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authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-15 21:31:30 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-15 21:31:30 -0400
commita926021cb1f8a99a275eaf6eb546102e9469dc59 (patch)
treec6d0300cd4b1a1fd658708476db4577b68b4de31 /kernel/trace/ring_buffer.c
parent0586bed3e8563c2eb89bc7256e30ce633ae06cfb (diff)
parent5e814dd597c42daeb8d2a276e64a6ec986ad0e2a (diff)
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (184 commits) perf probe: Clean up probe_point_lazy_walker() return value tracing: Fix irqoff selftest expanding max buffer tracing: Align 4 byte ints together in struct tracer tracing: Export trace_set_clr_event() tracing: Explain about unstable clock on resume with ring buffer warning ftrace/graph: Trace function entry before updating index ftrace: Add .ref.text as one of the safe areas to trace tracing: Adjust conditional expression latency formatting. tracing: Fix event alignment: skb:kfree_skb tracing: Fix event alignment: mce:mce_record tracing: Fix event alignment: kvm:kvm_hv_hypercall tracing: Fix event alignment: module:module_request tracing: Fix event alignment: ftrace:context_switch and ftrace:wakeup tracing: Remove lock_depth from event entry perf header: Stop using 'self' perf session: Use evlist/evsel for managing perf.data attributes perf top: Don't let events to eat up whole header line perf top: Fix events overflow in top command ring-buffer: Remove unused #include <linux/trace_irq.h> tracing: Add an 'overwrite' trace_option. ...
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c24
1 files changed, 21 insertions, 3 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index bd1c35a4fbcc..db7b439d23ee 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5,7 +5,6 @@
5 */ 5 */
6#include <linux/ring_buffer.h> 6#include <linux/ring_buffer.h>
7#include <linux/trace_clock.h> 7#include <linux/trace_clock.h>
8#include <linux/ftrace_irq.h>
9#include <linux/spinlock.h> 8#include <linux/spinlock.h>
10#include <linux/debugfs.h> 9#include <linux/debugfs.h>
11#include <linux/uaccess.h> 10#include <linux/uaccess.h>
@@ -1429,6 +1428,17 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
1429} 1428}
1430EXPORT_SYMBOL_GPL(ring_buffer_resize); 1429EXPORT_SYMBOL_GPL(ring_buffer_resize);
1431 1430
1431void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
1432{
1433 mutex_lock(&buffer->mutex);
1434 if (val)
1435 buffer->flags |= RB_FL_OVERWRITE;
1436 else
1437 buffer->flags &= ~RB_FL_OVERWRITE;
1438 mutex_unlock(&buffer->mutex);
1439}
1440EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite);
1441
1432static inline void * 1442static inline void *
1433__rb_data_page_index(struct buffer_data_page *bpage, unsigned index) 1443__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
1434{ 1444{
@@ -2162,11 +2172,19 @@ rb_reserve_next_event(struct ring_buffer *buffer,
2162 if (likely(ts >= cpu_buffer->write_stamp)) { 2172 if (likely(ts >= cpu_buffer->write_stamp)) {
2163 delta = diff; 2173 delta = diff;
2164 if (unlikely(test_time_stamp(delta))) { 2174 if (unlikely(test_time_stamp(delta))) {
2175 int local_clock_stable = 1;
2176#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2177 local_clock_stable = sched_clock_stable;
2178#endif
2165 WARN_ONCE(delta > (1ULL << 59), 2179 WARN_ONCE(delta > (1ULL << 59),
2166 KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n", 2180 KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n%s",
2167 (unsigned long long)delta, 2181 (unsigned long long)delta,
2168 (unsigned long long)ts, 2182 (unsigned long long)ts,
2169 (unsigned long long)cpu_buffer->write_stamp); 2183 (unsigned long long)cpu_buffer->write_stamp,
2184 local_clock_stable ? "" :
2185 "If you just came from a suspend/resume,\n"
2186 "please switch to the trace global clock:\n"
2187 " echo global > /sys/kernel/debug/tracing/trace_clock\n");
2170 add_timestamp = 1; 2188 add_timestamp = 1;
2171 } 2189 }
2172 } 2190 }