ftrace: allow the event pipe to be polled (2a2cc8f7) · Commits · e / devices / android_kernel_teracube_2e

kernel/trace/trace.c

+38 −1

Original line number	Original line	Diff line number	Diff line
	@@ -24,6 +24,7 @@
	#include <linux/percpu.h>		#include <linux/percpu.h>
	#include <linux/ctype.h>		#include <linux/ctype.h>
	#include <linux/init.h>		#include <linux/init.h>
			#include <linux/poll.h>
	#include <linux/gfp.h>		#include <linux/gfp.h>
	#include <linux/fs.h>		#include <linux/fs.h>

	@@ -63,6 +64,7 @@ static struct tracer *current_trace __read_mostly;
	static int max_tracer_type_len;		static int max_tracer_type_len;

	static DEFINE_MUTEX(trace_types_lock);		static DEFINE_MUTEX(trace_types_lock);
			static DECLARE_WAIT_QUEUE_HEAD (trace_wait);

	#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))		#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))

	@@ -105,6 +107,7 @@ enum trace_iterator_flags {
	TRACE_ITER_RAW = 0x10,		TRACE_ITER_RAW = 0x10,
	TRACE_ITER_HEX = 0x20,		TRACE_ITER_HEX = 0x20,
	TRACE_ITER_BIN = 0x40,		TRACE_ITER_BIN = 0x40,
			TRACE_ITER_BLOCK = 0x80,
	};		};

	#define TRACE_ITER_SYM_MASK \		#define TRACE_ITER_SYM_MASK \
	@@ -119,6 +122,7 @@ static const char *trace_options[] = {
	"raw",		"raw",
	"hex",		"hex",
	"bin",		"bin",
			"block",
	NULL		NULL
	};		};

	@@ -650,6 +654,9 @@ __ftrace(struct trace_array tr, struct trace_array_cpu data,
	entry->fn.ip = ip;		entry->fn.ip = ip;
	entry->fn.parent_ip = parent_ip;		entry->fn.parent_ip = parent_ip;
	spin_unlock_irqrestore(&data->lock, irq_flags);		spin_unlock_irqrestore(&data->lock, irq_flags);

			if (!(trace_flags & TRACE_ITER_BLOCK))
			wake_up (&trace_wait);
	}		}

	notrace void		notrace void
	@@ -675,6 +682,9 @@ trace_special(struct trace_array tr, struct trace_array_cpu data,
	entry->special.arg2 = arg2;		entry->special.arg2 = arg2;
	entry->special.arg3 = arg3;		entry->special.arg3 = arg3;
	spin_unlock_irqrestore(&data->lock, irq_flags);		spin_unlock_irqrestore(&data->lock, irq_flags);

			if (!(trace_flags & TRACE_ITER_BLOCK))
			wake_up (&trace_wait);
	}		}

	notrace void		notrace void
	@@ -696,6 +706,9 @@ tracing_sched_switch_trace(struct trace_array *tr,
	entry->ctx.next_pid = next->pid;		entry->ctx.next_pid = next->pid;
	entry->ctx.next_prio = next->prio;		entry->ctx.next_prio = next->prio;
	spin_unlock_irqrestore(&data->lock, irq_flags);		spin_unlock_irqrestore(&data->lock, irq_flags);

			if (!(trace_flags & TRACE_ITER_BLOCK))
			wake_up (&trace_wait);
	}		}

	#ifdef CONFIG_FTRACE		#ifdef CONFIG_FTRACE
	@@ -1765,7 +1778,6 @@ static struct file_operations tracing_readme_fops = {
	.read = tracing_readme_read,		.read = tracing_readme_read,
	};		};


	static ssize_t		static ssize_t
	tracing_ctrl_read(struct file filp, char __user ubuf,		tracing_ctrl_read(struct file filp, char __user ubuf,
	size_t cnt, loff_t *ppos)		size_t cnt, loff_t *ppos)
	@@ -1953,6 +1965,28 @@ static int tracing_release_pipe(struct inode inode, struct file file)
	return 0;		return 0;
	}		}

			static unsigned int
			tracing_poll_pipe(struct file filp, poll_table poll_table)
			{
			struct trace_iterator *iter = filp->private_data;

			if (trace_flags & TRACE_ITER_BLOCK) {
			/*
			* Always select as readable when in blocking mode
			*/
			return POLLIN \| POLLRDNORM;
			}
			else {
			if (!trace_empty(iter))
			return POLLIN \| POLLRDNORM;
			poll_wait(filp, &trace_wait, poll_table);
			if (!trace_empty(iter))
			return POLLIN \| POLLRDNORM;

			return 0;
			}
			}

	/*		/*
	* Consumer reader.		* Consumer reader.
	*/		*/
	@@ -1991,6 +2025,8 @@ tracing_read_pipe(struct file filp, char __user ubuf,
	start = 0;		start = 0;

	while (trace_empty(iter)) {		while (trace_empty(iter)) {
			if (!(trace_flags & TRACE_ITER_BLOCK))
			return -EWOULDBLOCK;
	/*		/*
	* This is a make-shift waitqueue. The reason we don't use		* This is a make-shift waitqueue. The reason we don't use
	* an actual wait queue is because:		* an actual wait queue is because:
	@@ -2134,6 +2170,7 @@ static struct file_operations set_tracer_fops = {

	static struct file_operations tracing_pipe_fops = {		static struct file_operations tracing_pipe_fops = {
	.open = tracing_open_pipe,		.open = tracing_open_pipe,
			.poll = tracing_poll_pipe,
	.read = tracing_read_pipe,		.read = tracing_read_pipe,
	.release = tracing_release_pipe,		.release = tracing_release_pipe,
	};		};