From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Wed, 15 Aug 2018 10:39:13 +0100 Subject: [PATCH v3 0/7] perf: Add ioctl for PMU driver configuration In-Reply-To: References: <1531950487-24554-1-git-send-email-mathieu.poirier@linaro.org> <20180813124642.3d49c082a95fc294d926016e@arm.com> <20180814120910.ed225bbc462c58b09e5d68de@arm.com> Message-ID: <20180815093912.GE2427@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Aug 14, 2018 at 01:42:27PM -0600, Mathieu Poirier wrote: > On Tue, 14 Aug 2018 at 11:09, Kim Phillips wrote: > > The other thing that's going on here is that I'm becoming numb to the > > loathsome "failed to mmap with 12 (Cannot allocate memory)" being > > returned no matter what the error is/was. E.g., an error that would > > indicate a sense of non-implementation would be much better > > appreciated than presumably what the above is doing, i.e., returning > > -ENOMEM. That, backed up with specific details in the form of human > > readable text in dmesg would be *most* welcome. > > As part of the refactoring of the code to support CPU-wide scenarios I > intend to emit better diagnostic messages from the driver. Modifying > rb_alloc_aux() to propagate the error message generated by the > architecture specific PMUs doesn't look hard either and I _may_ get to > it as part of this work. For the record, I will continue to oppose PMU drivers that dump diagnostics about user-controlled input into dmesg, but the coresight drivers are yours so it's up to you and I won't get in the way! Will