From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [Dovetail] x86 test version available (kernel v5.10) References: <874kixxf9e.fsf@xenomai.org> <87k0rprr5a.fsf@xenomai.org> <46e13cc0-6f1c-65f3-34cc-4a6ea44d00d8@siemens.com> <5a957790-9b3e-4df1-e0e8-96fa4e92e1eb@siemens.com> From: Jan Kiszka Message-ID: <1346fbeb-63b6-4f29-e91d-deb1f200a195@siemens.com> Date: Mon, 15 Feb 2021 18:19:47 +0100 MIME-Version: 1.0 In-Reply-To: <5a957790-9b3e-4df1-e0e8-96fa4e92e1eb@siemens.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum Cc: xenomai@xenomai.org On 15.02.21 17:53, Jan Kiszka via Xenomai wrote: > On 15.02.21 16:11, Jan Kiszka via Xenomai wrote: >> On 15.02.21 14:28, Jan Kiszka wrote: >>> Now the next issue is >>> >>> /usr/lib/xenomai/testsuite/smokey: test sched_quota failed: Protocol error >>> sched-quota.c:332, out of quota: 13.7% >>> (on a real target, an Atom-class box). >>> >> >> Testsuite issue, long pending: >> >> https://gitlab.denx.de/Xenomai/xenomai/-/blob/master/testsuite/smokey/sched-quota/sched-quota.c#L204 >> >> Those pthread_kill() in the loop will kick the caller into non-rt, while >> it is not yet done with collecting the loop counters from the other >> workers. Result is pure random, sometimes still within the defined >> limits, but sometimes reporting false overruns. >> >> No idea what those signal submissions supposed to do - test runs and >> terminates fine without them as well. >> > > Correction: The pthread_kill stay in primary and do not cause the issue > (they are still not needed IMHO, though). > > It must be something compiler (setting?) related: smokey built with my > gcc-7 from SUSE is fine, the one build with Debian's gcc-8 is not, > causing noteworthy variations on the measured workload. Examining further... > It was gcc-10 in fact on my machine - but the actual difference was --enable-debug=full here vs. no debug in xenomai-images. Without full debugging, the loop calibration becomes too instable, likely because the inner __do_work is reduced to a simple 417960: 48 8d 47 01 lea 0x1(%rdi),%rax 417964: c3 retq This can be mitigated by extending the calibration loop (crunch_loops = 100000). Jan -- Siemens AG, T RDA IOT Corporate Competence Center Embedded Linux