From: Jeremy Kerr Date: Wed, 15 Oct 2008 02:16:18 +0000 (+1100) Subject: powerpc/spufs: sputrace: Only enable logging on open(), prevent multiple openers X-Git-Tag: v2.6.28-rc1~58^2~37 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=baf399273f2ea38e2fcbd4d0b6cc7ba7f7db43eb;p=linux-2.6-omap-h63xx.git powerpc/spufs: sputrace: Only enable logging on open(), prevent multiple openers Currently, sputrace will start logging to the event buffer before the log buffer has been open()ed. This results in a heap of "lost samples" warnings if the sputrace file hasn't yet been opened. Since the buffer is reset on open() anyway, there's no need to enable logging when no-one has opened the log. Because open clears the log, make it return EBUSY for mutliple open calls. Signed-off-by: Jeremy Kerr --- diff --git a/arch/powerpc/platforms/cell/spufs/sputrace.c b/arch/powerpc/platforms/cell/spufs/sputrace.c index 92d20e993ed..50cae0cf098 100644 --- a/arch/powerpc/platforms/cell/spufs/sputrace.c +++ b/arch/powerpc/platforms/cell/spufs/sputrace.c @@ -40,6 +40,7 @@ static DECLARE_WAIT_QUEUE_HEAD(sputrace_wait); static ktime_t sputrace_start; static unsigned long sputrace_head, sputrace_tail; static struct sputrace *sputrace_log; +static int sputrace_logging; static int sputrace_used(void) { @@ -109,24 +110,49 @@ static ssize_t sputrace_read(struct file *file, char __user *buf, static int sputrace_open(struct inode *inode, struct file *file) { + int rc; + spin_lock(&sputrace_lock); + if (sputrace_logging) { + rc = -EBUSY; + goto out; + } + + sputrace_logging = 1; sputrace_head = sputrace_tail = 0; sputrace_start = ktime_get(); + rc = 0; + +out: spin_unlock(&sputrace_lock); + return rc; +} +static int sputrace_release(struct inode *inode, struct file *file) +{ + spin_lock(&sputrace_lock); + sputrace_logging = 0; + spin_unlock(&sputrace_lock); return 0; } static const struct file_operations sputrace_fops = { - .owner = THIS_MODULE, - .open = sputrace_open, - .read = sputrace_read, + .owner = THIS_MODULE, + .open = sputrace_open, + .read = sputrace_read, + .release = sputrace_release, }; static void sputrace_log_item(const char *name, struct spu_context *ctx, struct spu *spu) { spin_lock(&sputrace_lock); + + if (!sputrace_logging) { + spin_unlock(&sputrace_lock); + return; + } + if (sputrace_avail() > 1) { struct sputrace *t = sputrace_log + sputrace_head;