2014-10-02 07:37, Neil Horman: > On Thu, Oct 02, 2014 at 09:47:19AM +0200, Thomas Monjalon wrote: > > 2014-10-01 17:05, Bruce Richardson: > > > On Wed, Oct 01, 2014 at 12:01:10PM -0400, Neil Horman wrote: > > > > On Wed, Oct 01, 2014 at 04:43:10PM +0100, Bruce Richardson wrote: > > > > > On Wed, Oct 01, 2014 at 11:02:27AM -0400, Neil Horman wrote: > > > > > > On Wed, Oct 01, 2014 at 03:36:45PM +0200, Thomas Monjalon wrote: > > > > > > > 2014-09-28 08:27, Neil Horman: > > > > > > > > On Sun, Sep 28, 2014 at 05:28:44AM +0000, Wiles, Roger Keith > > > > > > > > wrote: > > > > > > > > > Check the FILE *f and rte_mempool *mp pointers for NULL and > > > > > > > > > return plus print out a message if RTE_LIBRTE_MEMPOOL_DEBUG > > > > > > > > > is enabled. > > > > > > > > > > > > > > > > > > Signed-off-by: Keith Wiles <keith.wiles at windriver.com> > > > > > > > > > > > > > > > > I'm fine with this, as I think passing in a NULL mempool is > > > > > > > > clearly a bug here, > > > > > > > > thats worth panicing over, though I wouldnt mind if we did a > > > > > > > > RTE_VERIFY_WARN > > > > > > > > macro here instead using what I suggested in my other note > > > > > > > > > > > > > > Passing a NULL mempool to rte_mempool_dump() is a bug in the > > > > > > > application. > > > > > > > If you look elsewhere in the DPDK code, you'll see that it's not > > > > > > > common to do > > > > > > > such check on input parameters. > > > > > > > A similar discussion already happened few months ago: > > > > > > > http://dpdk.org/ml/archives/dev/2014-June/003900.html > > > > > > > > > > > > > Not sure what your point is here Thomas. I think we're all in > > > > > > agreement that > > > > > > NULL is a bad value to pass in here. Are you asserting that we > > > > > > shouldn't bother > > > > > > with a NULL check at all and just accept the crash as it is? > > > > > > > > > > > > > > > > In the general case: > > > > > * Code in the datapath should not have things like NULL checks > > > > > * However, datapath code should generally have a debug option which > > > > > turns > > > > > these checks on to help debugging if needed. > > > > > * Code not in the datapath probably should have these checks. > > > > > > > > > Ok, I can understand that, but I would hope that rte_mempool_dump isn't > > > > in the > > > > datapath, its rather by definition a debug function, isn't it? > > > > Neil > > > > > > Yes, agreed. [So it probably should have the NULL check]. > > > > I have many arguments to not do this check: > > 1) If it was a coding rule to do this kind of check, it should be done in > > almost every functions. > Only if NULL is an invalid value, and we spot check for NULL all the time (see > eal_parse_coremask as an example from a quick search). > > > 2) It's quite common to not do this check, e.g. what happen with > > memcpy(NULL,NULL)? > Its also quite common to do the check. I think this is more about if it makes > sense to do it here (i.e. is it a common error to pass a NULL pointer into > mempool_dump?). If so, an extra check with its own specific panic might be > nice. > > > 3) Why check only NULL value? 1 and 2 are also some invalid values... > > > Because NULL is the common case. > Neil
Argumentation accepted and patch applied. -- Thomas
