On Tue, Oct 24, 2017 at 07:54:40PM +0000, Marciniszyn, Mike wrote: > > Subject: Re: [PATCH] IB/hfi1: Fix a wrapping test (make it less strict) > > > > On Mon, Oct 23, 2017 at 02:33:46PM -0400, Doug Ledford wrote: > > > > > > @@ -3781,7 +3781,7 @@ static int > > > > > > __subn_get_opa_hfi1_cong_log(struct > > > > > > opa_smp *smp, u32 am, > > > > > > * required to wrap the counter are supposed to > > > > > > * be zeroed (CA10-49 IBTA, release 1.2.1, V1). > > > > > > */ > > > > > > - if ((u64)(ts - cce->timestamp) > (2 * UINT_MAX)) > > > > > > + if ((u64)(ts - cce->timestamp) > (2ULL * > > > > > > UINT_MAX)) > > > > This is really weird looking. Both ts and cce->timestamp are s64, why > > do the convoluted conversion to unsigned? And surely UINT_MAX is not > > the right thing.. > > > > if ((ts - cce->timestamp)/2 > 0xFFFFFFFF) > > > > ? > > > > ktime_get is defined to be monotonic, so ts - cce->timestamp should > > never go negative. > > > > I agree that this is an issue. > > My proposal: > - Change s64 to u64 for ts and in timestamp in opa_hfi1_cong_log_event_internal > - Change the calls: > ktime_to_ns(ktime_get()) / 1024 > -- to -- > ktime_get_ns() / 1024 > - Change to use Jason's test from above with UINT_MAX > > Dan, we can do the patch or you can send a v2? > Can you do the patch and give me a Reported-by tag? regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
