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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-04-06 11:45:01 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-07 10:48:55 +0200 |
| commit | 3c446b3d3b38f991f97e9d2df0ad26a60a94dcff (patch) | |
| tree | fc4a7bdf50f34eb1a7343afdcc980355ccce5e97 | |
| parent | 9c03d88e328d5f28f13191622c2ea1349c36b799 (diff) | |
| download | lwn-3c446b3d3b38f991f97e9d2df0ad26a60a94dcff.tar.gz lwn-3c446b3d3b38f991f97e9d2df0ad26a60a94dcff.zip | |
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>
| -rw-r--r-- | include/linux/perf_counter.h | 2 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 20 |
2 files changed, 21 insertions, 1 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index f9d5cf0bfbdd..8d5d11b8d011 100644 --- a/include/linux/perf_counter.h +++ b/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; @@ -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; diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 727624db5078..c58cc64319e1 100644 --- a/kernel/perf_counter.c +++ b/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_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); } /* |