From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Stancek Date: Tue, 12 Dec 2017 10:04:33 -0500 (EST) Subject: [LTP] [PATCH V3] ltp: Add a zero latency constraint for the timer tests library In-Reply-To: References: <20170817135029.GA31322@rei> <1502982026-4113-1-git-send-email-daniel.lezcano@linaro.org> <20170818122533.GD22319@rei.lan> <1864131650.54048676.1513090088938.JavaMail.zimbra@redhat.com> Message-ID: <1566390724.54053292.1513091073892.JavaMail.zimbra@redhat.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable To: ltp@lists.linux.it ----- Original Message ----- > On 12/12/2017 15:48, Jan Stancek wrote: > > Hi, > >=20 > > I'm running into similar problem on "Dell Precision 5820 tower", with > > Intel(R) Xeon(R) W-2133 CPU @ 3.60GHz, but I can't find any /proc /sys > > knob that would help. > >=20 > > # uname -r > > 4.14.5 > >=20 > > # cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor > > performance > > performance > > performance > > performance > > performance > > performance > > performance > > performance > > performance > > performance > > performance > > performance > >=20 > > Any timer related tests are reliably failing on longer timeouts: > > --- > > tst_test.c:934: INFO: Timeout per run is 0h 05m 00s > > tst_timer_test.c:356: INFO: CLOCK_MONOTONIC resolution 1ns > > tst_timer_test.c:368: INFO: prctl(PR_GET_TIMERSLACK) =3D 50us > > tst_timer_test.c:275: INFO: poll() sleeping for 1000us 500 iterations, > > threshold 450.01us > > tst_timer_test.c:318: INFO: min 1095us, max 1098us, median 1096us, trunc > > mean 1095.99us (discarded 25) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 2000us 500 iterations, > > threshold 450.01us > > tst_timer_test.c:318: INFO: min 2062us, max 2138us, median 2137us, trunc > > mean 2135.98us (discarded 25) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 5000us 300 iterations, > > threshold 450.04us > > tst_timer_test.c:318: INFO: min 5262us, max 5263us, median 5262us, trunc > > mean 5262.20us (discarded 15) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 10000us 100 iterations, > > threshold 450.33us > > tst_timer_test.c:318: INFO: min 10318us, max 10471us, median 10471us, t= runc > > mean 10469.07us (discarded 5) > > tst_timer_test.c:321: FAIL: poll() slept for too long >=20 > Are you running the tests with this zero latency patch included ? Yes, I'm running ltp release 20170929, which has your patch. ... [pid 18276] 09:59:21.379883 open("/dev/cpu_dma_latency", O_WRONLY) =3D 3 [pid 18276] 09:59:21.379906 write(3, "\0\0\0\0", 4) =3D 4 ... I tried it without that patch, and it started failing more with smaller timeouts. Regards, Jan >=20 >=20 > > SCHED_OTHER or SCHED_FIFO -> FAIL > > intel_idle.max_cstate=3D0 processor.max_cstate=3D1 -> FAIL > > echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo -> FAIL > > idle=3Dhalt -> FAIL > > idle=3Dpoll -> FAIL > >=20 > > Only thing I found to help is to keep CPU slightly busy with > > taskset -c 1 sh -c "while [ True ]; do usleep 100; done" > >=20 > > After that it started to PASS: > >=20 > > # taskset -c 1 ./poll02 > > tst_test.c:934: INFO: Timeout per run is 0h 05m 00s > > tst_timer_test.c:356: INFO: CLOCK_MONOTONIC resolution 1ns > > tst_timer_test.c:368: INFO: prctl(PR_GET_TIMERSLACK) =3D 50us > > tst_timer_test.c:275: INFO: poll() sleeping for 1000us 500 iterations, > > threshold 450.01us > > tst_timer_test.c:318: INFO: min 1004us, max 1325us, median 1072us, trunc > > mean 1149.29us (discarded 25) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 2000us 500 iterations, > > threshold 450.01us > > tst_timer_test.c:318: INFO: min 2007us, max 2326us, median 2075us, trunc > > mean 2158.64us (discarded 25) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 5000us 300 iterations, > > threshold 450.04us > > tst_timer_test.c:318: INFO: min 5006us, max 5345us, median 5074us, trunc > > mean 5146.84us (discarded 15) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 10000us 100 iterations, > > threshold 450.33us > > tst_timer_test.c:318: INFO: min 10004us, max 10364us, median 10075us, t= runc > > mean 10128.61us (discarded 5) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 25000us 50 iterations, > > threshold 451.29us > > tst_timer_test.c:318: INFO: min 25006us, max 25359us, median 25072us, t= runc > > mean 25137.48us (discarded 2) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 100000us 10 iterations, > > threshold 537.00us > > tst_timer_test.c:318: INFO: min 100010us, max 100372us, median 100125us, > > trunc mean 100167.78us (discarded 1) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > > tst_timer_test.c:275: INFO: poll() sleeping for 1000000us 2 iterations, > > threshold 4400.00us > > tst_timer_test.c:318: INFO: min 1000843us, max 1000920us, median 100084= 3us, > > trunc mean 1000843.00us (discarded 1) > > tst_timer_test.c:333: PASS: Measured times are within thresholds > >=20 > > Summary: > > passed 7 > > failed 0 > > skipped 0 > > warnings 0 > >=20 > > Any ideas? > >=20 > > Regards, > > Jan > >=20 >=20 >=20 > -- > Linaro.org =E2=94=82 Open source software for A= RM SoCs >=20 > Follow Linaro: Facebook | > Twitter | > Blog >=20 >=20 > -- > Mailing list info: https://lists.linux.it/listinfo/ltp >=20