<!DOCTYPE html><html><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body> On 4/4/2024 21:47, Upadhyay, Tejas wrote: <blockquote type="cite" cite="mid:SJ1PR11MB6204AA1AFB30BFEF7EBAA3D281032@SJ1PR11MB6204.namprd11.prod.outlook.com"> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">-----Original Message----- From: Harrison, John C <a class="moz-txt-link-rfc2396E" href="mailto:john.c.harrison@intel.com"><john.c.harrison@intel.com></a> Sent: Friday, April 5, 2024 4:53 AM To: Upadhyay, Tejas <a class="moz-txt-link-rfc2396E" href="mailto:tejas.upadhyay@intel.com"><tejas.upadhyay@intel.com></a>; De Marchi, Lucas <a class="moz-txt-link-rfc2396E" href="mailto:lucas.demarchi@intel.com"><lucas.demarchi@intel.com></a>; Roper, Matthew D <a class="moz-txt-link-rfc2396E" href="mailto:matthew.d.roper@intel.com"><matthew.d.roper@intel.com></a> Cc: <a class="moz-txt-link-abbreviated" href="mailto:igt-dev@lists.freedesktop.org">igt-dev@lists.freedesktop.org</a>; <a class="moz-txt-link-abbreviated" href="mailto:intel-xe@lists.freedesktop.org">intel-xe@lists.freedesktop.org</a>; Brost, Matthew <a class="moz-txt-link-rfc2396E" href="mailto:matthew.brost@intel.com"><matthew.brost@intel.com></a> Subject: Re: [PATCH V2 i-g-t] tests/xe_exec_threads: Make hang tests reset domain aware On 4/2/2024 22:35, Upadhyay, Tejas wrote: </pre> <blockquote type="cite"> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">-----Original Message----- From: De Marchi, Lucas <a class="moz-txt-link-rfc2396E" href="mailto:lucas.demarchi@intel.com"><lucas.demarchi@intel.com></a> Sent: Wednesday, April 3, 2024 2:26 AM To: Roper, Matthew D <a class="moz-txt-link-rfc2396E" href="mailto:matthew.d.roper@intel.com"><matthew.d.roper@intel.com></a> Cc: Upadhyay, Tejas <a class="moz-txt-link-rfc2396E" href="mailto:tejas.upadhyay@intel.com"><tejas.upadhyay@intel.com></a>; igt- <a class="moz-txt-link-abbreviated" href="mailto:dev@lists.freedesktop.org">dev@lists.freedesktop.org</a>; <a class="moz-txt-link-abbreviated" href="mailto:intel-xe@lists.freedesktop.org">intel-xe@lists.freedesktop.org</a>; Brost, Matthew <a class="moz-txt-link-rfc2396E" href="mailto:matthew.brost@intel.com"><matthew.brost@intel.com></a> Subject: Re: [PATCH V2 i-g-t] tests/xe_exec_threads: Make hang tests reset domain aware On Tue, Apr 02, 2024 at 12:40:17PM -0700, Matt Roper wrote: </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">On Tue, Apr 02, 2024 at 05:52:23PM +0530, Tejas Upadhyay wrote: </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">RCS/CCS are dependent engines as they are sharing reset domain. Whenever there is reset from CCS, all the exec queues running on RCS are victimised mainly on Lunarlake. Lets skip parallel execution on CCS with RCS. </pre> </blockquote> <pre class="moz-quote-pre" wrap="">I haven't really looked at this specific test in detail, but based on your explanation here, you're also going to run into problems with multiple CCS engines since they all share the same reset. You won't see that on platforms like LNL that only have a single CCS, but platforms </pre> </blockquote> <pre class="moz-quote-pre" wrap="">but it is seen on LNL because of having both RCS and CCS. </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">like PVC, ATS-M, DG2, etc. can all have multiple CCS where a reset on one kills anything running on the others. Matt </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">It helps in fixing following errors: 1. Test assertion failure function test_legacy_mode, file, Failed assertion: data[i].data == 0xc0ffee 2.Test assertion failure function xe_exec, file ../lib/xe/xe_ioctl.c, Failed assertion: __xe_exec(fd, exec) == 0, error: -125 != 0 Signed-off-by: Tejas Upadhyay <a class="moz-txt-link-rfc2396E" href="mailto:tejas.upadhyay@intel.com"><tejas.upadhyay@intel.com></a> --- tests/intel/xe_exec_threads.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/tests/intel/xe_exec_threads.c b/tests/intel/xe_exec_threads.c index 8083980f9..31af61dc9 100644 --- a/tests/intel/xe_exec_threads.c +++ b/tests/intel/xe_exec_threads.c @@ -710,6 +710,17 @@ static void *thread(void *data) return NULL; } +static bool is_engine_contexts_victimized(int fd, unsigned int +flags) { + if (!IS_LUNARLAKE(intel_get_drm_devid(fd))) + return false; </pre> </blockquote> </blockquote> <pre class="moz-quote-pre" wrap="">as above, I don't think we should add any platform check here. It's impossible to keep it up to date and it's also testing the wrong thing. AFAIU you don't want parallel submission on engines that share the same reset domain. So, this is actually what should be tested. </pre> </blockquote> <pre class="moz-quote-pre" wrap="">Platforms like PVC, ATS-M, DG2, etc. have some kind of WA/noWA which </pre> </blockquote> <pre class="moz-quote-pre" wrap="">helps to run things parallelly on engines in same reset domain and apparently BMG/LNL does not have that kind of support so applicable for LNL/BMG with parallel submission on RCS/CCS only. </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap=""> @Harrison, John C please reply if you have any other input here. </pre> </blockquote> <pre class="moz-quote-pre" wrap="">I don't get what you mean by 'have some kind of WA/noWA'. All platforms with compute engines have shared reset domains. That is all there is to it. I.e. everything from TGL onwards. That includes RCS and all CCS engines. So RCS + CCS, CCS0 + CCS1, RCS + CC0 + CCS1, etc. Any platform with multiple engines that talk to EUs will reset all of those engines in parallel. There are w/a's which make the situation even worse. E.g. on DG2/MTL you are not allowed to context switch one of those engines while another is busy. Which means that if one hangs, they all hang - you cannot just wait for other workloads to complete and/or pre-empt them off the engine prior to doing the shared reset. But there is nothing that makes it better. I assume we are talking about GuC triggered engine resets here? As opposed to driver triggered full GT resets? The GuC will attempt to idle all other connected engines first by pre-empting out any executing contexts. If those contexts are pre-emptible then they will survive - GuC will automatically restart them once the reset is complete. If they are not (or at least not pre-emptible within the pre-emption timeout limit) then they will be killed as collateral damage. What are the workloads being submitted by this test? Are the pre-emptible spinners? If so, then they should survive (assuming you don't have the DG2/MTL RCS/CCS w/a in effect). If they are non-preemptible spinners then they are toast. </pre> </blockquote> <pre class="moz-quote-pre" wrap=""> Main question here was, if this fix should be applied to all platforms who has RCS and CCS both or just LNL/BMG. Reason to ask is, only LNL/BMG are hitting this issue, with same tests PVC and other platforms are not hitting issue which we are addressing here.</pre> </blockquote> And the answer is that yes, shared reset domains are common to all platforms with compute engines. So if only LNL/BMG are failing then the problem is not understood. Which is not helped by this test code being extremely complex and having almost zero explanation in it at all :(. As noted, PVC has multiple compute engines but no RCS engine. If any compute engine is reset then all are reset. So if the test is running correctly and passing on PVC then it cannot be failing on LNL/BMG purely due to shared domain resets. Is the reset not happening on PVC? Is the test not actually running multiple contexts in parallel on PVC? Or are the spinners pre-emptible and are therefore supposed to survive the reset of a shared domain engine by being swapped out first? In which case LNL/BMG are broken because the killed contexts are not supposed to be killed even though the engine is reset? John. <blockquote type="cite" cite="mid:SJ1PR11MB6204AA1AFB30BFEF7EBAA3D281032@SJ1PR11MB6204.namprd11.prod.outlook.com"> <pre class="moz-quote-pre" wrap=""> Thanks, Tejas </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap=""> John. </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap=""> Thanks, Tejas </pre> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">Lucas De Marchi </pre> <blockquote type="cite"> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">+ + if (flags & HANG) + return true; + + return false; +} + /** * SUBTEST: threads-%s * Description: Run threads %arg[1] test with multi threads @@ -955,9 +966,13 @@ static void threads(int fd, int flags) bool go = false; int n_threads = 0; int gt; + bool has_rcs = false; - xe_for_each_engine(fd, hwe) + xe_for_each_engine(fd, hwe) { + if (hwe->engine_class == DRM_XE_ENGINE_CLASS_RENDER) + has_rcs = true; ++n_engines; + } if (flags & BALANCER) { xe_for_each_gt(fd, gt) @@ -990,6 +1005,15 @@ static void threads(int fd, int flags) } xe_for_each_engine(fd, hwe) { + /* RCS/CCS sharing reset domain hence dependent engines. + * When CCS is doing reset, all the contexts of RCS are + * victimized, so skip the compute engine avoiding + * parallel execution with RCS + */ + if (has_rcs && hwe->engine_class == </pre> </blockquote> </blockquote> <pre class="moz-quote-pre" wrap="">DRM_XE_ENGINE_CLASS_COMPUTE && </pre> <blockquote type="cite"> <blockquote type="cite"> <pre class="moz-quote-pre" wrap="">+ is_engine_contexts_victimized(fd, flags)) + continue; + threads_data[i].mutex = &mutex; threads_data[i].cond = &cond; #define ADDRESS_SHIFT 39 -- 2.25.1 </pre> </blockquote> <pre class="moz-quote-pre" wrap="">-- Matt Roper Graphics Software Engineer Linux GPU Platform Enablement Intel Corporation </pre> </blockquote> </blockquote> </blockquote> </blockquote> <pre class="moz-quote-pre" wrap=""> </pre> </blockquote> </body> </html>