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authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-20 11:29:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-20 11:29:32 -0700
commit12e24f34cb0d55efd08c18b2112507d4bf498008 (patch)
tree83b07be17b8ef45f42360a3b9159b3aaae3fbad4 /kernel
parent1eb51c33b21ffa3fceb634d1d6bcd6488c79bc26 (diff)
parenteadc84cc01e04f9f74ec2de0c9355be035c7b396 (diff)
downloadlinux-2.6.34-ux500-12e24f34cb0d55efd08c18b2112507d4bf498008.tar.gz
Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits) perfcounter: Handle some IO return values perf_counter: Push perf_sample_data through the swcounter code perf_counter tools: Define and use our own u64, s64 etc. definitions perf_counter: Close race in perf_lock_task_context() perf_counter, x86: Improve interactions with fast-gup perf_counter: Simplify and fix task migration counting perf_counter tools: Add a data file header perf_counter: Update userspace callchain sampling uses perf_counter: Make callchain samples extensible perf report: Filter to parent set by default perf_counter tools: Handle lost events perf_counter: Add event overlow handling fs: Provide empty .set_page_dirty() aop for anon inodes perf_counter: tools: Makefile tweaks for 64-bit powerpc perf_counter: powerpc: Add processor back-end for MPC7450 family perf_counter: powerpc: Make powerpc perf_counter code safe for 32-bit kernels perf_counter: powerpc: Change how processor-specific back-ends get selected perf_counter: powerpc: Use unsigned long for register and constraint values perf_counter: powerpc: Enable use of software counters on 32-bit powerpc perf_counter tools: Add and use isprint() ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/perf_counter.c312
-rw-r--r--kernel/sched.c3
2 files changed, 180 insertions, 135 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 29b685f551a..1a933a221ea 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -124,7 +124,7 @@ void perf_enable(void)
static void get_ctx(struct perf_counter_context *ctx)
{
- atomic_inc(&ctx->refcount);
+ WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
}
static void free_ctx(struct rcu_head *head)
@@ -175,6 +175,11 @@ perf_lock_task_context(struct task_struct *task, unsigned long *flags)
spin_unlock_irqrestore(&ctx->lock, *flags);
goto retry;
}
+
+ if (!atomic_inc_not_zero(&ctx->refcount)) {
+ spin_unlock_irqrestore(&ctx->lock, *flags);
+ ctx = NULL;
+ }
}
rcu_read_unlock();
return ctx;
@@ -193,7 +198,6 @@ static struct perf_counter_context *perf_pin_task_context(struct task_struct *ta
ctx = perf_lock_task_context(task, &flags);
if (ctx) {
++ctx->pin_count;
- get_ctx(ctx);
spin_unlock_irqrestore(&ctx->lock, flags);
}
return ctx;
@@ -1283,7 +1287,7 @@ static void perf_ctx_adjust_freq(struct perf_counter_context *ctx)
if (!interrupts) {
perf_disable();
counter->pmu->disable(counter);
- atomic_set(&hwc->period_left, 0);
+ atomic64_set(&hwc->period_left, 0);
counter->pmu->enable(counter);
perf_enable();
}
@@ -1459,11 +1463,6 @@ static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
put_ctx(parent_ctx);
ctx->parent_ctx = NULL; /* no longer a clone */
}
- /*
- * Get an extra reference before dropping the lock so that
- * this context won't get freed if the task exits.
- */
- get_ctx(ctx);
spin_unlock_irqrestore(&ctx->lock, flags);
}
@@ -1553,7 +1552,7 @@ static int perf_release(struct inode *inode, struct file *file)
static ssize_t
perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
{
- u64 values[3];
+ u64 values[4];
int n;
/*
@@ -1620,22 +1619,6 @@ static void perf_counter_reset(struct perf_counter *counter)
perf_counter_update_userpage(counter);
}
-static void perf_counter_for_each_sibling(struct perf_counter *counter,
- void (*func)(struct perf_counter *))
-{
- struct perf_counter_context *ctx = counter->ctx;
- struct perf_counter *sibling;
-
- WARN_ON_ONCE(ctx->parent_ctx);
- mutex_lock(&ctx->mutex);
- counter = counter->group_leader;
-
- func(counter);
- list_for_each_entry(sibling, &counter->sibling_list, list_entry)
- func(sibling);
- mutex_unlock(&ctx->mutex);
-}
-
/*
* Holding the top-level counter's child_mutex means that any
* descendant process that has inherited this counter will block
@@ -1658,14 +1641,18 @@ static void perf_counter_for_each_child(struct perf_counter *counter,
static void perf_counter_for_each(struct perf_counter *counter,
void (*func)(struct perf_counter *))
{
- struct perf_counter *child;
+ struct perf_counter_context *ctx = counter->ctx;
+ struct perf_counter *sibling;
- WARN_ON_ONCE(counter->ctx->parent_ctx);
- mutex_lock(&counter->child_mutex);
- perf_counter_for_each_sibling(counter, func);
- list_for_each_entry(child, &counter->child_list, child_list)
- perf_counter_for_each_sibling(child, func);
- mutex_unlock(&counter->child_mutex);
+ WARN_ON_ONCE(ctx->parent_ctx);
+ mutex_lock(&ctx->mutex);
+ counter = counter->group_leader;
+
+ perf_counter_for_each_child(counter, func);
+ func(counter);
+ list_for_each_entry(sibling, &counter->sibling_list, list_entry)
+ perf_counter_for_each_child(counter, func);
+ mutex_unlock(&ctx->mutex);
}
static int perf_counter_period(struct perf_counter *counter, u64 __user *arg)
@@ -1806,6 +1793,12 @@ static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
struct perf_mmap_data *data;
int ret = VM_FAULT_SIGBUS;
+ if (vmf->flags & FAULT_FLAG_MKWRITE) {
+ if (vmf->pgoff == 0)
+ ret = 0;
+ return ret;
+ }
+
rcu_read_lock();
data = rcu_dereference(counter->data);
if (!data)
@@ -1819,9 +1812,16 @@ static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
if ((unsigned)nr > data->nr_pages)
goto unlock;
+ if (vmf->flags & FAULT_FLAG_WRITE)
+ goto unlock;
+
vmf->page = virt_to_page(data->data_pages[nr]);
}
+
get_page(vmf->page);
+ vmf->page->mapping = vma->vm_file->f_mapping;
+ vmf->page->index = vmf->pgoff;
+
ret = 0;
unlock:
rcu_read_unlock();
@@ -1874,6 +1874,14 @@ fail:
return -ENOMEM;
}
+static void perf_mmap_free_page(unsigned long addr)
+{
+ struct page *page = virt_to_page(addr);
+
+ page->mapping = NULL;
+ __free_page(page);
+}
+
static void __perf_mmap_data_free(struct rcu_head *rcu_head)
{
struct perf_mmap_data *data;
@@ -1881,9 +1889,10 @@ static void __perf_mmap_data_free(struct rcu_head *rcu_head)
data = container_of(rcu_head, struct perf_mmap_data, rcu_head);
- free_page((unsigned long)data->user_page);
+ perf_mmap_free_page((unsigned long)data->user_page);
for (i = 0; i < data->nr_pages; i++)
- free_page((unsigned long)data->data_pages[i]);
+ perf_mmap_free_page((unsigned long)data->data_pages[i]);
+
kfree(data);
}
@@ -1920,9 +1929,10 @@ static void perf_mmap_close(struct vm_area_struct *vma)
}
static struct vm_operations_struct perf_mmap_vmops = {
- .open = perf_mmap_open,
- .close = perf_mmap_close,
- .fault = perf_mmap_fault,
+ .open = perf_mmap_open,
+ .close = perf_mmap_close,
+ .fault = perf_mmap_fault,
+ .page_mkwrite = perf_mmap_fault,
};
static int perf_mmap(struct file *file, struct vm_area_struct *vma)
@@ -1936,7 +1946,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
long user_extra, extra;
int ret = 0;
- if (!(vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_WRITE))
+ if (!(vma->vm_flags & VM_SHARED))
return -EINVAL;
vma_size = vma->vm_end - vma->vm_start;
@@ -1995,10 +2005,12 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
atomic_long_add(user_extra, &user->locked_vm);
vma->vm_mm->locked_vm += extra;
counter->data->nr_locked = extra;
+ if (vma->vm_flags & VM_WRITE)
+ counter->data->writable = 1;
+
unlock:
mutex_unlock(&counter->mmap_mutex);
- vma->vm_flags &= ~VM_MAYWRITE;
vma->vm_flags |= VM_RESERVED;
vma->vm_ops = &perf_mmap_vmops;
@@ -2175,11 +2187,38 @@ struct perf_output_handle {
unsigned long head;
unsigned long offset;
int nmi;
- int overflow;
+ int sample;
int locked;
unsigned long flags;
};
+static bool perf_output_space(struct perf_mmap_data *data,
+ unsigned int offset, unsigned int head)
+{
+ unsigned long tail;
+ unsigned long mask;
+
+ if (!data->writable)
+ return true;
+
+ mask = (data->nr_pages << PAGE_SHIFT) - 1;
+ /*
+ * Userspace could choose to issue a mb() before updating the tail
+ * pointer. So that all reads will be completed before the write is
+ * issued.
+ */
+ tail = ACCESS_ONCE(data->user_page->data_tail);
+ smp_rmb();
+
+ offset = (offset - tail) & mask;
+ head = (head - tail) & mask;
+
+ if ((int)(head - offset) < 0)
+ return false;
+
+ return true;
+}
+
static void perf_output_wakeup(struct perf_output_handle *handle)
{
atomic_set(&handle->data->poll, POLL_IN);
@@ -2270,12 +2309,57 @@ out:
local_irq_restore(handle->flags);
}
+static void perf_output_copy(struct perf_output_handle *handle,
+ const void *buf, unsigned int len)
+{
+ unsigned int pages_mask;
+ unsigned int offset;
+ unsigned int size;
+ void **pages;
+
+ offset = handle->offset;
+ pages_mask = handle->data->nr_pages - 1;
+ pages = handle->data->data_pages;
+
+ do {
+ unsigned int page_offset;
+ int nr;
+
+ nr = (offset >> PAGE_SHIFT) & pages_mask;
+ page_offset = offset & (PAGE_SIZE - 1);
+ size = min_t(unsigned int, PAGE_SIZE - page_offset, len);
+
+ memcpy(pages[nr] + page_offset, buf, size);
+
+ len -= size;
+ buf += size;
+ offset += size;
+ } while (len);
+
+ handle->offset = offset;
+
+ /*
+ * Check we didn't copy past our reservation window, taking the
+ * possible unsigned int wrap into account.
+ */
+ WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0);
+}
+
+#define perf_output_put(handle, x) \
+ perf_output_copy((handle), &(x), sizeof(x))
+
static int perf_output_begin(struct perf_output_handle *handle,
struct perf_counter *counter, unsigned int size,
- int nmi, int overflow)
+ int nmi, int sample)
{
struct perf_mmap_data *data;
unsigned int offset, head;
+ int have_lost;
+ struct {
+ struct perf_event_header header;
+ u64 id;
+ u64 lost;
+ } lost_event;
/*
* For inherited counters we send all the output towards the parent.
@@ -2288,19 +2372,25 @@ static int perf_output_begin(struct perf_output_handle *handle,
if (!data)
goto out;
- handle->data = data;
- handle->counter = counter;
- handle->nmi = nmi;
- handle->overflow = overflow;
+ handle->data = data;
+ handle->counter = counter;
+ handle->nmi = nmi;
+ handle->sample = sample;
if (!data->nr_pages)
goto fail;
+ have_lost = atomic_read(&data->lost);
+ if (have_lost)
+ size += sizeof(lost_event);
+
perf_output_lock(handle);
do {
offset = head = atomic_long_read(&data->head);
head += size;
+ if (unlikely(!perf_output_space(data, offset, head)))
+ goto fail;
} while (atomic_long_cmpxchg(&data->head, offset, head) != offset);
handle->offset = offset;
@@ -2309,55 +2399,27 @@ static int perf_output_begin(struct perf_output_handle *handle,
if ((offset >> PAGE_SHIFT) != (head >> PAGE_SHIFT))
atomic_set(&data->wakeup, 1);
+ if (have_lost) {
+ lost_event.header.type = PERF_EVENT_LOST;
+ lost_event.header.misc = 0;
+ lost_event.header.size = sizeof(lost_event);
+ lost_event.id = counter->id;
+ lost_event.lost = atomic_xchg(&data->lost, 0);
+
+ perf_output_put(handle, lost_event);
+ }
+
return 0;
fail:
- perf_output_wakeup(handle);
+ atomic_inc(&data->lost);
+ perf_output_unlock(handle);
out:
rcu_read_unlock();
return -ENOSPC;
}
-static void perf_output_copy(struct perf_output_handle *handle,
- const void *buf, unsigned int len)
-{
- unsigned int pages_mask;
- unsigned int offset;
- unsigned int size;
- void **pages;
-
- offset = handle->offset;
- pages_mask = handle->data->nr_pages - 1;
- pages = handle->data->data_pages;
-
- do {
- unsigned int page_offset;
- int nr;
-
- nr = (offset >> PAGE_SHIFT) & pages_mask;
- page_offset = offset & (PAGE_SIZE - 1);
- size = min_t(unsigned int, PAGE_SIZE - page_offset, len);
-
- memcpy(pages[nr] + page_offset, buf, size);
-
- len -= size;
- buf += size;
- offset += size;
- } while (len);
-
- handle->offset = offset;
-
- /*
- * Check we didn't copy past our reservation window, taking the
- * possible unsigned int wrap into account.
- */
- WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0);
-}
-
-#define perf_output_put(handle, x) \
- perf_output_copy((handle), &(x), sizeof(x))
-
static void perf_output_end(struct perf_output_handle *handle)
{
struct perf_counter *counter = handle->counter;
@@ -2365,7 +2427,7 @@ static void perf_output_end(struct perf_output_handle *handle)
int wakeup_events = counter->attr.wakeup_events;
- if (handle->overflow && wakeup_events) {
+ if (handle->sample && wakeup_events) {
int events = atomic_inc_return(&data->events);
if (events >= wakeup_events) {
atomic_sub(wakeup_events, &data->events);
@@ -2970,7 +3032,7 @@ static void perf_log_throttle(struct perf_counter *counter, int enable)
}
/*
- * Generic counter overflow handling.
+ * Generic counter overflow handling, sampling.
*/
int perf_counter_overflow(struct perf_counter *counter, int nmi,
@@ -3109,20 +3171,15 @@ static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer)
}
static void perf_swcounter_overflow(struct perf_counter *counter,
- int nmi, struct pt_regs *regs, u64 addr)
+ int nmi, struct perf_sample_data *data)
{
- struct perf_sample_data data = {
- .regs = regs,
- .addr = addr,
- .period = counter->hw.last_period,
- };
+ data->period = counter->hw.last_period;
perf_swcounter_update(counter);
perf_swcounter_set_period(counter);
- if (perf_counter_overflow(counter, nmi, &data))
+ if (perf_counter_overflow(counter, nmi, data))
/* soft-disable the counter */
;
-
}
static int perf_swcounter_is_counting(struct perf_counter *counter)
@@ -3187,18 +3244,18 @@ static int perf_swcounter_match(struct perf_counter *counter,
}
static void perf_swcounter_add(struct perf_counter *counter, u64 nr,
- int nmi, struct pt_regs *regs, u64 addr)
+ int nmi, struct perf_sample_data *data)
{
int neg = atomic64_add_negative(nr, &counter->hw.count);
- if (counter->hw.sample_period && !neg && regs)
- perf_swcounter_overflow(counter, nmi, regs, addr);
+ if (counter->hw.sample_period && !neg && data->regs)
+ perf_swcounter_overflow(counter, nmi, data);
}
static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
- enum perf_type_id type, u32 event,
- u64 nr, int nmi, struct pt_regs *regs,
- u64 addr)
+ enum perf_type_id type,
+ u32 event, u64 nr, int nmi,
+ struct perf_sample_data *data)
{
struct perf_counter *counter;
@@ -3207,8 +3264,8 @@ static void perf_swcounter_ctx_event(struct perf_counter_context *ctx,
rcu_read_lock();
list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
- if (perf_swcounter_match(counter, type, event, regs))
- perf_swcounter_add(counter, nr, nmi, regs, addr);
+ if (perf_swcounter_match(counter, type, event, data->regs))
+ perf_swcounter_add(counter, nr, nmi, data);
}
rcu_read_unlock();
}
@@ -3227,9 +3284,9 @@ static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx)
return &cpuctx->recursion[0];
}
-static void __perf_swcounter_event(enum perf_type_id type, u32 event,
- u64 nr, int nmi, struct pt_regs *regs,
- u64 addr)
+static void do_perf_swcounter_event(enum perf_type_id type, u32 event,
+ u64 nr, int nmi,
+ struct perf_sample_data *data)
{
struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context);
int *recursion = perf_swcounter_recursion_context(cpuctx);
@@ -3242,7 +3299,7 @@ static void __perf_swcounter_event(enum perf_type_id type, u32 event,
barrier();
perf_swcounter_ctx_event(&cpuctx->ctx, type, event,
- nr, nmi, regs, addr);
+ nr, nmi, data);
rcu_read_lock();
/*
* doesn't really matter which of the child contexts the
@@ -3250,7 +3307,7 @@ static void __perf_swcounter_event(enum perf_type_id type, u32 event,
*/
ctx = rcu_dereference(current->perf_counter_ctxp);
if (ctx)
- perf_swcounter_ctx_event(ctx, type, event, nr, nmi, regs, addr);
+ perf_swcounter_ctx_event(ctx, type, event, nr, nmi, data);
rcu_read_unlock();
barrier();
@@ -3263,7 +3320,12 @@ out:
void
perf_swcounter_event(u32 event, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
{
- __perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, regs, addr);
+ struct perf_sample_data data = {
+ .regs = regs,
+ .addr = addr,
+ };
+
+ do_perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, &data);
}
static void perf_swcounter_read(struct perf_counter *counter)
@@ -3404,36 +3466,18 @@ static const struct pmu perf_ops_task_clock = {
.read = task_clock_perf_counter_read,
};
-/*
- * Software counter: cpu migrations
- */
-void perf_counter_task_migration(struct task_struct *task, int cpu)
-{
- struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
- struct perf_counter_context *ctx;
-
- perf_swcounter_ctx_event(&cpuctx->ctx, PERF_TYPE_SOFTWARE,
- PERF_COUNT_SW_CPU_MIGRATIONS,
- 1, 1, NULL, 0);
-
- ctx = perf_pin_task_context(task);
- if (ctx) {
- perf_swcounter_ctx_event(ctx, PERF_TYPE_SOFTWARE,
- PERF_COUNT_SW_CPU_MIGRATIONS,
- 1, 1, NULL, 0);
- perf_unpin_context(ctx);
- }
-}
-
#ifdef CONFIG_EVENT_PROFILE
void perf_tpcounter_event(int event_id)
{
- struct pt_regs *regs = get_irq_regs();
+ struct perf_sample_data data = {
+ .regs = get_irq_regs();
+ .addr = 0,
+ };
- if (!regs)
- regs = task_pt_regs(current);
+ if (!data.regs)
+ data.regs = task_pt_regs(current);
- __perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, 1, 1, regs, 0);
+ do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, 1, 1, &data);
}
EXPORT_SYMBOL_GPL(perf_tpcounter_event);
diff --git a/kernel/sched.c b/kernel/sched.c
index 92e51287b98..7c9098d186e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1978,7 +1978,8 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
if (task_hot(p, old_rq->clock, NULL))
schedstat_inc(p, se.nr_forced2_migrations);
#endif
- perf_counter_task_migration(p, new_cpu);
+ perf_swcounter_event(PERF_COUNT_SW_CPU_MIGRATIONS,
+ 1, 1, NULL, 0);
}
p->se.vruntime -= old_cfsrq->min_vruntime -
new_cfsrq->min_vruntime;