diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 51ba681b915a979e5475eecf3fc89c71623b3af6..affdd890899ecf17fcb32cac22bd5e76863d8d09 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -100,7 +100,6 @@ enum cpuhp_state {
CPUHP_WORKQUEUE_PREP,
CPUHP_POWER_NUMA_PREPARE,
CPUHP_HRTIMERS_PREPARE,
- CPUHP_PROFILE_PREPARE,
CPUHP_X2APIC_PREPARE,
CPUHP_SMPCFD_PREPARE,
CPUHP_RELAY_PREPARE,
diff --git a/kernel/profile.c b/kernel/profile.c
index 4654c6cd984e4cc761c467e5ee5df57a15d83ebc..2dfb0f4e755c5fbd51ad4985243d5badc548758d 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -129,180 +129,13 @@ int __ref profile_init(void)
return -ENOMEM;
}
-#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS)
-/*
- * 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.
- *
- * -- nyc
- */
-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, 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, 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);
-}
-
-static void do_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;
-
- 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 profile_dead_cpu(unsigned int cpu)
-{
- struct page *page;
- int i;
-
- for (i = 0; i < 2; i++) {
- if (per_cpu(cpu_profile_hits, cpu)[i]) {
- page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[i]);
- per_cpu(cpu_profile_hits, cpu)[i] = NULL;
- __free_page(page);
- }
- }
- return 0;
-}
-
-static int profile_prepare_cpu(unsigned int cpu)
-{
- int i, node = cpu_to_mem(cpu);
- struct page *page;
-
- per_cpu(cpu_profile_flip, cpu) = 0;
-
- for (i = 0; i < 2; i++) {
- if (per_cpu(cpu_profile_hits, cpu)[i])
- continue;
-
- page = __alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
- if (!page) {
- profile_dead_cpu(cpu);
- return -ENOMEM;
- }
- per_cpu(cpu_profile_hits, cpu)[i] = page_address(page);
-
- }
- return 0;
-}
-
-#else /* !CONFIG_SMP */
-#define profile_flip_buffers() do { } while (0)
-#define profile_discard_flip_buffers() do { } while (0)
-
static void do_profile_hits(int type, void *__pc, unsigned int nr_hits)
{
unsigned long pc;
pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift;
- atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]);
+ if (pc < prof_len)
+ atomic_add(nr_hits, &prof_buffer[pc]);
}
-#endif /* !CONFIG_SMP */
void profile_hits(int type, void *__pc, unsigned int nr_hits)
{
@@ -340,7 +173,6 @@ read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos)
char *pnt;
unsigned long sample_step = 1UL << prof_shift;
- profile_flip_buffers();
if (p >= (prof_len+1)*sizeof(unsigned int))
return 0;
if (count > (prof_len+1)*sizeof(unsigned int) - p)
@@ -386,7 +218,6 @@ static ssize_t write_profile(struct file *file, const char __user *buf,
return -EINVAL;
}
#endif
- profile_discard_flip_buffers();
memset(prof_buffer, 0, prof_len * sizeof(atomic_t));
return count;
}
@@ -404,20 +235,10 @@ int __ref create_proc_profile(void)
if (!prof_on)
return 0;
-#ifdef CONFIG_SMP
- err = cpuhp_setup_state(CPUHP_PROFILE_PREPARE, "PROFILE_PREPARE",
- profile_prepare_cpu, profile_dead_cpu);
- if (err)
- return err;
-#endif
entry = proc_create("profile", S_IWUSR | S_IRUGO,
NULL, &profile_proc_ops);
if (entry)
proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t));
-#ifdef CONFIG_SMP
- else
- cpuhp_remove_state(CPUHP_PROFILE_PREPARE);
-#endif
return err;
}
subsys_initcall(create_proc_profile);