Move kernel/profile.c to instrumentation/.
Signed-off-by: Mathieu Desnoyers <[email protected]>
CC: Ingo Molnar <[email protected]>
CC: William L. Irwin <[email protected]>
CC: Arjan van de Ven <[email protected]>
---
instrumentation/Makefile | 2
instrumentation/profile.c | 597 ++++++++++++++++++++++++++++++++++++++++++++++
kernel/Makefile | 2
kernel/profile.c | 597 ----------------------------------------------
4 files changed, 600 insertions(+), 598 deletions(-)
Index: linux-2.6-lttng.stable/instrumentation/Makefile
===================================================================
--- linux-2.6-lttng.stable.orig/instrumentation/Makefile 2007-10-29 09:52:09.000000000 -0400
+++ linux-2.6-lttng.stable/instrumentation/Makefile 2007-10-29 09:52:30.000000000 -0400
@@ -2,5 +2,7 @@
# Makefile for the linux kernel instrumentation
#
+obj-y += profile.o
+
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_MARKERS) += marker.o
Index: linux-2.6-lttng.stable/instrumentation/profile.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng.stable/instrumentation/profile.c 2007-10-29 09:52:13.000000000 -0400
@@ -0,0 +1,597 @@
+/*
+ * linux/kernel/profile.c
+ * Simple profiling. Manages a direct-mapped profile hit count buffer,
+ * with configurable resolution, support for restricting the cpus on
+ * which profiling is done, and switching between cpu time and
+ * schedule() calls via kernel command line parameters passed at boot.
+ *
+ * Scheduler profiling support, Arjan van de Ven and Ingo Molnar,
+ * Red Hat, July 2004
+ * Consolidation of architecture support code for profiling,
+ * William Irwin, Oracle, July 2004
+ * Amortized hit count accounting via per-cpu open-addressed hashtables
+ * to resolve timer interrupt livelocks, William Irwin, Oracle, 2004
+ */
+
+#include <linux/module.h>
+#include <linux/profile.h>
+#include <linux/bootmem.h>
+#include <linux/notifier.h>
+#include <linux/mm.h>
+#include <linux/cpumask.h>
+#include <linux/cpu.h>
+#include <linux/profile.h>
+#include <linux/highmem.h>
+#include <linux/mutex.h>
+#include <asm/sections.h>
+#include <asm/semaphore.h>
+#include <asm/irq_regs.h>
+#include <asm/ptrace.h>
+
+struct profile_hit {
+ u32 pc, hits;
+};
+#define PROFILE_GRPSHIFT 3
+#define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT)
+#define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit))
+#define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ)
+
+/* Oprofile timer tick hook */
+static int (*timer_hook)(struct pt_regs *) __read_mostly;
+
+static atomic_t *prof_buffer;
+static unsigned long prof_len, prof_shift;
+
+int prof_on __read_mostly;
+EXPORT_SYMBOL_GPL(prof_on);
+
+static cpumask_t prof_cpu_mask = CPU_MASK_ALL;
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits);
+static DEFINE_PER_CPU(int, cpu_profile_flip);
+static DEFINE_MUTEX(profile_flip_mutex);
+#endif /* CONFIG_SMP */
+
+static int __init profile_setup(char * str)
+{
+ static char __initdata schedstr[] = "schedule";
+ static char __initdata sleepstr[] = "sleep";
+ static char __initdata kvmstr[] = "kvm";
+ int par;
+
+ if (!strncmp(str, sleepstr, strlen(sleepstr))) {
+ prof_on = SLEEP_PROFILING;
+ if (str[strlen(sleepstr)] == ',')
+ str += strlen(sleepstr) + 1;
+ if (get_option(&str, &par))
+ prof_shift = par;
+ printk(KERN_INFO
+ "kernel sleep profiling enabled (shift: %ld)\n",
+ prof_shift);
+ } else if (!strncmp(str, schedstr, strlen(schedstr))) {
+ prof_on = SCHED_PROFILING;
+ if (str[strlen(schedstr)] == ',')
+ str += strlen(schedstr) + 1;
+ if (get_option(&str, &par))
+ prof_shift = par;
+ printk(KERN_INFO
+ "kernel schedule profiling enabled (shift: %ld)\n",
+ prof_shift);
+ } else if (!strncmp(str, kvmstr, strlen(kvmstr))) {
+ prof_on = KVM_PROFILING;
+ if (str[strlen(kvmstr)] == ',')
+ str += strlen(kvmstr) + 1;
+ if (get_option(&str, &par))
+ prof_shift = par;
+ printk(KERN_INFO
+ "kernel KVM profiling enabled (shift: %ld)\n",
+ prof_shift);
+ } else if (get_option(&str, &par)) {
+ prof_shift = par;
+ prof_on = CPU_PROFILING;
+ printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n",
+ prof_shift);
+ }
+ return 1;
+}
+__setup("profile=", profile_setup);
+
+
+void __init profile_init(void)
+{
+ if (!prof_on)
+ return;
+
+ /* only text is profiled */
+ prof_len = (_etext - _stext) >> prof_shift;
+ prof_buffer = alloc_bootmem(prof_len*sizeof(atomic_t));
+}
+
+/* Profile event notifications */
+
+#ifdef CONFIG_PROFILING
+
+static BLOCKING_NOTIFIER_HEAD(task_exit_notifier);
+static ATOMIC_NOTIFIER_HEAD(task_free_notifier);
+static BLOCKING_NOTIFIER_HEAD(munmap_notifier);
+
+void profile_task_exit(struct task_struct * task)
+{
+ blocking_notifier_call_chain(&task_exit_notifier, 0, task);
+}
+
+int profile_handoff_task(struct task_struct * task)
+{
+ int ret;
+ ret = atomic_notifier_call_chain(&task_free_notifier, 0, task);
+ return (ret == NOTIFY_OK) ? 1 : 0;
+}
+
+void profile_munmap(unsigned long addr)
+{
+ blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr);
+}
+
+int task_handoff_register(struct notifier_block * n)
+{
+ return atomic_notifier_chain_register(&task_free_notifier, n);
+}
+
+int task_handoff_unregister(struct notifier_block * n)
+{
+ return atomic_notifier_chain_unregister(&task_free_notifier, n);
+}
+
+int profile_event_register(enum profile_type type, struct notifier_block * n)
+{
+ int err = -EINVAL;
+
+ switch (type) {
+ case PROFILE_TASK_EXIT:
+ err = blocking_notifier_chain_register(
+ &task_exit_notifier, n);
+ break;
+ case PROFILE_MUNMAP:
+ err = blocking_notifier_chain_register(
+ &munmap_notifier, n);
+ break;
+ }
+
+ return err;
+}
+
+
+int profile_event_unregister(enum profile_type type, struct notifier_block * n)
+{
+ int err = -EINVAL;
+
+ switch (type) {
+ case PROFILE_TASK_EXIT:
+ err = blocking_notifier_chain_unregister(
+ &task_exit_notifier, n);
+ break;
+ case PROFILE_MUNMAP:
+ err = blocking_notifier_chain_unregister(
+ &munmap_notifier, n);
+ break;
+ }
+
+ return err;
+}
+
+int register_timer_hook(int (*hook)(struct pt_regs *))
+{
+ if (timer_hook)
+ return -EBUSY;
+ timer_hook = hook;
+ return 0;
+}
+
+void unregister_timer_hook(int (*hook)(struct pt_regs *))
+{
+ WARN_ON(hook != timer_hook);
+ timer_hook = NULL;
+ /* make sure all CPUs see the NULL hook */
+ synchronize_sched(); /* Allow ongoing interrupts to complete. */
+}
+
+EXPORT_SYMBOL_GPL(register_timer_hook);
+EXPORT_SYMBOL_GPL(unregister_timer_hook);
+EXPORT_SYMBOL_GPL(task_handoff_register);
+EXPORT_SYMBOL_GPL(task_handoff_unregister);
+EXPORT_SYMBOL_GPL(profile_event_register);
+EXPORT_SYMBOL_GPL(profile_event_unregister);
+
+#endif /* CONFIG_PROFILING */
+
+
+#ifdef CONFIG_SMP
+/*
+ * Each cpu has a pair of open-addressed hashtables for pending
+ * profile hits. read_profile() IPI's all cpus to request them
+ * to flip buffers and flushes their contents to prof_buffer itself.
+ * Flip requests are serialized by the profile_flip_mutex. The sole
+ * use of having a second hashtable is for avoiding cacheline
+ * contention that would otherwise happen during flushes of pending
+ * profile hits required for the accuracy of reported profile hits
+ * and so resurrect the interrupt livelock issue.
+ *
+ * The open-addressed hashtables are indexed by profile buffer slot
+ * and hold the number of pending hits to that profile buffer slot on
+ * a cpu in an entry. When the hashtable overflows, all pending hits
+ * are accounted to their corresponding profile buffer slots with
+ * atomic_add() and the hashtable emptied. As numerous pending hits
+ * may be accounted to a profile buffer slot in a hashtable entry,
+ * this amortizes a number of atomic profile buffer increments likely
+ * to be far larger than the number of entries in the hashtable,
+ * particularly given that the number of distinct profile buffer
+ * positions to which hits are accounted during short intervals (e.g.
+ * several seconds) is usually very small. Exclusion from buffer
+ * flipping is provided by interrupt disablement (note that for
+ * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from
+ * process context).
+ * The hash function is meant to be lightweight as opposed to strong,
+ * and was vaguely inspired by ppc64 firmware-supported inverted
+ * pagetable hash functions, but uses a full hashtable full of finite
+ * collision chains, not just pairs of them.
+ *
+ * -- wli
+ */
+static void __profile_flip_buffers(void *unused)
+{
+ int cpu = smp_processor_id();
+
+ per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu);
+}
+
+static void profile_flip_buffers(void)
+{
+ int i, j, cpu;
+
+ mutex_lock(&profile_flip_mutex);
+ j = per_cpu(cpu_profile_flip, get_cpu());
+ put_cpu();
+ on_each_cpu(__profile_flip_buffers, NULL, 0, 1);
+ for_each_online_cpu(cpu) {
+ struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j];
+ for (i = 0; i < NR_PROFILE_HIT; ++i) {
+ if (!hits[i].hits) {
+ if (hits[i].pc)
+ hits[i].pc = 0;
+ continue;
+ }
+ atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]);
+ hits[i].hits = hits[i].pc = 0;
+ }
+ }
+ mutex_unlock(&profile_flip_mutex);
+}
+
+static void profile_discard_flip_buffers(void)
+{
+ int i, cpu;
+
+ mutex_lock(&profile_flip_mutex);
+ i = per_cpu(cpu_profile_flip, get_cpu());
+ put_cpu();
+ on_each_cpu(__profile_flip_buffers, NULL, 0, 1);
+ for_each_online_cpu(cpu) {
+ struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i];
+ memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit));
+ }
+ mutex_unlock(&profile_flip_mutex);
+}
+
+void profile_hits(int type, void *__pc, unsigned int nr_hits)
+{
+ unsigned long primary, secondary, flags, pc = (unsigned long)__pc;
+ int i, j, cpu;
+ struct profile_hit *hits;
+
+ if (prof_on != type || !prof_buffer)
+ return;
+ pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1);
+ i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT;
+ secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT;
+ cpu = get_cpu();
+ hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)];
+ if (!hits) {
+ put_cpu();
+ return;
+ }
+ /*
+ * We buffer the global profiler buffer into a per-CPU
+ * queue and thus reduce the number of global (and possibly
+ * NUMA-alien) accesses. The write-queue is self-coalescing:
+ */
+ local_irq_save(flags);
+ do {
+ for (j = 0; j < PROFILE_GRPSZ; ++j) {
+ if (hits[i + j].pc == pc) {
+ hits[i + j].hits += nr_hits;
+ goto out;
+ } else if (!hits[i + j].hits) {
+ hits[i + j].pc = pc;
+ hits[i + j].hits = nr_hits;
+ goto out;
+ }
+ }
+ i = (i + secondary) & (NR_PROFILE_HIT - 1);
+ } while (i != primary);
+
+ /*
+ * Add the current hit(s) and flush the write-queue out
+ * to the global buffer:
+ */
+ atomic_add(nr_hits, &prof_buffer[pc]);
+ for (i = 0; i < NR_PROFILE_HIT; ++i) {
+ atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]);
+ hits[i].pc = hits[i].hits = 0;
+ }
+out:
+ local_irq_restore(flags);
+ put_cpu();
+}
+
+static int __devinit profile_cpu_callback(struct notifier_block *info,
+ unsigned long action, void *__cpu)
+{
+ int node, cpu = (unsigned long)__cpu;
+ struct page *page;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ node = cpu_to_node(cpu);
+ per_cpu(cpu_profile_flip, cpu) = 0;
+ if (!per_cpu(cpu_profile_hits, cpu)[1]) {
+ page = alloc_pages_node(node,
+ GFP_KERNEL | __GFP_ZERO,
+ 0);
+ if (!page)
+ return NOTIFY_BAD;
+ per_cpu(cpu_profile_hits, cpu)[1] = page_address(page);
+ }
+ if (!per_cpu(cpu_profile_hits, cpu)[0]) {
+ page = alloc_pages_node(node,
+ GFP_KERNEL | __GFP_ZERO,
+ 0);
+ if (!page)
+ goto out_free;
+ per_cpu(cpu_profile_hits, cpu)[0] = page_address(page);
+ }
+ break;
+ out_free:
+ page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
+ per_cpu(cpu_profile_hits, cpu)[1] = NULL;
+ __free_page(page);
+ return NOTIFY_BAD;
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ cpu_set(cpu, prof_cpu_mask);
+ break;
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ cpu_clear(cpu, prof_cpu_mask);
+ if (per_cpu(cpu_profile_hits, cpu)[0]) {
+ page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
+ per_cpu(cpu_profile_hits, cpu)[0] = NULL;
+ __free_page(page);
+ }
+ if (per_cpu(cpu_profile_hits, cpu)[1]) {
+ page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
+ per_cpu(cpu_profile_hits, cpu)[1] = NULL;
+ __free_page(page);
+ }
+ break;
+ }
+ return NOTIFY_OK;
+}
+#else /* !CONFIG_SMP */
+#define profile_flip_buffers() do { } while (0)
+#define profile_discard_flip_buffers() do { } while (0)
+#define profile_cpu_callback NULL
+
+void profile_hits(int type, void *__pc, unsigned int nr_hits)
+{
+ unsigned long pc;
+
+ if (prof_on != type || !prof_buffer)
+ return;
+ pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift;
+ atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]);
+}
+#endif /* !CONFIG_SMP */
+
+EXPORT_SYMBOL_GPL(profile_hits);
+
+void profile_tick(int type)
+{
+ struct pt_regs *regs = get_irq_regs();
+
+ if (type == CPU_PROFILING && timer_hook)
+ timer_hook(regs);
+ if (!user_mode(regs) && cpu_isset(smp_processor_id(), prof_cpu_mask))
+ profile_hit(type, (void *)profile_pc(regs));
+}
+
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+#include <asm/uaccess.h>
+#include <asm/ptrace.h>
+
+static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len = cpumask_scnprintf(page, count, *(cpumask_t *)data);
+ if (count - len < 2)
+ return -EINVAL;
+ len += sprintf(page + len, "\n");
+ return len;
+}
+
+static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffer,
+ unsigned long count, void *data)
+{
+ cpumask_t *mask = (cpumask_t *)data;
+ unsigned long full_count = count, err;
+ cpumask_t new_value;
+
+ err = cpumask_parse_user(buffer, count, new_value);
+ if (err)
+ return err;
+
+ *mask = new_value;
+ return full_count;
+}
+
+void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir)
+{
+ struct proc_dir_entry *entry;
+
+ /* create /proc/irq/prof_cpu_mask */
+ if (!(entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir)))
+ return;
+ entry->data = (void *)&prof_cpu_mask;
+ entry->read_proc = prof_cpu_mask_read_proc;
+ entry->write_proc = prof_cpu_mask_write_proc;
+}
+
+/*
+ * This function accesses profiling information. The returned data is
+ * binary: the sampling step and the actual contents of the profile
+ * buffer. Use of the program readprofile is recommended in order to
+ * get meaningful info out of these data.
+ */
+static ssize_t
+read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+ unsigned long p = *ppos;
+ ssize_t read;
+ char * pnt;
+ unsigned int sample_step = 1 << prof_shift;
+
+ profile_flip_buffers();
+ if (p >= (prof_len+1)*sizeof(unsigned int))
+ return 0;
+ if (count > (prof_len+1)*sizeof(unsigned int) - p)
+ count = (prof_len+1)*sizeof(unsigned int) - p;
+ read = 0;
+
+ while (p < sizeof(unsigned int) && count > 0) {
+ if (put_user(*((char *)(&sample_step)+p),buf))
+ return -EFAULT;
+ buf++; p++; count--; read++;
+ }
+ pnt = (char *)prof_buffer + p - sizeof(atomic_t);
+ if (copy_to_user(buf,(void *)pnt,count))
+ return -EFAULT;
+ read += count;
+ *ppos += read;
+ return read;
+}
+
+/*
+ * Writing to /proc/profile resets the counters
+ *
+ * Writing a 'profiling multiplier' value into it also re-sets the profiling
+ * interrupt frequency, on architectures that support this.
+ */
+static ssize_t write_profile(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+#ifdef CONFIG_SMP
+ extern int setup_profiling_timer (unsigned int multiplier);
+
+ if (count == sizeof(int)) {
+ unsigned int multiplier;
+
+ if (copy_from_user(&multiplier, buf, sizeof(int)))
+ return -EFAULT;
+
+ if (setup_profiling_timer(multiplier))
+ return -EINVAL;
+ }
+#endif
+ profile_discard_flip_buffers();
+ memset(prof_buffer, 0, prof_len * sizeof(atomic_t));
+ return count;
+}
+
+static const struct file_operations proc_profile_operations = {
+ .read = read_profile,
+ .write = write_profile,
+};
+
+#ifdef CONFIG_SMP
+static void __init profile_nop(void *unused)
+{
+}
+
+static int __init create_hash_tables(void)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ int node = cpu_to_node(cpu);
+ struct page *page;
+
+ page = alloc_pages_node(node,
+ GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
+ 0);
+ if (!page)
+ goto out_cleanup;
+ per_cpu(cpu_profile_hits, cpu)[1]
+ = (struct profile_hit *)page_address(page);
+ page = alloc_pages_node(node,
+ GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
+ 0);
+ if (!page)
+ goto out_cleanup;
+ per_cpu(cpu_profile_hits, cpu)[0]
+ = (struct profile_hit *)page_address(page);
+ }
+ return 0;
+out_cleanup:
+ prof_on = 0;
+ smp_mb();
+ on_each_cpu(profile_nop, NULL, 0, 1);
+ for_each_online_cpu(cpu) {
+ struct page *page;
+
+ if (per_cpu(cpu_profile_hits, cpu)[0]) {
+ page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
+ per_cpu(cpu_profile_hits, cpu)[0] = NULL;
+ __free_page(page);
+ }
+ if (per_cpu(cpu_profile_hits, cpu)[1]) {
+ page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
+ per_cpu(cpu_profile_hits, cpu)[1] = NULL;
+ __free_page(page);
+ }
+ }
+ return -1;
+}
+#else
+#define create_hash_tables() ({ 0; })
+#endif
+
+static int __init create_proc_profile(void)
+{
+ struct proc_dir_entry *entry;
+
+ if (!prof_on)
+ return 0;
+ if (create_hash_tables())
+ return -1;
+ if (!(entry = create_proc_entry("profile", S_IWUSR | S_IRUGO, NULL)))
+ return 0;
+ entry->proc_fops = &proc_profile_operations;
+ entry->size = (1+prof_len) * sizeof(atomic_t);
+ hotcpu_notifier(profile_cpu_callback, 0);
+ return 0;
+}
+module_init(create_proc_profile);
+#endif /* CONFIG_PROC_FS */
Index: linux-2.6-lttng.stable/kernel/Makefile
===================================================================
--- linux-2.6-lttng.stable.orig/kernel/Makefile 2007-10-29 09:51:51.000000000 -0400
+++ linux-2.6-lttng.stable/kernel/Makefile 2007-10-29 09:52:13.000000000 -0400
@@ -2,7 +2,7 @@
# Makefile for the linux kernel.
#
-obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
+obj-y = sched.o fork.o exec_domain.o panic.o printk.o \
exit.o itimer.o time.o softirq.o resource.o \
sysctl.o capability.o ptrace.o timer.o user.o user_namespace.o \
signal.o sys.o kmod.o workqueue.o pid.o \
Index: linux-2.6-lttng.stable/kernel/profile.c
===================================================================
--- linux-2.6-lttng.stable.orig/kernel/profile.c 2007-10-29 09:51:06.000000000 -0400
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,597 +0,0 @@
-/*
- * linux/kernel/profile.c
- * Simple profiling. Manages a direct-mapped profile hit count buffer,
- * with configurable resolution, support for restricting the cpus on
- * which profiling is done, and switching between cpu time and
- * schedule() calls via kernel command line parameters passed at boot.
- *
- * Scheduler profiling support, Arjan van de Ven and Ingo Molnar,
- * Red Hat, July 2004
- * Consolidation of architecture support code for profiling,
- * William Irwin, Oracle, July 2004
- * Amortized hit count accounting via per-cpu open-addressed hashtables
- * to resolve timer interrupt livelocks, William Irwin, Oracle, 2004
- */
-
-#include <linux/module.h>
-#include <linux/profile.h>
-#include <linux/bootmem.h>
-#include <linux/notifier.h>
-#include <linux/mm.h>
-#include <linux/cpumask.h>
-#include <linux/cpu.h>
-#include <linux/profile.h>
-#include <linux/highmem.h>
-#include <linux/mutex.h>
-#include <asm/sections.h>
-#include <asm/semaphore.h>
-#include <asm/irq_regs.h>
-#include <asm/ptrace.h>
-
-struct profile_hit {
- u32 pc, hits;
-};
-#define PROFILE_GRPSHIFT 3
-#define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT)
-#define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit))
-#define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ)
-
-/* Oprofile timer tick hook */
-static int (*timer_hook)(struct pt_regs *) __read_mostly;
-
-static atomic_t *prof_buffer;
-static unsigned long prof_len, prof_shift;
-
-int prof_on __read_mostly;
-EXPORT_SYMBOL_GPL(prof_on);
-
-static cpumask_t prof_cpu_mask = CPU_MASK_ALL;
-#ifdef CONFIG_SMP
-static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits);
-static DEFINE_PER_CPU(int, cpu_profile_flip);
-static DEFINE_MUTEX(profile_flip_mutex);
-#endif /* CONFIG_SMP */
-
-static int __init profile_setup(char * str)
-{
- static char __initdata schedstr[] = "schedule";
- static char __initdata sleepstr[] = "sleep";
- static char __initdata kvmstr[] = "kvm";
- int par;
-
- if (!strncmp(str, sleepstr, strlen(sleepstr))) {
- prof_on = SLEEP_PROFILING;
- if (str[strlen(sleepstr)] == ',')
- str += strlen(sleepstr) + 1;
- if (get_option(&str, &par))
- prof_shift = par;
- printk(KERN_INFO
- "kernel sleep profiling enabled (shift: %ld)\n",
- prof_shift);
- } else if (!strncmp(str, schedstr, strlen(schedstr))) {
- prof_on = SCHED_PROFILING;
- if (str[strlen(schedstr)] == ',')
- str += strlen(schedstr) + 1;
- if (get_option(&str, &par))
- prof_shift = par;
- printk(KERN_INFO
- "kernel schedule profiling enabled (shift: %ld)\n",
- prof_shift);
- } else if (!strncmp(str, kvmstr, strlen(kvmstr))) {
- prof_on = KVM_PROFILING;
- if (str[strlen(kvmstr)] == ',')
- str += strlen(kvmstr) + 1;
- if (get_option(&str, &par))
- prof_shift = par;
- printk(KERN_INFO
- "kernel KVM profiling enabled (shift: %ld)\n",
- prof_shift);
- } else if (get_option(&str, &par)) {
- prof_shift = par;
- prof_on = CPU_PROFILING;
- printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n",
- prof_shift);
- }
- return 1;
-}
-__setup("profile=", profile_setup);
-
-
-void __init profile_init(void)
-{
- if (!prof_on)
- return;
-
- /* only text is profiled */
- prof_len = (_etext - _stext) >> prof_shift;
- prof_buffer = alloc_bootmem(prof_len*sizeof(atomic_t));
-}
-
-/* Profile event notifications */
-
-#ifdef CONFIG_PROFILING
-
-static BLOCKING_NOTIFIER_HEAD(task_exit_notifier);
-static ATOMIC_NOTIFIER_HEAD(task_free_notifier);
-static BLOCKING_NOTIFIER_HEAD(munmap_notifier);
-
-void profile_task_exit(struct task_struct * task)
-{
- blocking_notifier_call_chain(&task_exit_notifier, 0, task);
-}
-
-int profile_handoff_task(struct task_struct * task)
-{
- int ret;
- ret = atomic_notifier_call_chain(&task_free_notifier, 0, task);
- return (ret == NOTIFY_OK) ? 1 : 0;
-}
-
-void profile_munmap(unsigned long addr)
-{
- blocking_notifier_call_chain(&munmap_notifier, 0, (void *)addr);
-}
-
-int task_handoff_register(struct notifier_block * n)
-{
- return atomic_notifier_chain_register(&task_free_notifier, n);
-}
-
-int task_handoff_unregister(struct notifier_block * n)
-{
- return atomic_notifier_chain_unregister(&task_free_notifier, n);
-}
-
-int profile_event_register(enum profile_type type, struct notifier_block * n)
-{
- int err = -EINVAL;
-
- switch (type) {
- case PROFILE_TASK_EXIT:
- err = blocking_notifier_chain_register(
- &task_exit_notifier, n);
- break;
- case PROFILE_MUNMAP:
- err = blocking_notifier_chain_register(
- &munmap_notifier, n);
- break;
- }
-
- return err;
-}
-
-
-int profile_event_unregister(enum profile_type type, struct notifier_block * n)
-{
- int err = -EINVAL;
-
- switch (type) {
- case PROFILE_TASK_EXIT:
- err = blocking_notifier_chain_unregister(
- &task_exit_notifier, n);
- break;
- case PROFILE_MUNMAP:
- err = blocking_notifier_chain_unregister(
- &munmap_notifier, n);
- break;
- }
-
- return err;
-}
-
-int register_timer_hook(int (*hook)(struct pt_regs *))
-{
- if (timer_hook)
- return -EBUSY;
- timer_hook = hook;
- return 0;
-}
-
-void unregister_timer_hook(int (*hook)(struct pt_regs *))
-{
- WARN_ON(hook != timer_hook);
- timer_hook = NULL;
- /* make sure all CPUs see the NULL hook */
- synchronize_sched(); /* Allow ongoing interrupts to complete. */
-}
-
-EXPORT_SYMBOL_GPL(register_timer_hook);
-EXPORT_SYMBOL_GPL(unregister_timer_hook);
-EXPORT_SYMBOL_GPL(task_handoff_register);
-EXPORT_SYMBOL_GPL(task_handoff_unregister);
-EXPORT_SYMBOL_GPL(profile_event_register);
-EXPORT_SYMBOL_GPL(profile_event_unregister);
-
-#endif /* CONFIG_PROFILING */
-
-
-#ifdef CONFIG_SMP
-/*
- * Each cpu has a pair of open-addressed hashtables for pending
- * profile hits. read_profile() IPI's all cpus to request them
- * to flip buffers and flushes their contents to prof_buffer itself.
- * Flip requests are serialized by the profile_flip_mutex. The sole
- * use of having a second hashtable is for avoiding cacheline
- * contention that would otherwise happen during flushes of pending
- * profile hits required for the accuracy of reported profile hits
- * and so resurrect the interrupt livelock issue.
- *
- * The open-addressed hashtables are indexed by profile buffer slot
- * and hold the number of pending hits to that profile buffer slot on
- * a cpu in an entry. When the hashtable overflows, all pending hits
- * are accounted to their corresponding profile buffer slots with
- * atomic_add() and the hashtable emptied. As numerous pending hits
- * may be accounted to a profile buffer slot in a hashtable entry,
- * this amortizes a number of atomic profile buffer increments likely
- * to be far larger than the number of entries in the hashtable,
- * particularly given that the number of distinct profile buffer
- * positions to which hits are accounted during short intervals (e.g.
- * several seconds) is usually very small. Exclusion from buffer
- * flipping is provided by interrupt disablement (note that for
- * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from
- * process context).
- * The hash function is meant to be lightweight as opposed to strong,
- * and was vaguely inspired by ppc64 firmware-supported inverted
- * pagetable hash functions, but uses a full hashtable full of finite
- * collision chains, not just pairs of them.
- *
- * -- wli
- */
-static void __profile_flip_buffers(void *unused)
-{
- int cpu = smp_processor_id();
-
- per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu);
-}
-
-static void profile_flip_buffers(void)
-{
- int i, j, cpu;
-
- mutex_lock(&profile_flip_mutex);
- j = per_cpu(cpu_profile_flip, get_cpu());
- put_cpu();
- on_each_cpu(__profile_flip_buffers, NULL, 0, 1);
- for_each_online_cpu(cpu) {
- struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j];
- for (i = 0; i < NR_PROFILE_HIT; ++i) {
- if (!hits[i].hits) {
- if (hits[i].pc)
- hits[i].pc = 0;
- continue;
- }
- atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]);
- hits[i].hits = hits[i].pc = 0;
- }
- }
- mutex_unlock(&profile_flip_mutex);
-}
-
-static void profile_discard_flip_buffers(void)
-{
- int i, cpu;
-
- mutex_lock(&profile_flip_mutex);
- i = per_cpu(cpu_profile_flip, get_cpu());
- put_cpu();
- on_each_cpu(__profile_flip_buffers, NULL, 0, 1);
- for_each_online_cpu(cpu) {
- struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i];
- memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit));
- }
- mutex_unlock(&profile_flip_mutex);
-}
-
-void profile_hits(int type, void *__pc, unsigned int nr_hits)
-{
- unsigned long primary, secondary, flags, pc = (unsigned long)__pc;
- int i, j, cpu;
- struct profile_hit *hits;
-
- if (prof_on != type || !prof_buffer)
- return;
- pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1);
- i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT;
- secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT;
- cpu = get_cpu();
- hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)];
- if (!hits) {
- put_cpu();
- return;
- }
- /*
- * We buffer the global profiler buffer into a per-CPU
- * queue and thus reduce the number of global (and possibly
- * NUMA-alien) accesses. The write-queue is self-coalescing:
- */
- local_irq_save(flags);
- do {
- for (j = 0; j < PROFILE_GRPSZ; ++j) {
- if (hits[i + j].pc == pc) {
- hits[i + j].hits += nr_hits;
- goto out;
- } else if (!hits[i + j].hits) {
- hits[i + j].pc = pc;
- hits[i + j].hits = nr_hits;
- goto out;
- }
- }
- i = (i + secondary) & (NR_PROFILE_HIT - 1);
- } while (i != primary);
-
- /*
- * Add the current hit(s) and flush the write-queue out
- * to the global buffer:
- */
- atomic_add(nr_hits, &prof_buffer[pc]);
- for (i = 0; i < NR_PROFILE_HIT; ++i) {
- atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]);
- hits[i].pc = hits[i].hits = 0;
- }
-out:
- local_irq_restore(flags);
- put_cpu();
-}
-
-static int __devinit profile_cpu_callback(struct notifier_block *info,
- unsigned long action, void *__cpu)
-{
- int node, cpu = (unsigned long)__cpu;
- struct page *page;
-
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- node = cpu_to_node(cpu);
- per_cpu(cpu_profile_flip, cpu) = 0;
- if (!per_cpu(cpu_profile_hits, cpu)[1]) {
- page = alloc_pages_node(node,
- GFP_KERNEL | __GFP_ZERO,
- 0);
- if (!page)
- return NOTIFY_BAD;
- per_cpu(cpu_profile_hits, cpu)[1] = page_address(page);
- }
- if (!per_cpu(cpu_profile_hits, cpu)[0]) {
- page = alloc_pages_node(node,
- GFP_KERNEL | __GFP_ZERO,
- 0);
- if (!page)
- goto out_free;
- per_cpu(cpu_profile_hits, cpu)[0] = page_address(page);
- }
- break;
- out_free:
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
- per_cpu(cpu_profile_hits, cpu)[1] = NULL;
- __free_page(page);
- return NOTIFY_BAD;
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- cpu_set(cpu, prof_cpu_mask);
- break;
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- cpu_clear(cpu, prof_cpu_mask);
- if (per_cpu(cpu_profile_hits, cpu)[0]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
- per_cpu(cpu_profile_hits, cpu)[0] = NULL;
- __free_page(page);
- }
- if (per_cpu(cpu_profile_hits, cpu)[1]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
- per_cpu(cpu_profile_hits, cpu)[1] = NULL;
- __free_page(page);
- }
- break;
- }
- return NOTIFY_OK;
-}
-#else /* !CONFIG_SMP */
-#define profile_flip_buffers() do { } while (0)
-#define profile_discard_flip_buffers() do { } while (0)
-#define profile_cpu_callback NULL
-
-void profile_hits(int type, void *__pc, unsigned int nr_hits)
-{
- unsigned long pc;
-
- if (prof_on != type || !prof_buffer)
- return;
- pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift;
- atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]);
-}
-#endif /* !CONFIG_SMP */
-
-EXPORT_SYMBOL_GPL(profile_hits);
-
-void profile_tick(int type)
-{
- struct pt_regs *regs = get_irq_regs();
-
- if (type == CPU_PROFILING && timer_hook)
- timer_hook(regs);
- if (!user_mode(regs) && cpu_isset(smp_processor_id(), prof_cpu_mask))
- profile_hit(type, (void *)profile_pc(regs));
-}
-
-#ifdef CONFIG_PROC_FS
-#include <linux/proc_fs.h>
-#include <asm/uaccess.h>
-#include <asm/ptrace.h>
-
-static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
- int count, int *eof, void *data)
-{
- int len = cpumask_scnprintf(page, count, *(cpumask_t *)data);
- if (count - len < 2)
- return -EINVAL;
- len += sprintf(page + len, "\n");
- return len;
-}
-
-static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffer,
- unsigned long count, void *data)
-{
- cpumask_t *mask = (cpumask_t *)data;
- unsigned long full_count = count, err;
- cpumask_t new_value;
-
- err = cpumask_parse_user(buffer, count, new_value);
- if (err)
- return err;
-
- *mask = new_value;
- return full_count;
-}
-
-void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir)
-{
- struct proc_dir_entry *entry;
-
- /* create /proc/irq/prof_cpu_mask */
- if (!(entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir)))
- return;
- entry->data = (void *)&prof_cpu_mask;
- entry->read_proc = prof_cpu_mask_read_proc;
- entry->write_proc = prof_cpu_mask_write_proc;
-}
-
-/*
- * This function accesses profiling information. The returned data is
- * binary: the sampling step and the actual contents of the profile
- * buffer. Use of the program readprofile is recommended in order to
- * get meaningful info out of these data.
- */
-static ssize_t
-read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos)
-{
- unsigned long p = *ppos;
- ssize_t read;
- char * pnt;
- unsigned int sample_step = 1 << prof_shift;
-
- profile_flip_buffers();
- if (p >= (prof_len+1)*sizeof(unsigned int))
- return 0;
- if (count > (prof_len+1)*sizeof(unsigned int) - p)
- count = (prof_len+1)*sizeof(unsigned int) - p;
- read = 0;
-
- while (p < sizeof(unsigned int) && count > 0) {
- if (put_user(*((char *)(&sample_step)+p),buf))
- return -EFAULT;
- buf++; p++; count--; read++;
- }
- pnt = (char *)prof_buffer + p - sizeof(atomic_t);
- if (copy_to_user(buf,(void *)pnt,count))
- return -EFAULT;
- read += count;
- *ppos += read;
- return read;
-}
-
-/*
- * Writing to /proc/profile resets the counters
- *
- * Writing a 'profiling multiplier' value into it also re-sets the profiling
- * interrupt frequency, on architectures that support this.
- */
-static ssize_t write_profile(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
-{
-#ifdef CONFIG_SMP
- extern int setup_profiling_timer (unsigned int multiplier);
-
- if (count == sizeof(int)) {
- unsigned int multiplier;
-
- if (copy_from_user(&multiplier, buf, sizeof(int)))
- return -EFAULT;
-
- if (setup_profiling_timer(multiplier))
- return -EINVAL;
- }
-#endif
- profile_discard_flip_buffers();
- memset(prof_buffer, 0, prof_len * sizeof(atomic_t));
- return count;
-}
-
-static const struct file_operations proc_profile_operations = {
- .read = read_profile,
- .write = write_profile,
-};
-
-#ifdef CONFIG_SMP
-static void __init profile_nop(void *unused)
-{
-}
-
-static int __init create_hash_tables(void)
-{
- int cpu;
-
- for_each_online_cpu(cpu) {
- int node = cpu_to_node(cpu);
- struct page *page;
-
- page = alloc_pages_node(node,
- GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
- 0);
- if (!page)
- goto out_cleanup;
- per_cpu(cpu_profile_hits, cpu)[1]
- = (struct profile_hit *)page_address(page);
- page = alloc_pages_node(node,
- GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
- 0);
- if (!page)
- goto out_cleanup;
- per_cpu(cpu_profile_hits, cpu)[0]
- = (struct profile_hit *)page_address(page);
- }
- return 0;
-out_cleanup:
- prof_on = 0;
- smp_mb();
- on_each_cpu(profile_nop, NULL, 0, 1);
- for_each_online_cpu(cpu) {
- struct page *page;
-
- if (per_cpu(cpu_profile_hits, cpu)[0]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
- per_cpu(cpu_profile_hits, cpu)[0] = NULL;
- __free_page(page);
- }
- if (per_cpu(cpu_profile_hits, cpu)[1]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[1]);
- per_cpu(cpu_profile_hits, cpu)[1] = NULL;
- __free_page(page);
- }
- }
- return -1;
-}
-#else
-#define create_hash_tables() ({ 0; })
-#endif
-
-static int __init create_proc_profile(void)
-{
- struct proc_dir_entry *entry;
-
- if (!prof_on)
- return 0;
- if (create_hash_tables())
- return -1;
- if (!(entry = create_proc_entry("profile", S_IWUSR | S_IRUGO, NULL)))
- return 0;
- entry->proc_fops = &proc_profile_operations;
- entry->size = (1+prof_len) * sizeof(atomic_t);
- hotcpu_notifier(profile_cpu_callback, 0);
- return 0;
-}
-module_init(create_proc_profile);
-#endif /* CONFIG_PROC_FS */
--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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