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Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent

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This commit is contained in:
Ingo Molnar 2010-05-28 10:24:03 +02:00
commit 92af1abde4
2 changed files with 17 additions and 8 deletions
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19
kernel/trace/ring_buffer.c
View File

@ -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);

6
kernel/trace/trace.c
View File

@ -3661,7 +3661,6 @@ 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;
@ -3688,11 +3687,6 @@ 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)