From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank Rowand Subject: Re: [PATCH] cyclictest histogram overflow instance tracking Date: Mon, 15 Oct 2012 11:11:01 -0700 Message-ID: <507C51B5.2060505@am.sony.com> References: <21A665E0-66F4-4C7E-BDB2-820DDC5398C8@vmware.com> <507724B2.5050103@am.sony.com> <9C1EE6A5-2B57-45AC-B4D7-5AF7F56A7BCA@vmware.com> <6B64752A-B20A-4C14-A402-5859EF84D02B@vmware.com> Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Rowand, Frank" , "linux-rt-users@vger.kernel.org" , Garrett Smith , Lenin Singaravelu To: Bhavesh Davda , , Return-path: Received: from va3ehsobe003.messaging.microsoft.com ([216.32.180.13]:15292 "EHLO va3outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752121Ab2JOSLO convert rfc822-to-8bit (ORCPT ); Mon, 15 Oct 2012 14:11:14 -0400 In-Reply-To: <6B64752A-B20A-4C14-A402-5859EF84D02B@vmware.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 10/15/12 09:38, Bhavesh Davda wrote: > Hello Frank, >=20 > Friendly ping, to make sure this doesn't fall through the cracks. You need to ping Clark Williams or John Kacur (not sure which...). >=20 > Thanks >=20 > - Bhavesh >=20 > On Oct 11, 2012, at 1:59 PM, Bhavesh Davda wrote: >=20 >> Thanks for the review, Frank. >> >> On Oct 11, 2012, at 12:57 PM, Frank Rowand wrote: >>> Nice idea=85 >> Thanks >> >>> Suggest: >>> printf("# Histogram Overflows at cycle number:"); >>> >> Done >> >>>> - printf(" %05lu", par[j]->stats->hist_overflow); >>>> + printf(" %05lu", par[j]->stats->hist_overflow); >>> >>> Am I blind, or is that a whitespace change? (The latest version I = have does not seem >>> to have any white space issues in that line.) >>> >> Turns out I had removed extraneous whitespace. My vim settings allow= me to see extraneous whitespaces in red, so I get annoyed by them and = can fix them up. So I've removed a few more in the revised diffs (sorry= !) >> >>> Suggest: >>> >>> + printf("# thread %d:", j); >>> >> Done >> >>> Nit: You don't need stats->outliers_overflow. You can calculate it= from >>> stats->hist_overflow - stats->num_outliers: >>> >> Nice catch! I've removed outliers_overflow now. >> >> >> From: Bhavesh Davda >> >> Add feature to cyclictest histogram mode to track cycle counts every= time a >> sample overflows the histogram limit. This should help identify if t= here is a >> timing pattern to jitters in cyclictest runs. >> >> Example output (with -h 10): >> ... >> Histogram Overflows: 00000 00253 00000 00005 00000 00024 00003 0000= 5 >> Histogram Overflow at cycle number: >> Thread 0: >> Thread 1: 00023 00028 00337 00338 00339 00340 00341 00342 00343 003= 44 # 00243 others >> Thread 2: >> Thread 3: 10486 10487 10488 10489 10490 >> Thread 4: >> Thread 5: 00002 00004 00008 00012 00178 10458 10459 10460 10461 104= 62 # 00014 others >> Thread 6: 05954 08954 29955 >> Thread 7: 20536 20537 20538 20539 20540 >> ... >> >> Signed-off-by: Bhavesh Davda >> --- >> src/cyclictest/cyclictest.c | 38 +++++++++++++++++++++++++++++----= ----- >> 1 files changed, 29 insertions(+), 9 deletions(-) >> >> diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest= =2Ec >> index 731b4bd..dc985de 100644 >> --- a/src/cyclictest/cyclictest.c >> +++ b/src/cyclictest/cyclictest.c >> @@ -147,6 +147,7 @@ struct thread_stat { >> double avg; >> long *values; >> long *hist_array; >> + unsigned long *outliers; >> pthread_t thread; >> int threadstarted; >> int tid; >> @@ -154,6 +155,7 @@ struct thread_stat { >> long redmax; >> long cycleofmax; >> long hist_overflow; >> + long num_outliers; >> }; >> >> static int shutdown; >> @@ -756,8 +758,11 @@ void *timerthread(void *param) >> >> /* Update the histogram */ >> if (histogram) { >> - if (diff >=3D histogram) >> + if (diff >=3D histogram) { >> stat->hist_overflow++; >> + if (stat->num_outliers < histogram) >> + stat->outliers[stat->num_outliers++] =3D stat->cycles - 1; >> + } >> else >> stat->hist_array[diff]++; >> } >> @@ -811,7 +816,7 @@ static void display_help(int error) >> if (kernvar(O_RDONLY, "available_tracers", tracers, sizeof(tracers= ))) >> strcpy(tracers, "none"); >> } >> - =09 >> + >> printf("cyclictest V %1.2f\n", VERSION_STRING); >> printf("Usage:\n" >> "cyclictest \n\n" >> @@ -1188,7 +1193,7 @@ static int check_kernel(void) >> kv =3D KV_30; >> strcpy(functiontracer, "function"); >> strcpy(traceroptions, "trace_options"); >> - =09 >> + >> } else >> kv =3D KV_NOT_SUPPORTED; >> >> @@ -1226,7 +1231,7 @@ static void print_tids(struct thread_param *pa= r[], int nthreads) >> >> static void print_hist(struct thread_param *par[], int nthreads) >> { >> - int i, j; >> + int i, j, k; >> unsigned long long int log_entries[nthreads+1]; >> unsigned long maxmax, alloverflows; >> >> @@ -1270,7 +1275,7 @@ static void print_hist(struct thread_param *pa= r[], int nthreads) >> printf("# Max Latencies:"); >> maxmax =3D 0; >> for (j =3D 0; j < nthreads; j++) { >> - printf(" %05lu", par[j]->stats->max); >> + printf(" %05lu", par[j]->stats->max); >> if (par[j]->stats->max > maxmax) >> maxmax =3D par[j]->stats->max; >> } >> @@ -1280,9 +1285,20 @@ static void print_hist(struct thread_param *p= ar[], int nthreads) >> printf("# Histogram Overflows:"); >> alloverflows =3D 0; >> for (j =3D 0; j < nthreads; j++) { >> - printf(" %05lu", par[j]->stats->hist_overflow); >> + printf(" %05lu", par[j]->stats->hist_overflow); >> alloverflows +=3D par[j]->stats->hist_overflow; >> } >> + printf("\n"); >> + printf("# Histogram Overflow at cycle number:\n"); >> + for (j =3D 0; j < nthreads; j++) { >> + printf("# Thread %d:", j); >> + for (k =3D 0; k < par[j]->stats->num_outliers; k++) >> + printf(" %05lu", par[j]->stats->outliers[k]); >> + if (par[j]->stats->num_outliers < par[j]->stats->hist_overflow) >> + printf(" # %05lu others", par[j]->stats->hist_overflow - par[j]-= >stats->num_outliers); >> + printf("\n"); >> + } >> + >> if (histofall && nthreads > 1) >> printf(" %05lu", alloverflows); >> printf("\n"); >> @@ -1434,10 +1450,12 @@ int main(int argc, char **argv) >> int bufsize =3D histogram * sizeof(long); >> >> stat->hist_array =3D threadalloc(bufsize, node); >> - if (stat->hist_array =3D=3D NULL) >> + stat->outliers =3D threadalloc(bufsize, node); >> + if (stat->hist_array =3D=3D NULL || stat->outliers =3D=3D NULL) >> fatal("failed to allocate histogram of size %d on node %d\n", >> histogram, i); >> memset(stat->hist_array, 0, bufsize); >> + memset(stat->outliers, 0, bufsize); >> } >> >> if (verbose) { >> @@ -1553,8 +1571,10 @@ int main(int argc, char **argv) >> >> if (histogram) { >> print_hist(parameters, num_threads); >> - for (i =3D 0; i < num_threads; i++) >> + for (i =3D 0; i < num_threads; i++) { >> threadfree(statistics[i]->hist_array, histogram*sizeof(long), par= ameters[i]->node); >> + threadfree(statistics[i]->outliers, histogram*sizeof(long), para= meters[i]->node); >> + } >> } >> >> if (tracelimit) { >> @@ -1564,7 +1584,7 @@ int main(int argc, char **argv) >> printf("# Break value: %lu\n", break_thread_value); >> } >> } >> -=09 >> + >> >> for (i=3D0; i < num_threads; i++) { >> if (!statistics[i]) >> --=20 >> 1.7.1 >> >=20 > -- > Bhavesh Davda > bhavesh@vmware.com -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html