Friday, May 2, 2014, 6:13:09 PM, you wrote: > At Fri, 2 May 2014 15:09:27 +0200, > Sander Eikelenboom wrote: >> >> This (widely used) construction: >> >> if(printk_ratelimit()) >> dev_dbg() >> >> Causes the ratelimiting to spam the kernel log with the "callbacks >> suppressed" >> message below, even while the dev_dbg it is supposed to rate limit wouldn't >> print anything because DEBUG is not defined for this device. >> >> [ 533.803964] retire_playback_urb: 852 callbacks suppressed >> [ 538.807930] retire_playback_urb: 852 callbacks suppressed >> [ 543.811897] retire_playback_urb: 852 callbacks suppressed >> [ 548.815745] retire_playback_urb: 852 callbacks suppressed >> [ 553.819826] retire_playback_urb: 852 callbacks suppressed >> >> So use dev_dbg_ratelimited() instead of this construction. >> >> Signed-off-by: Sander Eikelenboom <li...@eikelenboom.it>
> Thanks, applied. This is a result of the recent rewrite to dev_dbg() > from plain printk(), I suppose. Yes that patch (https://lkml.org/lkml/2014/4/9/457) prevented spamming the kernel log when debugging was enabled .. but now the rate limiting code starts spamming the kernel log instead :-) I must say i wasn't very aware of that effect either and also used this construction on debug patches. > Takashi >> --- >> sound/usb/pcm.c | 5 ++--- >> 1 file changed, 2 insertions(+), 3 deletions(-) >> >> diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c >> index 131336d..c62a165 100644 >> --- a/sound/usb/pcm.c >> +++ b/sound/usb/pcm.c >> @@ -1501,9 +1501,8 @@ static void retire_playback_urb(struct >> snd_usb_substream *subs, >> * The error should be lower than 2ms since the estimate relies >> * on two reads of a counter updated every ms. >> */ >> - if (printk_ratelimit() && >> - abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2) >> - dev_dbg(&subs->dev->dev, >> + if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2) >> + dev_dbg_ratelimited(&subs->dev->dev, >> "delay: estimated %d, actual %d\n", >> est_delay, subs->last_delay); >> >> -- >> 1.7.10.4 >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
