From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Thu, 27 Oct 2016 17:32:52 +0100 Subject: [PATCH v3] drivers: psci: PSCI checker module In-Reply-To: <9cf15020-5116-5082-d3d3-fba80fe2de70@arm.com> References: <20161026131752.GA15478@red-moon> <20161026151858.GQ3716@linux.vnet.ibm.com> <20161026171006.GA16248@red-moon> <20161026172252.GV3716@linux.vnet.ibm.com> <20161026173534.GC16248@red-moon> <20161026181148.GW3716@linux.vnet.ibm.com> <20161027091306.GA16603@red-moon> <20161027145446.GJ3716@linux.vnet.ibm.com> <9cf15020-5116-5082-d3d3-fba80fe2de70@arm.com> Message-ID: <20161027163252.GA18653@red-moon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Oct 27, 2016 at 05:06:00PM +0100, Kevin Brodsky wrote: > On 27/10/16 15:54, Paul E. McKenney wrote: > >On Thu, Oct 27, 2016 at 01:51:57PM +0100, Kevin Brodsky wrote: > >> On 27/10/16 10:13, Lorenzo Pieralisi wrote: > >>> On Wed, Oct 26, 2016 at 11:11:48AM -0700, Paul E. McKenney wrote: > >>>> On Wed, Oct 26, 2016 at 06:35:34PM +0100, Lorenzo Pieralisi wrote: > >>>>> On Wed, Oct 26, 2016 at 10:22:52AM -0700, Paul E. McKenney wrote: > >>>>>> On Wed, Oct 26, 2016 at 06:10:06PM +0100, Lorenzo Pieralisi wrote: > >>>> [ . . . ] > >>>> > >>>>>>> Thanks a lot for your feedback, thoughts appreciated. > >>>>>> Let me ask the question more directly. > >>>>>> > >>>>>> Why on earth are we trying to run these tests concurrently? > >>>>> We must prevent that, no question about that, that's why I started > >>>>> this discussion. It is not fine to enable this checker and the > >>>>> RCU/LOCK torture hotplug tests at the same time. > >>>>> > >>>>>> After all, if we just run one at a time in isolation, there is no > >>>>>> problem. > >>>>> Fine by me, it was to understand if the current assumptions we made > >>>>> are correct and they are definitely not. If we enable the PSCI checker > >>>>> we must disable the torture rcu/lock hotplug tests either statically or > >>>>> dynamically. > >>>> What rcutorture, locktorture, and rcuperf do is to invoke > >>>> torture_init_begin(), which returns false if one of these tests > >>>> is already running. > >>>> > >>>> Perhaps we should extract this torture-test-exclusion and require > >>>> than conflicting torture tests invoke it? > >>> Yes if it can be extracted as a check (but it should also prevent the > >>> torture tests from running and vice versa), either that or Kconfig > >>> dependency (which we could do as a first step, waiting to add the > >>> required interface to the torture test code ?). > >>> > >>> Thanks ! > >>> Lorenzo > >> > >> That sounds like a reasonable idea, but then that would mean that the PSCI checker > >> would have to wait until the torture test is finished if it is already running (and > >> the other way around). > >> > >> I wasn't aware that torture tests were hotplugging CPUs. I think that the most > >> sensible thing to do right now is to make CONFIG_PSCI_CHECKER depend on > >> !CONFIG_TORTURE_TEST (or maybe specifically !CONFIG_RCU_TORTURE_TEST && > >> !CONFIG_LOCK_TORTURE_TEST). We can try to make them work together afterwards, but for > >> the sake of getting this patch merged in a reasonable amount of time, I think we > >> should just exclude the conflicting tests at the build level in this patch. I'll also > >> update the comment accordingly. > > > >I suggest !CONFIG_TORTURE_TEST, given that there are a couple of other > >tests in the offing. > > > > Thanx, Paul > > Fair enough. If that's fine with Lorenzo, I'll add the dependency and post v4. Yes, that's fine by me, thanks a lot ! Lorenzo