perf_counter: SIGIO support

Provide support for fcntl() I/O availability signals.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.579788800@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-04-06 11:45:01 +02:00 committed by Ingo Molnar
parent 9c03d88e32
commit 3c446b3d3b
2 changed files with 21 additions and 1 deletions

View file

@ -238,6 +238,7 @@ enum perf_event_type {
#include <linux/rcupdate.h>
#include <linux/spinlock.h>
#include <linux/hrtimer.h>
#include <linux/fs.h>
#include <asm/atomic.h>
struct task_struct;
@ -398,6 +399,7 @@ struct perf_counter {
/* poll related */
wait_queue_head_t waitq;
struct fasync_struct *fasync;
/* optional: for NMIs */
struct perf_wakeup_entry wakeup;

View file

@ -1526,6 +1526,22 @@ out:
return ret;
}
static int perf_fasync(int fd, struct file *filp, int on)
{
struct perf_counter *counter = filp->private_data;
struct inode *inode = filp->f_path.dentry->d_inode;
int retval;
mutex_lock(&inode->i_mutex);
retval = fasync_helper(fd, filp, on, &counter->fasync);
mutex_unlock(&inode->i_mutex);
if (retval < 0)
return retval;
return 0;
}
static const struct file_operations perf_fops = {
.release = perf_release,
.read = perf_read,
@ -1533,6 +1549,7 @@ static const struct file_operations perf_fops = {
.unlocked_ioctl = perf_ioctl,
.compat_ioctl = perf_ioctl,
.mmap = perf_mmap,
.fasync = perf_fasync,
};
/*
@ -1549,7 +1566,7 @@ void perf_counter_wakeup(struct perf_counter *counter)
rcu_read_lock();
data = rcu_dereference(counter->data);
if (data) {
(void)atomic_xchg(&data->wakeup, POLL_IN);
atomic_set(&data->wakeup, POLL_IN);
/*
* Ensure all data writes are issued before updating the
* user-space data head information. The matching rmb()
@ -1561,6 +1578,7 @@ void perf_counter_wakeup(struct perf_counter *counter)
rcu_read_unlock();
wake_up_all(&counter->waitq);
kill_fasync(&counter->fasync, SIGIO, POLL_IN);
}
/*