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
-static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
-#endif
 static unsigned long soft_lockup_nmi_warn;
 
-/* boot commands */
-/*
- * Should we panic when a soft-lockup or hard-lockup occurs:
- */
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-unsigned int __read_mostly hardlockup_panic =
-                        CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
-static unsigned long hardlockup_allcpu_dumped;
-/*
- * We may not want to enable hard lockup detection by default in all cases,
- * for example when running the kernel as a guest on a hypervisor. In these
- * cases this function can be called to disable hard lockup detection. This
- * function should only be executed once by the boot processor before the
- * kernel command line parameters are parsed, because otherwise it is not
- * possible to override this in hardlockup_panic_setup().
- */
-void hardlockup_detector_disable(void)
-{
-        watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-}
-
-static int __init hardlockup_panic_setup(char *str)
-{
-        if (!strncmp(str, "panic", 5))
-                hardlockup_panic = 1;
-        else if (!strncmp(str, "nopanic", 7))
-                hardlockup_panic = 0;
-        else if (!strncmp(str, "0", 1))
-                watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-        else if (!strncmp(str, "1", 1))
-                watchdog_enabled |= NMI_WATCHDOG_ENABLED;
-        return 1;
-}
-__setup("nmi_watchdog=", hardlockup_panic_setup);
-#endif
-
 unsigned int __read_mostly softlockup_panic =
                         CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
 
@@ -264,32 +202,14 @@ void touch_all_softlockup_watchdogs(void)
         wq_watchdog_touch(-1);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-void touch_nmi_watchdog(void)
-{
-        /*
-         * Using __raw here because some code paths have
-         * preemption enabled.  If preemption is enabled
-         * then interrupts should be enabled too, in which
-         * case we shouldn't have to worry about the watchdog
-         * going off.
-         */
-        raw_cpu_write(watchdog_nmi_touch, true);
-        touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-
-#endif
-
 void touch_softlockup_watchdog_sync(void)
 {
         __this_cpu_write(softlockup_touch_sync, true);
         __this_cpu_write(watchdog_touch_ts, 0);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
 /* watchdog detector functions */
-static bool is_hardlockup(void)
+bool is_hardlockup(void)
 {
         unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
 
@@ -299,7 +219,6 @@ static bool is_hardlockup(void)
         __this_cpu_write(hrtimer_interrupts_saved, hrint);
         return false;
 }
-#endif
 
 static int is_softlockup(unsigned long touch_ts)
 {
@@ -313,78 +232,22 @@ static int is_softlockup(unsigned long touch_ts)
         return 0;
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-
-static struct perf_event_attr wd_hw_attr = {
-        .type           = PERF_TYPE_HARDWARE,
-        .config         = PERF_COUNT_HW_CPU_CYCLES,
-        .size           = sizeof(struct perf_event_attr),
-        .pinned         = 1,
-        .disabled       = 1,
-};
-
-/* Callback function for perf event subsystem */
-static void watchdog_overflow_callback(struct perf_event *event,
-                 struct perf_sample_data *data,
-                 struct pt_regs *regs)
-{
-        /* Ensure the watchdog never gets throttled */
-        event->hw.interrupts = 0;
-
-        if (__this_cpu_read(watchdog_nmi_touch) == true) {
-                __this_cpu_write(watchdog_nmi_touch, false);
-                return;
-        }
-
-        /* check for a hardlockup
-         * This is done by making sure our timer interrupt
-         * is incrementing.  The timer interrupt should have
-         * fired multiple times before we overflow'd.  If it hasn't
-         * then this is a good indication the cpu is stuck
-         */
-        if (is_hardlockup()) {
-                int this_cpu = smp_processor_id();
-                struct pt_regs *regs = get_irq_regs();
-
-                /* only print hardlockups once */
-                if (__this_cpu_read(hard_watchdog_warn) == true)
-                        return;
-
-                pr_emerg("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
-                print_modules();
-                print_irqtrace_events(current);
-                if (regs)
-                        show_regs(regs);
-                else
-                        dump_stack();
-
-                /*
-                 * Perform all-CPU dump only once to avoid multiple hardlockups
-                 * generating interleaving traces
-                 */
-                if (sysctl_hardlockup_all_cpu_backtrace &&
-                                !test_and_set_bit(0, &hardlockup_allcpu_dumped))
-                        trigger_allbutself_cpu_backtrace();
-
-                if (hardlockup_panic)
-                        nmi_panic(regs, "Hard LOCKUP");
-
-                __this_cpu_write(hard_watchdog_warn, true);
-                return;
-        }
-
-        __this_cpu_write(hard_watchdog_warn, false);
-        return;
-}
-#endif /* CONFIG_HARDLOCKUP_DETECTOR */
-
 static void watchdog_interrupt_count(void)
 {
         __this_cpu_inc(hrtimer_interrupts);
 }
 
-static int watchdog_nmi_enable(unsigned int cpu);
-static void watchdog_nmi_disable(unsigned int cpu);
+/*
+ * These two functions are mostly architecture specific
+ * defining them as weak here.
+ */
+int __weak watchdog_nmi_enable(unsigned int cpu)
+{
+        return 0;
+}
+void __weak watchdog_nmi_disable(unsigned int cpu)
+{
+}
 
 static int watchdog_enable_all_cpus(void);
 static void watchdog_disable_all_cpus(void);
@@ -577,109 +440,6 @@ static void watchdog(unsigned int cpu)
                 watchdog_nmi_disable(cpu);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-/*
- * People like the simple clean cpu node info on boot.
- * Reduce the watchdog noise by only printing messages
- * that are different from what cpu0 displayed.
- */
-static unsigned long cpu0_err;
-
-static int watchdog_nmi_enable(unsigned int cpu)
-{
-        struct perf_event_attr *wd_attr;
-        struct perf_event *event = per_cpu(watchdog_ev, cpu);
-
-        /* nothing to do if the hard lockup detector is disabled */
-        if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
-                goto out;
-
-        /* is it already setup and enabled? */
-        if (event && event->state > PERF_EVENT_STATE_OFF)
-                goto out;
-
-        /* it is setup but not enabled */
-        if (event != NULL)
-                goto out_enable;
-
-        wd_attr = &wd_hw_attr;
-        wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
-
-        /* Try to register using hardware perf events */
-        event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
-
-        /* save cpu0 error for future comparision */
-        if (cpu == 0 && IS_ERR(event))
-                cpu0_err = PTR_ERR(event);
-
-        if (!IS_ERR(event)) {
-                /* only print for cpu0 or different than cpu0 */
-                if (cpu == 0 || cpu0_err)
-                        pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
-                goto out_save;
-        }
-
-        /*
-         * Disable the hard lockup detector if _any_ CPU fails to set up
-         * set up the hardware perf event. The watchdog() function checks
-         * the NMI_WATCHDOG_ENABLED bit periodically.
-         *
-         * The barriers are for syncing up watchdog_enabled across all the
-         * cpus, as clear_bit() does not use barriers.
-         */
-        smp_mb__before_atomic();
-        clear_bit(NMI_WATCHDOG_ENABLED_BIT, &watchdog_enabled);
-        smp_mb__after_atomic();
-
-        /* skip displaying the same error again */
-        if (cpu > 0 && (PTR_ERR(event) == cpu0_err))
-                return PTR_ERR(event);
-
-        /* vary the KERN level based on the returned errno */
-        if (PTR_ERR(event) == -EOPNOTSUPP)
-                pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
-        else if (PTR_ERR(event) == -ENOENT)
-                pr_warn("disabled (cpu%i): hardware events not enabled\n",
-                         cpu);
-        else
-                pr_err("disabled (cpu%i): unable to create perf event: %ld\n",
-                        cpu, PTR_ERR(event));
-
-        pr_info("Shutting down hard lockup detector on all cpus\n");
-
-        return PTR_ERR(event);
-
-        /* success path */
-out_save:
-        per_cpu(watchdog_ev, cpu) = event;
-out_enable:
-        perf_event_enable(per_cpu(watchdog_ev, cpu));
-out:
-        return 0;
-}
-
-static void watchdog_nmi_disable(unsigned int cpu)
-{
-        struct perf_event *event = per_cpu(watchdog_ev, cpu);
-
-        if (event) {
-                perf_event_disable(event);
-                per_cpu(watchdog_ev, cpu) = NULL;
-
-                /* should be in cleanup, but blocks oprofile */
-                perf_event_release_kernel(event);
-        }
-        if (cpu == 0) {
-                /* watchdog_nmi_enable() expects this to be zero initially. */
-                cpu0_err = 0;
-        }
-}
-
-#else
-static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
-static void watchdog_nmi_disable(unsigned int cpu) { return; }
-#endif /* CONFIG_HARDLOCKUP_DETECTOR */
-
 static struct smp_hotplug_thread watchdog_threads = {
         .store                  = &softlockup_watchdog,
         .thread_should_run      = watchdog_should_run,