> -----Original Message----- > From: linux-rdma-owner@xxxxxxxxxxxxxxx [mailto:linux-rdma- > owner@xxxxxxxxxxxxxxx] On Behalf Of Jason Gunthorpe > Sent: Tuesday, November 14, 2017 6:55 PM > To: Ruhl, Michael J <michael.j.ruhl@xxxxxxxxx> > Cc: linux-rdma@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v3 3/4] ibacm: Fix a retry loop calculation race condition > > On Tue, Nov 14, 2017 at 11:43:47AM -0500, Michael J. Ruhl wrote: > > > diff --git a/ibacm/prov/acmp/src/acmp.c b/ibacm/prov/acmp/src/acmp.c > > index d707b8e..884fc48 100644 > > +++ b/ibacm/prov/acmp/src/acmp.c > > @@ -1579,10 +1579,12 @@ static void *acmp_retry_handler(void *context) > > pthread_mutex_unlock(&acmp_dev_lock); > > > > acmp_process_timeouts(); > > - wait = (int) (next_expire - time_stamp_ms()); > > - if (wait > 0 && atomic_get(&wait_cnt)) { > > - pthread_testcancel(); > > - event_wait(&timeout_event, wait); > > + if (next_expire != -1) { > > + wait = (int) (next_expire - time_stamp_ms()); > > This (int) cast is also wrong.. > > If you want to do signed subtraction then you need to cast the > arguments to '-' not the result, and since time_stamp_ms() is u64, > casting it to int will truncate. > > wait needs to be int64_t, next_expire should be int64_t and then no > casts are needed. Hmm, I think that the truncate is what is happening when delay issue (caused by the race condition) occurs. I need to explore this some more, your suggested change my obviate the issue. > All of time_stamp_* should return int64_t > > And the #define time_stamp_* should not be macros, but inline > functions returning int64_t to make the return type guarenteed and > clear. > > This isn't really related to this series, but if you send a followup > patch it would be nice since it has been now been noticed :) I will do this in a follow on patch, but need more time to test so it will not be in this series. Thanks for the comments! Mike > Jason > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
