Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4]

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> ok, next attempt. Please apply this patch and do the changeall-tree
> thing in the sound/ directory. This should in theory switch the ALSA
> ioctls (and only them) to a BKL-less variant.

ok, new version - the previous one was slighly racy. The one below works
better - it boots on my box and simple audio playback (xmms) works.

	Ingo

--- linux/sound/core/pcm_native.c.orig2	
+++ linux/sound/core/pcm_native.c	
@@ -3317,7 +3317,7 @@ static struct file_operations snd_pcm_f_
 	.open =		snd_pcm_open,
 	.release =	snd_pcm_release,
 	.poll =		snd_pcm_playback_poll,
-	.ioctl =	snd_pcm_playback_ioctl,
+	.ioctl2 =	snd_pcm_playback_ioctl,
 	.mmap =		snd_pcm_mmap,
 	.fasync =	snd_pcm_fasync,
 };
@@ -3329,7 +3329,7 @@ static struct file_operations snd_pcm_f_
 	.open =		snd_pcm_open,
 	.release =	snd_pcm_release,
 	.poll =		snd_pcm_capture_poll,
-	.ioctl =	snd_pcm_capture_ioctl,
+	.ioctl2 =	snd_pcm_capture_ioctl,
 	.mmap =		snd_pcm_mmap,
 	.fasync =	snd_pcm_fasync,
 };
--- linux/sound/pci/ali5451/ali5451.c.orig2	
+++ linux/sound/pci/ali5451/ali5451.c	
@@ -33,6 +33,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/moduleparam.h>
+#include <linux/syscalls.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/info.h>
@@ -985,11 +986,11 @@ static void snd_ali_update_ptr(ali_t *co
 	pvoice = &codec->synth.voices[channel];
 	runtime = pvoice->substream->runtime;
 
-	udelay(100);
 	spin_lock(&codec->reg_lock);
 
 	if (pvoice->pcm && pvoice->substream) {
 		/* pcm interrupt */
+		sys_gettimeofday((void *)0, (void *)1); // start the tracer
 #ifdef ALI_DEBUG
 		outb((u8)(pvoice->number), ALI_REG(codec, ALI_GC_CIR));
 		temp = inw(ALI_REG(codec, ALI_CSO_ALPHA_FMS + 2));
--- linux/fs/ioctl.c.orig2	
+++ linux/fs/ioctl.c	
@@ -68,6 +68,13 @@ asmlinkage long sys_ioctl(unsigned int f
                 goto out;
         }
 
+	error = -ENOTTY;
+	if (filp->f_op && filp->f_op->ioctl2) {
+		error = filp->f_op->ioctl2(filp->f_dentry->d_inode, filp, cmd, arg);
+		fput(filp);
+		return error;
+	}
+
 	lock_kernel();
 	switch (cmd) {
 		case FIOCLEX:
@@ -132,7 +139,6 @@ asmlinkage long sys_ioctl(unsigned int f
 	}
 	unlock_kernel();
 	fput(filp);
-
 out:
 	return error;
 }
--- linux/include/linux/fs.h.orig2	
+++ linux/include/linux/fs.h	
@@ -993,6 +993,7 @@ struct file_operations {
 	int (*check_flags)(int);
 	int (*dir_notify)(struct file *filp, unsigned long arg);
 	int (*flock) (struct file *, int, struct file_lock *);
+	int (*ioctl2) (struct inode *, struct file *, unsigned int, unsigned long);
 };
 
 struct inode_operations {