On Tue, Mar 13, 2012 at 09:41:35AM -0700, Dan Magenheimer wrote: > > From: Jörg Sommer [mailto:joerg@xxxxxxxxxxxx] > > Sent: Monday, March 12, 2012 2:01 PM > > To: Greg Kroah-Hartman > > Cc: Dan Magenheimer; Seth Jennings; devel@xxxxxxxxxxxxxxxxxxxx > > Subject: Re: [PATCH] zcache: Use WARN_ON_SMP in ASSERT_SPINLOCK > > > > Greg Kroah-Hartman hat am Sun 11. Mar, 19:50 (-0700) geschrieben: > > > On Sun, Mar 11, 2012 at 10:00:54PM +0100, Jörg Sommer wrote: > > > > As the description of WARN_ON_SMP in bug.h says, one can not use > > > > spin_is_locked() in assertions for non‐SMP configurations, because it > > > > always returns the lock is not held. Otherwise a warning is thrown > > > > everytime on a uniprocessor system. > > > > --- > > > > drivers/staging/zcache/tmem.h | 2 +- > > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > > > diff --git a/drivers/staging/zcache/tmem.h b/drivers/staging/zcache/tmem.h > > > > index ed147c4..b543694 100644 > > > > --- a/drivers/staging/zcache/tmem.h > > > > +++ b/drivers/staging/zcache/tmem.h > > > > @@ -47,7 +47,7 @@ > > > > #define ASSERT_INVERTED_SENTINEL(_x, _y) do { } while (0) > > > > #endif > > > > > > > > -#define ASSERT_SPINLOCK(_l) WARN_ON(!spin_is_locked(_l)) > > > > +#define ASSERT_SPINLOCK(_l) WARN_ON_SMP(!spin_is_locked(_l)) > > > > > > Why do we even have asserts in this code in the first place? Shouldn't > > > they all be removed by now? > > > > I don't know, why the asserts are there. But if the asserts get removed, > > the sentinel zones can be removed, too, because noone checks them. This > > would be a big interference. If the code is stable enough, it can be > > cleaned up. But I can't say anything about it. I couldn't use zcache > > until now, because the kernel flooded the log with warnings. > > > > Regards, Jörg. > > -- > > Der Klügere gibt so lange nach bis er der Dumme ist. > > Hi Jorg and Greg -- > > Jorg, thanks for fixing that! I admit I never run with SMP > disabled anymore so I'm sorry it interfered with your use. Can I get your ack for this? > Greg, I think while zcache is continuing rapid development > (e.g Seth and Nitin's new allocator, my RAMster layer built > on top of zcache, etc.) and being used by new architectures > (PowerPC and ARM), it makes sense to retain the assertions. > Most or all should be removed before promotion out of staging. > If you disagree, please let us know! Ok, they are fine for now, but they need to be removed to get the code out of staging. thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
