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authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-30 12:35:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-30 12:35:01 -0700
commitbc7d352c5e76c74c628a39b99777a1bdddde5e81 (patch)
tree3cc0a80defb54d284e2a9a1e69b1224064921775 /kernel
parentb3f2f6cd1ff935ecac9a5346904b899d7af689fe (diff)
parent92af1abde4f2d74c9e5f7b670a1971779ed0b051 (diff)
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Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf tui: Fix last use_browser problem related to .perfconfig perf symbols: Add the build id cache to the vmlinux path perf tui: Reset use_browser if stdout is not a tty ring-buffer: Move zeroing out excess in page to ring buffer code ring-buffer: Reset "real_end" when page is filled
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/ring_buffer.c19
-rw-r--r--kernel/trace/trace.c6
2 files changed, 17 insertions, 8 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 7f6059c5aa9..1da7b6ea8b8 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1768,6 +1768,14 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer,
* must fill the old tail_page with padding.
*/
if (tail >= BUF_PAGE_SIZE) {
+ /*
+ * If the page was filled, then we still need
+ * to update the real_end. Reset it to zero
+ * and the reader will ignore it.
+ */
+ if (tail == BUF_PAGE_SIZE)
+ tail_page->real_end = 0;
+
local_sub(length, &tail_page->write);
return;
}
@@ -3894,12 +3902,12 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
ret = read;
cpu_buffer->lost_events = 0;
+
+ commit = local_read(&bpage->commit);
/*
* Set a flag in the commit field if we lost events
*/
if (missed_events) {
- commit = local_read(&bpage->commit);
-
/* If there is room at the end of the page to save the
* missed events, then record it there.
*/
@@ -3907,10 +3915,17 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
memcpy(&bpage->data[commit], &missed_events,
sizeof(missed_events));
local_add(RB_MISSED_STORED, &bpage->commit);
+ commit += sizeof(missed_events);
}
local_add(RB_MISSED_EVENTS, &bpage->commit);
}
+ /*
+ * This page may be off to user land. Zero it out here.
+ */
+ if (commit < BUF_PAGE_SIZE)
+ memset(&bpage->data[commit], 0, BUF_PAGE_SIZE - commit);
+
out_unlock:
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 55e48511d7c..086d3631680 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3666,7 +3666,6 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
size_t count, loff_t *ppos)
{
struct ftrace_buffer_info *info = filp->private_data;
- unsigned int pos;
ssize_t ret;
size_t size;
@@ -3693,11 +3692,6 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
if (ret < 0)
return 0;
- pos = ring_buffer_page_len(info->spare);
-
- if (pos < PAGE_SIZE)
- memset(info->spare + pos, 0, PAGE_SIZE - pos);
-
read:
size = PAGE_SIZE - info->read;
if (size > count)