From patchwork Tue Mar 31 11:34:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Lucas A. M. Magalhaes" X-Patchwork-Id: 38687 Return-Path: X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by sourceware.org (Postfix) with ESMTPS id EDE90385B835 for ; Tue, 31 Mar 2020 11:34:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org EDE90385B835 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 02VBXpCY146998 for ; Tue, 31 Mar 2020 07:34:42 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3020wdkvpt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 31 Mar 2020 07:34:41 -0400 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 02VBYFGZ001675 for ; Tue, 31 Mar 2020 07:34:41 -0400 Received: from ppma03wdc.us.ibm.com (ba.79.3fa9.ip4.static.sl-reverse.com [169.63.121.186]) by mx0a-001b2d01.pphosted.com with ESMTP id 3020wdkvp9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 31 Mar 2020 07:34:41 -0400 Received: from pps.filterd (ppma03wdc.us.ibm.com [127.0.0.1]) by ppma03wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id 02VBUaXY029116; Tue, 31 Mar 2020 11:34:40 GMT Received: from b01cxnp22036.gho.pok.ibm.com (b01cxnp22036.gho.pok.ibm.com [9.57.198.26]) by ppma03wdc.us.ibm.com with ESMTP id 301x76gfw2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 31 Mar 2020 11:34:40 +0000 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 02VBYdNi13632106 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 31 Mar 2020 11:34:39 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AD52FAC059; Tue, 31 Mar 2020 11:34:39 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 54658AC05E; Tue, 31 Mar 2020 11:34:39 +0000 (GMT) Received: from localhost (unknown [9.85.140.203]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 31 Mar 2020 11:34:39 +0000 (GMT) From: "Lucas A. M. Magalhaes" To: libc-alpha@sourceware.org Subject: [PATCH v6] Fix time/tst-cpuclock1 intermitent failures Date: Tue, 31 Mar 2020 08:34:38 -0300 Message-Id: <20200331113438.10103-1-lamm@linux.ibm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200323172008.11370-1-lamm@linux.ibm.com> References: <20200323172008.11370-1-lamm@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.676 definitions=2020-03-31_04:2020-03-31, 2020-03-31 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 impostorscore=0 priorityscore=1501 malwarescore=0 phishscore=0 mlxlogscore=999 adultscore=0 suspectscore=0 bulkscore=0 mlxscore=0 lowpriorityscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2003310101 X-Spam-Status: No, score=-25.7 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_DMARC_STATUS, KAM_SHORT, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Mar 2020 11:34:45 -0000 This test fails intermittently in systems with heavy load as CLOCK_PROCESS_CPUTIME_ID is subject to scheduler pressure. Thus the test boundaries were relaxed to keep it from failing on such systems. A refactor of the spent time checking was made with some support functions. With the advantage to representing time jitter in percent of the target. The values used by the test boundaries are all empirical. --- Hi, changes on V6: - add overflow handling - change variables names changes on V5: - add tests for support_timespec_check_in_range - fix support_timespec_normalize - add comments - fix style changes on V4: - move functions to support/timespec.c - simplify functions changes on V3: - refactor support functions - use existing timespec-sub function changes on V2: - Add support functions --- support/Makefile | 1 + support/timespec.c | 54 +++++++++++++++ support/timespec.h | 6 ++ support/tst-timespec.c | 147 +++++++++++++++++++++++++++++++++++++++++ time/tst-cpuclock1.c | 48 +++++--------- 5 files changed, 226 insertions(+), 30 deletions(-) create mode 100644 support/tst-timespec.c diff --git a/support/Makefile b/support/Makefile index 6e38b87ebe..cacaac96a5 100644 --- a/support/Makefile +++ b/support/Makefile @@ -233,6 +233,7 @@ tests = \ tst-test_compare \ tst-test_compare_blob \ tst-test_compare_string \ + tst-timespec \ tst-xreadlink \ tst-xsigstack \ diff --git a/support/timespec.c b/support/timespec.c index ea6b947546..0f840c2764 100644 --- a/support/timespec.c +++ b/support/timespec.c @@ -19,6 +19,8 @@ #include #include #include +#include +#include void test_timespec_before_impl (const char *file, int line, @@ -57,3 +59,55 @@ test_timespec_equal_or_after_impl (const char *file, int line, (intmax_t) diff.tv_sec, (intmax_t) diff.tv_nsec); } } + +/* Returns t normalized timespec with .tv_nsec < TIMESPEC_HZ + and the overflows added to .tv_sec. It assumes times are + positive. */ +struct timespec +support_timespec_normalize (struct timespec time) +{ + struct timespec norm; + if (INT_ADD_WRAPV (time.tv_sec, (time.tv_nsec / TIMESPEC_HZ), &norm.tv_sec)) + { + norm.tv_sec = (time.tv_nsec < 0) ? TYPE_MINIMUM (time_t):TYPE_MAXIMUM (time_t); + } + norm.tv_nsec = time.tv_nsec % TIMESPEC_HZ; + return norm; +} + +#define TIMESPEC_SHRINK(time, shrinked) \ +{ \ + if (INT_MULTIPLY_WRAPV(time.tv_sec, TIMESPEC_HZ, &shrinked)) \ + { \ + shrinked = (time.tv_sec < 0) ? TYPE_MINIMUM(long): TYPE_MAXIMUM(long); \ + } \ + if (INT_ADD_WRAPV(shrinked, time.tv_nsec, &shrinked)) \ + { \ + shrinked = (time.tv_nsec < 0) ? TYPE_MINIMUM(long): TYPE_MAXIMUM(long); \ + } \ +} \ + +/* Returns TRUE if the observed time is within the given percentage bounds of +the expected time, and FALSE otherwise. +For example the call + +support_timespec_check_in_range(expected, observed, .5, 1.2); + +will check if + +.5 <= observed/expected <= 1.2 + +In other words it will check if observed time is within 50% to 120% of +the expected time. */ +int +support_timespec_check_in_range (struct timespec expected, struct timespec observed, + double lower_bound, double upper_bound) +{ + assert (upper_bound >= lower_bound); + long expected_norm, observed_norm; + TIMESPEC_SHRINK(expected, expected_norm); + assert(expected_norm != 0); + TIMESPEC_SHRINK(observed, observed_norm); + double ratio = (double)observed_norm / expected_norm; + return (lower_bound <= ratio && ratio <= upper_bound); +} diff --git a/support/timespec.h b/support/timespec.h index c5852dfe75..86040627c2 100644 --- a/support/timespec.h +++ b/support/timespec.h @@ -48,6 +48,12 @@ void test_timespec_equal_or_after_impl (const char *file, int line, const struct timespec left, const struct timespec right); +struct timespec support_timespec_normalize (struct timespec time); + +int support_timespec_check_in_range (struct timespec expected, struct timespec observed, + double lower_bound, double upper_bound); + + /* Check that the timespec on the left represents a time before the time on the right. */ #define TEST_TIMESPEC_BEFORE(left, right) \ diff --git a/support/tst-timespec.c b/support/tst-timespec.c new file mode 100644 index 0000000000..06d817a421 --- /dev/null +++ b/support/tst-timespec.c @@ -0,0 +1,147 @@ +/* Test for support_timespec_check_in_range function. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include + +struct timespec_test_case +{ + struct timespec expected; + struct timespec observed; + double upper_bound; + double lower_bound; + int result; +}; + +struct timespec_test_case test_cases[] = { + // 0 - In range + {.expected = { .tv_sec = 1, .tv_nsec = 0}, + .observed = {.tv_sec = 1, .tv_nsec = 0}, + .upper_bound = 1, .lower_bound = 1, .result = 1, + }, + // 1 - Out of range + {.expected = { .tv_sec = 1, .tv_nsec = 0}, + .observed = {.tv_sec = 2, .tv_nsec = 0}, + .upper_bound = 1, .lower_bound = 1, .result = 0, + }, + // 2 - Upper Bound + {.expected = { .tv_sec = 1, .tv_nsec = 0}, + .observed = {.tv_sec = 2, .tv_nsec = 0}, + .upper_bound = 2, .lower_bound = 1, .result = 1, + }, + // 3 - Lower Bound + {.expected = { .tv_sec = 1, .tv_nsec = 0}, + .observed = {.tv_sec = 0, .tv_nsec = 0}, + .upper_bound = 1, .lower_bound = 0, .result = 1, + }, + // 4 - Out of range by nanosecs + {.expected = { .tv_sec = 1, .tv_nsec = 0}, + .observed = {.tv_sec = 1, .tv_nsec = 500}, + .upper_bound = 1, .lower_bound = 1, .result = 0, + }, + // 5 - In range by nanosecs + {.expected = { .tv_sec = 1, .tv_nsec = 0}, + .observed = {.tv_sec = 1, .tv_nsec = 50000}, + .upper_bound = 1.3, .lower_bound = 1, .result = 1, + }, + // 6 - Big nanosecs + {.expected = { .tv_sec = 1, .tv_nsec = 0}, + .observed = {.tv_sec = 0, .tv_nsec = 4000000}, + .upper_bound = 1, .lower_bound = .001, .result = 1, + }, + // 7 - In range Negative values + {.expected = { .tv_sec = -1, .tv_nsec = 0}, + .observed = {.tv_sec = -1, .tv_nsec = 0}, + .upper_bound = 1, .lower_bound = 1, .result = 1, + }, + // 8 - Out of range Negative values + {.expected = { .tv_sec = -1, .tv_nsec = 0}, + .observed = {.tv_sec = -1, .tv_nsec = 0}, + .upper_bound = -1, .lower_bound = -1, .result = 0, + }, + // 9 - Negative values with negative nanosecs + {.expected = { .tv_sec = -1, .tv_nsec = 0}, + .observed = {.tv_sec = -1, .tv_nsec = -2000}, + .upper_bound = 1, .lower_bound = 1, .result = 0, + }, + // 10 - Strict bounds + {.expected = { .tv_sec = -1, .tv_nsec = 0}, + .observed = {.tv_sec = -1, .tv_nsec = -20000}, + .upper_bound = 1.00002, .lower_bound = 1.0000191, .result = 1, + }, + // 11 - Strict bounds with loose upper bound + {.expected = { .tv_sec = 1, .tv_nsec = 20000}, + .observed = {.tv_sec = 1, .tv_nsec = 30000}, + .upper_bound = 1.0000100000, .lower_bound = 1.0000099998, .result = 1, + }, + // 12 - Strict bounds with loose lower bound + {.expected = { .tv_sec = 1, .tv_nsec = 20000}, + .observed = {.tv_sec = 1, .tv_nsec = 30000}, + .upper_bound = 1.0000099999, .lower_bound = 1.00000999979, .result = 1, + }, + // 13 - Strict bounds highest precision + {.expected = { .tv_sec = 1, .tv_nsec = 20000}, + .observed = {.tv_sec = 1, .tv_nsec = 30000}, + .upper_bound = 1.00000999980001, .lower_bound = 1.00000999979999, .result = 1, + }, + /* Maximum/Minimum long values */ + // 14 + {.expected = { .tv_sec = LONG_MAX, .tv_nsec = LONG_MAX}, + .observed = {.tv_sec = LONG_MAX, .tv_nsec = LONG_MAX -1}, + .upper_bound = 1, .lower_bound = .9, .result = 1, + }, + // 15 + {.expected = { .tv_sec = LONG_MAX, .tv_nsec = LONG_MAX}, + .observed = {.tv_sec = LONG_MAX, .tv_nsec = LONG_MAX}, + .upper_bound = 1, .lower_bound = 1, .result = 1, + }, + // 16 + {.expected = { .tv_sec = LONG_MAX, .tv_nsec = LONG_MAX}, + .observed = {.tv_sec = LONG_MIN, .tv_nsec = LONG_MIN}, + .upper_bound = 1, .lower_bound = 1, .result = 0, + }, + // 17 + {.expected = { .tv_sec = LONG_MIN, .tv_nsec = LONG_MIN}, + .observed = {.tv_sec = LONG_MIN, .tv_nsec = LONG_MIN}, + .upper_bound = 1, .lower_bound = 1, .result = 1, + }, + // 18 + {.expected = { .tv_sec = LONG_MIN, .tv_nsec = LONG_MIN}, + .observed = {.tv_sec = LONG_MAX, .tv_nsec = LONG_MAX}, + .upper_bound = 1, .lower_bound = 1, .result = 0, + } +}; + +static int +do_test (void) +{ + int i = 0; + + int ntests = sizeof (test_cases) / sizeof (test_cases); + for (i = 0; i < ntests; i++) + { + TEST_COMPARE (support_timespec_check_in_range + (test_cases[i].expected, test_cases[i].observed, + test_cases[i].lower_bound, + test_cases[i].upper_bound), test_cases[i].result); + } + return 0; +} + +#include diff --git a/time/tst-cpuclock1.c b/time/tst-cpuclock1.c index 0120906f23..fe9bb0a31e 100644 --- a/time/tst-cpuclock1.c +++ b/time/tst-cpuclock1.c @@ -26,6 +26,7 @@ #include #include #include +#include /* This function is intended to rack up both user and system time. */ static void @@ -155,16 +156,11 @@ do_test (void) printf ("live PID %d after sleep => %ju.%.9ju\n", child, (uintmax_t) after.tv_sec, (uintmax_t) after.tv_nsec); - struct timespec diff = { .tv_sec = after.tv_sec - before.tv_sec, - .tv_nsec = after.tv_nsec - before.tv_nsec }; - if (diff.tv_nsec < 0) - { - --diff.tv_sec; - diff.tv_nsec += 1000000000; - } - if (diff.tv_sec != 0 - || diff.tv_nsec > 600000000 - || diff.tv_nsec < 100000000) + /* The bound values are empirically defined by testing this code over high cpu + usage and different nice values. */ + struct timespec diff = timespec_sub (support_timespec_normalize (after), + support_timespec_normalize (before)); + if (!support_timespec_check_in_range (sleeptime, diff, .0025, 1.3)) { printf ("before - after %ju.%.9ju outside reasonable range\n", (uintmax_t) diff.tv_sec, (uintmax_t) diff.tv_nsec); @@ -194,19 +190,14 @@ do_test (void) } else { - struct timespec d = { .tv_sec = afterns.tv_sec - after.tv_sec, - .tv_nsec = afterns.tv_nsec - after.tv_nsec }; - if (d.tv_nsec < 0) - { - --d.tv_sec; - d.tv_nsec += 1000000000; - } - if (d.tv_sec > 0 - || d.tv_nsec < sleeptime.tv_nsec - || d.tv_nsec > sleeptime.tv_nsec * 2) + /* The bound values are empirically defined by testing this code over + high cpu usage and different nice values. */ + diff = timespec_sub (support_timespec_normalize (afterns), + support_timespec_normalize (after)); + if (!support_timespec_check_in_range (sleeptime, diff, .71, 1.6)) { printf ("nanosleep time %ju.%.9ju outside reasonable range\n", - (uintmax_t) d.tv_sec, (uintmax_t) d.tv_nsec); + (uintmax_t) diff.tv_sec, (uintmax_t) diff.tv_nsec); result = 1; } } @@ -240,15 +231,12 @@ do_test (void) /* Should be close to 0.6. */ printf ("dead PID %d => %ju.%.9ju\n", child, (uintmax_t) dead.tv_sec, (uintmax_t) dead.tv_nsec); - - diff.tv_sec = dead.tv_sec - after.tv_sec; - diff.tv_nsec = dead.tv_nsec - after.tv_nsec; - if (diff.tv_nsec < 0) - { - --diff.tv_sec; - diff.tv_nsec += 1000000000; - } - if (diff.tv_sec != 0 || diff.tv_nsec > 200000000) + /* The bound values are empirically defined by testing this code over high cpu + usage and different nice values. */ + diff = timespec_sub (support_timespec_normalize (dead), + support_timespec_normalize (after)); + sleeptime.tv_nsec = 100000000; + if (!support_timespec_check_in_range (sleeptime, diff, .7, 1.6)) { printf ("dead - after %ju.%.9ju outside reasonable range\n", (uintmax_t) diff.tv_sec, (uintmax_t) diff.tv_nsec);