From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0BC5E6E563 for ; Tue, 31 Mar 2020 07:36:57 +0000 (UTC) References: <20200327044250.64274-1-ashutosh.dixit@intel.com> <87wo76s8or.wl-ashutosh.dixit@intel.com> <91876d66-5ba8-0351-583e-8baf1ff4a1e1@intel.com> <87v9mpsjqp.wl-ashutosh.dixit@intel.com> <199e0a58-95d0-f88f-efef-12d59bacdd76@intel.com> <87r1xdshml.wl-ashutosh.dixit@intel.com> <87lfnhm52d.wl-ashutosh.dixit@intel.com> From: Lionel Landwerlin Message-ID: <5fdba63f-3e17-7b20-663b-ffbe08294235@intel.com> Date: Tue, 31 Mar 2020 10:36:54 +0300 MIME-Version: 1.0 In-Reply-To: <87lfnhm52d.wl-ashutosh.dixit@intel.com> Content-Language: en-US Subject: Re: [igt-dev] [PATCH i-g-t] tests/perf: add a test for OA data polling reads using "small" buffers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" To: "Dixit, Ashutosh" Cc: igt-dev@lists.freedesktop.org List-ID: On 31/03/2020 09:06, Dixit, Ashutosh wrote: > On Fri, 27 Mar 2020 12:49:22 -0700, Dixit, Ashutosh wrote: >> On Fri, 27 Mar 2020 12:06:13 -0700, Lionel Landwerlin wrote: >>> On 27/03/2020 21:03, Dixit, Ashutosh wrote: >>>> On Fri, 27 Mar 2020 09:09:41 -0700, Lionel Landwerlin wrote: >>>>> On 27/03/2020 06:50, Dixit, Ashutosh wrote: >>>>>> On Thu, 26 Mar 2020 21:42:50 -0700, Ashutosh Dixit wrote: >>>>>>> diff --git a/tests/perf.c b/tests/perf.c >>>>>>> index 724f6f809..3dc757c3b 100644 >>>>>>> --- a/tests/perf.c >>>>>>> +++ b/tests/perf.c >>>>>>> +static void test_polling_small_buf(void) >>>>>>> +{ >>>>>> /snip/ >>>>>> >>>>>>> + >>>>>>> + igt_assert(abs(n_expect_read_bytes - n_bytes_read) < (0.10 * n_expect_read_bytes)); >>>>>>> +} >>>>>>> + >>>>>> I'd be wary of a 90% match on slow platforms like Atom? Maybe 80% is safer? >>>>> Do we have any experiment showing them behaving differently? >>>> No I don't have any data, but considering that in previous stable versions >>>> we can only read < 10% of the data, I think it should be ok to go down to >>>> 80%? So that we don't start getting unnecessary false alarms in CI, even >>>> when the issue is fixed. >>> Okay, for the record I get somewhere between 93~95% of expected reports on >>> KBLGT2. >> Yes I tried it and saw that. I already gave a R-b so we could probably >> merge the patch after making that change (0.2 instead of 0.1 above), or do >> you want me to post a new version with the change? Thanks! > Actually there has been some change in the kernel, earlier like you I was > also getting around 94% with a 1 KB buffer, now I am getting about > 87%. I am getting 94% with a 1 MB buffer. Does the amount of expected data > in the test need to be modified? I can try to bisect tomorrow and see what > has done this, unless you already know. Thanks! Ah, that's probably the read() bug you're fixing... Are you running with the kernel patch : "drm/i915/perf: Do not clear pollin for small user read buffers" ? -Lionel _______________________________________________ igt-dev mailing list igt-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/igt-dev