Hi, On 08/11/2014 09:08 PM, Guenter Roeck wrote: > On Mon, Aug 11, 2014 at 08:55:07PM +0200, Hans de Goede wrote: >> Hi, >> >> On 08/11/2014 08:19 PM, Guenter Roeck wrote: >>> On Mon, Aug 11, 2014 at 01:29:26PM +0530, Sanjeev Sharma wrote: >>>> spin_is_locked() always return false in uniprocessor configuration and >>>> therefore it >>>> would be advise to repalce with assert_spin_locked(). >>>> >>>> Signed-off-by: Sanjeev Sharma <sanjeev_sha...@mentor.com> >>>> --- >>>> drivers/usb/storage/uas.c | 8 ++++---- >>>> 1 file changed, 4 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c >>>> index 3f42785..8e5877d 100644 >>>> --- a/drivers/usb/storage/uas.c >>>> +++ b/drivers/usb/storage/uas.c >>>> @@ -154,7 +154,7 @@ static void uas_mark_cmd_dead(struct uas_dev_info >>>> *devinfo, >>>> struct scsi_cmnd *cmnd = container_of(scp, struct scsi_cmnd, SCp); >>>> >>>> uas_log_cmd_state(cmnd, caller); >>>> - WARN_ON_ONCE(!spin_is_locked(&devinfo->lock)); >>>> + assert_spin_locked(&devinfo->lock); >>> >>> Seems to me that replacing WARN_ON_ONCE (which may be annoying but only >>> creates a traceback, and only once) with assert_spin_locked (which >>> crashes the kernel) is a bit drastic. >> >> I can see your point, but so far these paranoia checks have never triggered, >> and having them trigger _always_ one some uni-processor (which is the reason >> for this patch) to me seems the worse problem of the 2. >> > If those are just paranoia checks, it might make sense to use > lockdep_assert_held() to reduce runtime overhead if lockdep > debugging is disabled.
Ah yes, that is a good idea. Sanjeev, can you please send a v2 using lockdep_assert_held() ? Thanks & Regards, Hans (the uas driver maintainer) -- 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/
