lkml.org 
[lkml]   [2009]   [Apr]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 03/15] perf_counter: SIGIO support
provide support for fcntl() I/O availability signals.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
include/linux/perf_counter.h | 2 ++
kernel/perf_counter.c | 20 +++++++++++++++++++-
2 files changed, 21 insertions(+), 1 deletion(-)
Index: linux-2.6/include/linux/perf_counter.h
===================================================================
--- linux-2.6.orig/include/linux/perf_counter.h
+++ linux-2.6/include/linux/perf_counter.h
@@ -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;
@@ -397,6 +398,7 @@ struct perf_counter {

/* poll related */
wait_queue_head_t waitq;
+ struct fasync_struct *fasync;
/* optional: for NMIs */
struct perf_wakeup_entry wakeup;

Index: linux-2.6/kernel/perf_counter.c
===================================================================
--- linux-2.6.orig/kernel/perf_counter.c
+++ linux-2.6/kernel/perf_counter.c
@@ -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
.unlocked_ioctl = perf_ioctl,
.compat_ioctl = perf_ioctl,
.mmap = perf_mmap,
+ .fasync = perf_fasync,
};

/*
@@ -1549,7 +1566,7 @@ void perf_counter_wakeup(struct perf_cou
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_cou
rcu_read_unlock();

wake_up_all(&counter->waitq);
+ kill_fasync(&counter->fasync, SIGIO, POLL_IN);
}

/*
--



\
 
 \ /
  Last update: 2009-04-06 11:49    [from the cache]
©2003-2011 Jasper Spaans