Merge branch 'tip/perf/core' of... (92af1abd) · Commits · e / devices / android_kernel_samsung_universal8890

kernel/trace/ring_buffer.c

+17 −2

Original line number	Diff line number	Diff line
		@@ -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);

+0 −6

Original line number	Diff line number	Diff line
		@@ -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)