* [Xenomai] high latency with imx6q without smp @ 2013-10-01 12:24 Roberto Bielli 2013-10-01 12:26 ` Gilles Chanteperdrix 0 siblings, 1 reply; 9+ messages in thread From: Roberto Bielli @ 2013-10-01 12:24 UTC (permalink / raw) To: xenomai@xenomai.org, Gilles Chanteperdrix Hi, i try to disable smp in the kernel for working with a single cpu on a imx6q but i saw a very high max latency with the test ( /usr/xenomai/bin/latency ), about ~350us. Any ideas to reduce the latency? Is the patch 3.0.43 for imx6q available without smp ? -- +------------------------------------------------------------------------------------------------+ Roberto Bielli Sviluppo Software Axel S.r.l. Via Del Cannino, 3 21020 Crosio Della Valle Varese - Italy Telefono: +39 0332 949600 Fax: +39 0332 969315 E-mail: roberto.bielli@axelsw.it Web Site: www.axelsw.it +------------------------------------------------------------------------------------------------+ Si precisa che le informazioni contenute in questo messaggio sono riservate e ad uso esclusivo del destinatario. Qualora il messaggio in parola Le fosse pervenuto per errore, La preghiamo di eliminarlo senza copiarlo e di non inoltrarlo a terzi, dandocene gentilmente comunicazione. Grazie. Informativa sul trattamento dei dati personali (D. Lgs. 196/2003). I dati utilizzati per la spedizione del presente messaggio sono utilizzati da Axel S.r.l., titolare del trattamento, per l'invio delle comunicazioni dei diversi settori aziendali, non essendo autorizzata la divulgazione a terzi. Potrete rivolgere alla seguente mail richieste di verifica, rettifica o cancellazione dei Vostri dati: info@axelsw.it This e-mail and any attachments is confidential and may contain privileged information intended for the addressee(s) only. Dissemination, copying, printing or use by anybody else is unauthorised. If you are not the intended recipient, please delete this message and any attachments and advise the sender by return e-mail.Thank you. +------------------------------------------------------------------------------------------------+ ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Xenomai] high latency with imx6q without smp 2013-10-01 12:24 [Xenomai] high latency with imx6q without smp Roberto Bielli @ 2013-10-01 12:26 ` Gilles Chanteperdrix 2013-10-01 12:50 ` Roberto Bielli 0 siblings, 1 reply; 9+ messages in thread From: Gilles Chanteperdrix @ 2013-10-01 12:26 UTC (permalink / raw) To: Roberto Bielli; +Cc: xenomai@xenomai.org Roberto Bielli wrote: > Hi, > > i try to disable smp in the kernel for working with a single cpu on a > imx6q but i saw a very high max latency with the test ( > /usr/xenomai/bin/latency ), about ~350us. > Any ideas to reduce the latency? See my previous detailed answer about this question. You seem to have a habit of disregarding the answers you receive and ask the same question again. You should understand it does not motivate people to continue answering you. > > Is the patch 3.0.43 for imx6q available without smp ? Always the same answer, can you not test before asking, and only ask if you have an issue? -- Gilles ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Xenomai] high latency with imx6q without smp 2013-10-01 12:26 ` Gilles Chanteperdrix @ 2013-10-01 12:50 ` Roberto Bielli 2013-10-01 19:10 ` Gilles Chanteperdrix 0 siblings, 1 reply; 9+ messages in thread From: Roberto Bielli @ 2013-10-01 12:50 UTC (permalink / raw) Cc: xenomai@xenomai.org Hi, excuse me for the previous question i have not seen your email. i have tried the kernel with the ipipe patch 3.0.43 on xenomai 2.6.x branch without smp and has very high worst latency: RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst RTD| 5.999| 11.333| 25.333| 0| 0| 5.666| 328.999 RTD| 10.999| 11.333| 19.666| 0| 0| 5.666| 328.999 RTD| 5.999| 10.999| 17.999| 0| 0| 5.666| 328.999 RTD| 10.999| 11.333| 17.999| 0| 0| 5.666| 328.999 RTD| 5.999| 11.333| 26.999| 0| 0| 5.666| 328.999 This behaviour isn't in smp version with 2 processors. So i read your email and if i understand correctly could be the L2 cache spinlock that create large latencies (?328.999). I'm not using framebuffer directly. You told me that there is a patch that can fix this behaviour in the last ipipe patch. is there a commit for fixing only this behaviour that i can move on my kernel with patch 3.0.43 ? Il 01/10/2013 14:26, Gilles Chanteperdrix ha scritto: > Roberto Bielli wrote: >> Hi, >> >> i try to disable smp in the kernel for working with a single cpu on a >> imx6q but i saw a very high max latency with the test ( >> /usr/xenomai/bin/latency ), about ~350us. >> Any ideas to reduce the latency? > See my previous detailed answer about this question. You seem to have a > habit of disregarding the answers you receive and ask the same question > again. You should understand it does not motivate people to continue > answering you. > >> Is the patch 3.0.43 for imx6q available without smp ? > Always the same answer, can you not test before asking, and only ask if > you have an issue? > -- +------------------------------------------------------------------------------------------------+ Roberto Bielli Sviluppo Software Axel S.r.l. Via Del Cannino, 3 21020 Crosio Della Valle Varese - Italy Telefono: +39 0332 949600 Fax: +39 0332 969315 E-mail: roberto.bielli@axelsw.it Web Site: www.axelsw.it +------------------------------------------------------------------------------------------------+ Si precisa che le informazioni contenute in questo messaggio sono riservate e ad uso esclusivo del destinatario. Qualora il messaggio in parola Le fosse pervenuto per errore, La preghiamo di eliminarlo senza copiarlo e di non inoltrarlo a terzi, dandocene gentilmente comunicazione. Grazie. Informativa sul trattamento dei dati personali (D. Lgs. 196/2003). I dati utilizzati per la spedizione del presente messaggio sono utilizzati da Axel S.r.l., titolare del trattamento, per l'invio delle comunicazioni dei diversi settori aziendali, non essendo autorizzata la divulgazione a terzi. Potrete rivolgere alla seguente mail richieste di verifica, rettifica o cancellazione dei Vostri dati: info@axelsw.it This e-mail and any attachments is confidential and may contain privileged information intended for the addressee(s) only. Dissemination, copying, printing or use by anybody else is unauthorised. If you are not the intended recipient, please delete this message and any attachments and advise the sender by return e-mail.Thank you. +------------------------------------------------------------------------------------------------+ ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Xenomai] high latency with imx6q without smp 2013-10-01 12:50 ` Roberto Bielli @ 2013-10-01 19:10 ` Gilles Chanteperdrix 2013-10-03 8:36 ` Roberto Bielli 0 siblings, 1 reply; 9+ messages in thread From: Gilles Chanteperdrix @ 2013-10-01 19:10 UTC (permalink / raw) To: Roberto Bielli; +Cc: xenomai@xenomai.org On 10/01/2013 02:50 PM, Roberto Bielli wrote: > Hi, > > excuse me for the previous question i have not seen your email. > i have tried the kernel with the ipipe patch 3.0.43 on xenomai 2.6.x > branch without smp and has very high worst latency: > RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat > best|--lat worst > RTD| 5.999| 11.333| 25.333| 0| 0| 5.666| 328.999 > RTD| 10.999| 11.333| 19.666| 0| 0| 5.666| 328.999 > RTD| 5.999| 10.999| 17.999| 0| 0| 5.666| 328.999 > RTD| 10.999| 11.333| 17.999| 0| 0| 5.666| 328.999 > RTD| 5.999| 11.333| 26.999| 0| 0| 5.666| 328.999 > > This behaviour isn't in smp version with 2 processors. It may be here in SMP but you do not see it. You should run the latency test under load to try and trigger the worst case latency. > > So i read your email and if i understand correctly could be the L2 cache > spinlock that create large latencies (?328.999). The L2 cache spinlock section are alreay reduced, the maximum was rather around 40us anyway. > I'm not using framebuffer directly. > You told me that there is a patch that can fix this behaviour in the > last ipipe patch. > is there a commit for fixing only this behaviour that i can move on my > kernel with patch 3.0.43 ? Please try disabling the framebuffer driver completely, and see if it changes anything. If it does not change anything, you have to use the I-pipe tracer. -- Gilles. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Xenomai] high latency with imx6q without smp 2013-10-01 19:10 ` Gilles Chanteperdrix @ 2013-10-03 8:36 ` Roberto Bielli 2013-10-03 13:27 ` Gilles Chanteperdrix 0 siblings, 1 reply; 9+ messages in thread From: Roberto Bielli @ 2013-10-03 8:36 UTC (permalink / raw) To: Gilles Chanteperdrix; +Cc: xenomai@xenomai.org Hi, i reduced drastically the latency disabling the cpu frequency scaling -> CONFIG_CPU_FREQ ( max 25us ). Il 01/10/2013 21:10, Gilles Chanteperdrix ha scritto: > On 10/01/2013 02:50 PM, Roberto Bielli wrote: >> Hi, >> >> excuse me for the previous question i have not seen your email. >> i have tried the kernel with the ipipe patch 3.0.43 on xenomai 2.6.x >> branch without smp and has very high worst latency: >> RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat >> best|--lat worst >> RTD| 5.999| 11.333| 25.333| 0| 0| 5.666| 328.999 >> RTD| 10.999| 11.333| 19.666| 0| 0| 5.666| 328.999 >> RTD| 5.999| 10.999| 17.999| 0| 0| 5.666| 328.999 >> RTD| 10.999| 11.333| 17.999| 0| 0| 5.666| 328.999 >> RTD| 5.999| 11.333| 26.999| 0| 0| 5.666| 328.999 >> >> This behaviour isn't in smp version with 2 processors. > It may be here in SMP but you do not see it. You should run the latency > test under load to try and trigger the worst case latency. > >> So i read your email and if i understand correctly could be the L2 cache >> spinlock that create large latencies (?328.999). > The L2 cache spinlock section are alreay reduced, the maximum was rather > around 40us anyway. > >> I'm not using framebuffer directly. >> You told me that there is a patch that can fix this behaviour in the >> last ipipe patch. >> is there a commit for fixing only this behaviour that i can move on my >> kernel with patch 3.0.43 ? > Please try disabling the framebuffer driver completely, and see if it > changes anything. If it does not change anything, you have to use the > I-pipe tracer. > -- +------------------------------------------------------------------------------------------------+ Roberto Bielli Sviluppo Software Axel S.r.l. Via Del Cannino, 3 21020 Crosio Della Valle Varese - Italy Telefono: +39 0332 949600 Fax: +39 0332 969315 E-mail: roberto.bielli@axelsw.it Web Site: www.axelsw.it +------------------------------------------------------------------------------------------------+ Si precisa che le informazioni contenute in questo messaggio sono riservate e ad uso esclusivo del destinatario. Qualora il messaggio in parola Le fosse pervenuto per errore, La preghiamo di eliminarlo senza copiarlo e di non inoltrarlo a terzi, dandocene gentilmente comunicazione. Grazie. Informativa sul trattamento dei dati personali (D. Lgs. 196/2003). I dati utilizzati per la spedizione del presente messaggio sono utilizzati da Axel S.r.l., titolare del trattamento, per l'invio delle comunicazioni dei diversi settori aziendali, non essendo autorizzata la divulgazione a terzi. Potrete rivolgere alla seguente mail richieste di verifica, rettifica o cancellazione dei Vostri dati: info@axelsw.it This e-mail and any attachments is confidential and may contain privileged information intended for the addressee(s) only. Dissemination, copying, printing or use by anybody else is unauthorised. If you are not the intended recipient, please delete this message and any attachments and advise the sender by return e-mail.Thank you. +------------------------------------------------------------------------------------------------+ ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Xenomai] high latency with imx6q without smp 2013-10-03 8:36 ` Roberto Bielli @ 2013-10-03 13:27 ` Gilles Chanteperdrix 2013-10-03 13:33 ` Drasko DRASKOVIC 0 siblings, 1 reply; 9+ messages in thread From: Gilles Chanteperdrix @ 2013-10-03 13:27 UTC (permalink / raw) To: Roberto Bielli; +Cc: xenomai@xenomai.org On 10/03/2013 10:36 AM, Roberto Bielli wrote: > Hi, > > i reduced drastically the latency disabling the cpu frequency scaling -> > CONFIG_CPU_FREQ ( max 25us ). This seems a bit too good to be true. Chances are higher to approach the real worst case latency on a system under load. -- Gilles. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Xenomai] high latency with imx6q without smp 2013-10-03 13:27 ` Gilles Chanteperdrix @ 2013-10-03 13:33 ` Drasko DRASKOVIC 2013-10-03 13:51 ` Roberto Bielli 0 siblings, 1 reply; 9+ messages in thread From: Drasko DRASKOVIC @ 2013-10-03 13:33 UTC (permalink / raw) To: Gilles Chanteperdrix; +Cc: xenomai@xenomai.org On Thu, Oct 3, 2013 at 3:27 PM, Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> wrote: > On 10/03/2013 10:36 AM, Roberto Bielli wrote: >> Hi, >> >> i reduced drastically the latency disabling the cpu frequency scaling -> >> CONFIG_CPU_FREQ ( max 25us ). > > This seems a bit too good to be true. Chances are higher to approach the > real worst case latency on a system under load. Can xeno-test give good and reliable figures for this case? BR, Drasko ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Xenomai] high latency with imx6q without smp 2013-10-03 13:33 ` Drasko DRASKOVIC @ 2013-10-03 13:51 ` Roberto Bielli 2013-10-03 14:07 ` Gilles Chanteperdrix 0 siblings, 1 reply; 9+ messages in thread From: Roberto Bielli @ 2013-10-03 13:51 UTC (permalink / raw) To: Drasko DRASKOVIC, Gilles Chanteperdrix; +Cc: xenomai@xenomai.org Hi, the results of xeno-test are these. When i execute the xeno-test i run simultaneously a telnet with an 'ls -lr /' for increase etherne interrupts. /usr/xenomai/bin/xeno-test Started child 3089: /bin/sh /usr/xenomai/bin/xeno-test-run-wrapper /usr/xenomai/ bin/xeno-test [[43]+echo 0 [[45]+/usr/xenomai/bin/arith mul: 0x79364d93, shft: 26 integ: 30, frac: 0x4d9364d9364d9364 signed positive operation: 0x03ffffffffffffff * 1000000000 / 33000000 inline calibration: 0x0000000000000000: 350.233 ns, rejected 1/10000 inlined llimd: 0x79364d9364d9362f: 1443.833 ns, rejected 5/10000 inlined llmulshft: 0x79364d92ffffffe1: 25.233 ns, rejected 2/10000 inlined nodiv_llimd: 0x79364d9364d9362f: 46.333 ns, rejected 0/10000 out of line calibration: 0x0000000000000000: 359.866 ns, rejected 2/10000 out of line llimd: 0x79364d9364d9362f: 1445.400 ns, rejected 7/10000 out of line llmulshft: 0x79364d92ffffffe1: 21.133 ns, rejected 0/10000 out of line nodiv_llimd: 0x79364d9364d9362f: 35.666 ns, rejected 1/10000 signed negative operation: 0xfc00000000000001 * 1000000000 / 33000000 inline calibration: 0x0000000000000000: 348.999 ns, rejected 4/10000 inlined llimd: 0x86c9b26c9b26c9d1: 1456.033 ns, rejected 2/10000 inlined llmulshft: 0x86c9b26d0000001e: 30.433 ns, rejected 1/10000 inlined nodiv_llimd: 0x86c9b26c9b26c9d1: 46.266 ns, rejected 1/10000 out of line calibration: 0x0000000000000000: 360.933 ns, rejected 0/10000 out of line llimd: 0x86c9b26c9b26c9d1: 1444.900 ns, rejected 7/10000 out of line llmulshft: 0x86c9b26d0000001e: 18.733 ns, rejected 1/10000 out of line nodiv_llimd: 0x86c9b26c9b26c9d1: 34.733 ns, rejected 0/10000 unsigned operation: 0x03ffffffffffffff * 1000000000 / 33000000 inline calibration: 0x0000000000000000: 350.833 ns, rejected 2/10000 inlined nodiv_ullimd: 0x79364d9364d9362f: 44.333 ns, rejected 0/10000 out of line calibration: 0x0000000000000000: 359.466 ns, rejected 1/10000 out of line nodiv_ullimd: 0x79364d9364d9362f: 36.366 ns, rejected 0/10000 [[46]+/usr/xenomai/bin/clocktest -C 42 -T 30 == Tested clock: 42 (CLOCK_HOST_REALTIME) CPU ToD offset [us] ToD drift [us/s] warps max delta [us] --- -------------------- ---------------- ---------- -------------- 0 1.5 0.011 0 0.0 [[47]+/usr/xenomai/bin/switchtest -T 30 == Testing FPU check routines... d0: 1 != 2 d1: 1 != 2 d2: 1 != 2 d3: 1 != 2 d4: 1 != 2 d5: 1 != 2 d6: 1 != 2 d7: 1 != 2 d8: 1 != 2 d9: 1 != 2 d10: 1 != 2 d11: 1 != 2 d12: 1 != 2 d13: 1 != 2 d14: 1 != 2 d15: 1 != 2 == FPU check routines: OK. == Threads: sleeper_ufps0-0 rtk0-1 rtk0-2 rtk_fp0-3 rtk_fp0-4 rtk_fp_ufpp0-5 rtk _fp_ufpp0-6 rtup0-7 rtup0-8 rtup_ufpp0-9 rtup_ufpp0-10 rtus0-11 rtus0-12 rtus_uf ps0-13 rtus_ufps0-14 rtuo0-15 rtuo0-16 rtuo_ufpp0-17 rtuo_ufpp0-18 rtuo_ufps0-19 rtuo_ufps0-20 rtuo_ufpp_ufps0-21 rtuo_ufpp_ufps0-22 RTT| 00:00:01 RTH|---------cpu|ctx switches|-------total RTD| 0| 16629| 16629 RTD| 0| 16698| 33327 RTD| 0| 16765| 50092 RTD| 0| 16976| 67068 RTD| 0| 16903| 83971 RTD| 0| 16767| 100738 RTD| 0| 16838| 117576 RTD| 0| 16700| 134276 RTD| 0| 16765| 151041 RTD| 0| 16698| 167739 RTD| 0| 16696| 184435 RTD| 0| 16840| 201275 RTD| 0| 17039| 218314 RTD| 0| 16840| 235154 RTD| 0| 16901| 252055 RTD| 0| 16769| 268824 RTD| 0| 16696| 285520 RTD| 0| 16767| 302287 RTD| 0| 16698| 318985 RTD| 0| 16702| 335687 RTD| 0| 16974| 352661 RTT| 00:00:22 RTH|---------cpu|ctx switches|-------total RTD| 0| 16901| 369562 RTD| 0| 16840| 386402 RTD| 0| 16903| 403305 RTD| 0| 16700| 420005 RTD| 0| 16763| 436768 RTD| 0| 16767| 453535 RTD| 0| 16700| 470235 RTD| 0| 16767| 487002 RTD| 0| 14143| 501145 [[48]+/usr/xenomai/bin/cond-torture-native simple_condwait relative_condwait absolute_condwait sig_norestart_condwait sig_restart_condwait sig_norestart_condwait_mutex sig_restart_condwait_mutex sig_norestart_double sig_restart_double cond_destroy_whilewait Test OK [[49]+/usr/xenomai/bin/cond-torture-posix simple_condwait relative_condwait absolute_condwait sig_norestart_condwait sig_restart_condwait sig_norestart_condwait_mutex sig_restart_condwait_mutex sig_norestart_double sig_restart_double cond_destroy_whilewait Test OK [[50]+/usr/xenomai/bin/mutex-torture-native simple_wait recursive_wait timed_mutex mode_switch pi_wait lock_stealing NOTE: lock_stealing mutex_trylock: not supported deny_stealing simple_condwait recursive_condwait auto_switchback Test OK [[51]+/usr/xenomai/bin/mutex-torture-posix simple_wait recursive_wait errorcheck_wait timed_mutex mode_switch pi_wait lock_stealing NOTE: lock_stealing mutex_trylock: not supported deny_stealing simple_condwait recursive_condwait auto_switchback Test OK [[53]+start_load [[13]+echo start_load [[55]+check_alive /usr/xenomai/bin/latency [[8]+echo check_alive /usr/xenomai/bin/latency [[57]+wait_load [[18]+read rc Started child 3171: dohell 900 Started child 3172: /usr/xenomai/bin/latency == Sampling period: 1000 us == Test mode: periodic user-mode task == All results in microseconds warming up... RTT| 00:00:01 (periodic user-mode task, 1000 us period, priority 99) RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst RTD| 9.333| 15.999| 20.333| 0| 0| 9.333| 20.333 RTD| 9.333| 15.999| 20.999| 0| 0| 9.333| 20.999 RTD| 9.333| 16.333| 20.666| 0| 0| 9.333| 20.999 RTD| 8.999| 15.666| 21.333| 0| 0| 8.999| 21.333 RTD| 9.333| 15.999| 21.333| 0| 0| 8.999| 21.333 RTD| 9.333| 15.999| 21.333| 0| 0| 8.999| 21.333 RTD| 9.333| 15.999| 20.999| 0| 0| 8.999| 21.333 RTD| 9.333| 15.999| 20.999| 0| 0| 8.999| 21.333 RTD| 8.999| 16.333| 21.333| 0| 0| 8.999| 21.333 RTD| 8.999| 15.666| 20.999| 0| 0| 8.999| 21.333 RTD| 9.333| 15.999| 21.999| 0| 0| 8.999| 21.999 RTD| 8.999| 16.333| 20.999| 0| 0| 8.999| 21.999 RTD| 9.333| 16.333| 21.333| 0| 0| 8.999| 21.999 RTD| 9.666| 15.999| 20.999| 0| 0| 8.999| 21.999 RTD| 8.999| 15.666| 21.333| 0| 0| 8.999| 21.999 RTD| 9.333| 15.999| 20.666| 0| 0| 8.999| 21.999 RTD| 9.333| 15.999| 20.999| 0| 0| 8.999| 21.999 RTD| 9.333| 15.999| 21.333| 0| 0| 8.999| 21.999 RTD| 9.666| 15.999| 20.999| 0| 0| 8.999| 21.999 RTD| 9.666| 16.333| 20.999| 0| 0| 8.999| 21.999 RTD| 8.999| 15.666| 21.333| 0| 0| 8.999| 21.999 RTT| 00:00:22 (periodic user-mode task, 1000 us period, priority 99) RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst RTD| 9.333| 15.999| 20.999| 0| 0| 8.999| 21.999 RTD| 9.333| 16.333| 20.666| 0| 0| 8.999| 21.999 RTD| 9.333| 15.999| 21.333| 0| 0| 8.999| 21.999 RTD| 9.333| 15.999| 20.666| 0| 0| 8.999| 21.999 RTD| 8.999| 15.666| 21.333| 0| 0| 8.999| 21.999 RTD| 8.999| 15.999| 20.666| 0| 0| 8.999| 21.999 RTD| 9.333| 15.999| 20.666| 0| 0| 8.999| 21.999 RTD| 9.666| 15.999| 20.999| 0| 0| 8.999| 21.999 RTD| 9.666| 16.333| 21.333| 0| 0| 8.999| 21.999 RTD| 9.333| 15.999| 20.999| 0| 0| 8.999| 21.999 RTD| 8.999| 15.666| 20.999| 0| 0| 8.999| 21.999 RTD| 9.333| 16.333| 21.333| 0| 0| 8.999| 21.999 RTD| 9.333| 15.999| 21.333| 0| 0| 8.999| 21.999 RTD| 9.333| 16.333| 20.999| 0| 0| 8.999| 21.999 RTD| 9.333| 16.333| 21.666| 0| 0| 8.999| 21.999 ---|-----------|-----------|-----------|--------|------|------------------------- RTS| 8.999| 15.999| 21.999| 0| 0| 00:00:37/00:00:37 Il 03/10/2013 15:33, Drasko DRASKOVIC ha scritto: > On Thu, Oct 3, 2013 at 3:27 PM, Gilles Chanteperdrix > <gilles.chanteperdrix@xenomai.org> wrote: >> On 10/03/2013 10:36 AM, Roberto Bielli wrote: >>> Hi, >>> >>> i reduced drastically the latency disabling the cpu frequency scaling -> >>> CONFIG_CPU_FREQ ( max 25us ). >> This seems a bit too good to be true. Chances are higher to approach the >> real worst case latency on a system under load. > Can xeno-test give good and reliable figures for this case? > > BR, > Drasko -- +------------------------------------------------------------------------------------------------+ Roberto Bielli Sviluppo Software Axel S.r.l. Via Del Cannino, 3 21020 Crosio Della Valle Varese - Italy Telefono: +39 0332 949600 Fax: +39 0332 969315 E-mail: roberto.bielli@axelsw.it Web Site: www.axelsw.it +------------------------------------------------------------------------------------------------+ Si precisa che le informazioni contenute in questo messaggio sono riservate e ad uso esclusivo del destinatario. Qualora il messaggio in parola Le fosse pervenuto per errore, La preghiamo di eliminarlo senza copiarlo e di non inoltrarlo a terzi, dandocene gentilmente comunicazione. Grazie. Informativa sul trattamento dei dati personali (D. Lgs. 196/2003). I dati utilizzati per la spedizione del presente messaggio sono utilizzati da Axel S.r.l., titolare del trattamento, per l'invio delle comunicazioni dei diversi settori aziendali, non essendo autorizzata la divulgazione a terzi. Potrete rivolgere alla seguente mail richieste di verifica, rettifica o cancellazione dei Vostri dati: info@axelsw.it This e-mail and any attachments is confidential and may contain privileged information intended for the addressee(s) only. Dissemination, copying, printing or use by anybody else is unauthorised. If you are not the intended recipient, please delete this message and any attachments and advise the sender by return e-mail.Thank you. +------------------------------------------------------------------------------------------------+ ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Xenomai] high latency with imx6q without smp 2013-10-03 13:51 ` Roberto Bielli @ 2013-10-03 14:07 ` Gilles Chanteperdrix 0 siblings, 0 replies; 9+ messages in thread From: Gilles Chanteperdrix @ 2013-10-03 14:07 UTC (permalink / raw) To: Roberto Bielli; +Cc: xenomai@xenomai.org Roberto Bielli wrote: > Hi, > > the results of xeno-test are these. > When i execute the xeno-test i run simultaneously a telnet with an 'ls > -lr /' for increase etherne interrupts. To get reliable results, the system should run several hour, with load generated, for instance by running the dohell test. Si xeno-test --help and dohell --help. Even dohell without no argument is not a very good load. -- Gilles ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2013-10-03 14:07 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-10-01 12:24 [Xenomai] high latency with imx6q without smp Roberto Bielli 2013-10-01 12:26 ` Gilles Chanteperdrix 2013-10-01 12:50 ` Roberto Bielli 2013-10-01 19:10 ` Gilles Chanteperdrix 2013-10-03 8:36 ` Roberto Bielli 2013-10-03 13:27 ` Gilles Chanteperdrix 2013-10-03 13:33 ` Drasko DRASKOVIC 2013-10-03 13:51 ` Roberto Bielli 2013-10-03 14:07 ` Gilles Chanteperdrix
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