Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755334AbcK1UL4 (ORCPT ); Mon, 28 Nov 2016 15:11:56 -0500 Received: from p3plsmtps2ded02.prod.phx3.secureserver.net ([208.109.80.59]:52464 "EHLO p3plsmtps2ded02.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754856AbcK1T4m (ORCPT ); Mon, 28 Nov 2016 14:56:42 -0500 x-originating-ip: 72.167.245.219 From: Matthew Wilcox To: linux-kernel@vger.kernel.org, Andrew Morton , Konstantin Khlebnikov , Ross Zwisler Cc: Matthew Wilcox , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, "Kirill A . Shutemov" Subject: [PATCH v3 06/33] radix tree test suite: Make runs more reproducible Date: Mon, 28 Nov 2016 13:50:10 -0800 Message-Id: <1480369871-5271-7-git-send-email-mawilcox@linuxonhyperv.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1480369871-5271-1-git-send-email-mawilcox@linuxonhyperv.com> References: <1480369871-5271-1-git-send-email-mawilcox@linuxonhyperv.com> X-CMAE-Envelope: MS4wfEPIPgdpaMk+7QtiVYs958MhPLzdk5g5DBPz5ldnhDJLByU08okGG1+6880unHSUoeP2iocuDGM+V9od1Jlkr+SdUuaGwd6G4fPpmSTLYNo9cXmLR5rM UQSXRcojYWpDfJ7YmgwSKEw0xEuCo5mx/Qylmj2MeOlmCicaucerDOWuiL2Cit+i2t0F7fpAyIP+p/QfEOrgQST91GlJvL5RYwMGp8MVhhC26y2puaUJpuSk 7DVTM0mhh0iU/YOHg0Bm2M13cB6CoM9bv4HUuU41GG2EpRLZwHAGl/UoZgKmjf/lJbaUe1ylQk/tjl96ZPiEpeMp6RHX4DiDlltAbSg3mnndAmBZOF9CziYp aZSM107KHKgPcnXAciML4YcncbWX6ePLDE7tXYqRd8wFscQ70LnkPGoVTmBRU5CWcn0n3s7QUmTN1duDnkHzOZn1PU8j9pbtIUc+X/QHD8fI8Gpwfbs= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3076 Lines: 105 From: Matthew Wilcox Instead of reseeding the random number generator every time around the loop in big_gang_check(), seed it at the beginning of execution. Use rand_r() and an independent base seed for each thread in iteration_test() so they don't stomp all over each others state. Since this particular test depends on the kernel scheduler, the iteration test can't be reproduced based purely on the random seed, but at least it won't pollute the other tests. Print the seed, and allow the seed to be specified so that a run which hits a problem can be reproduced. Signed-off-by: Matthew Wilcox --- tools/testing/radix-tree/iteration_check.c | 11 +++++++---- tools/testing/radix-tree/main.c | 9 +++++++-- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/tools/testing/radix-tree/iteration_check.c b/tools/testing/radix-tree/iteration_check.c index 9adb8e7..11d570c 100644 --- a/tools/testing/radix-tree/iteration_check.c +++ b/tools/testing/radix-tree/iteration_check.c @@ -20,6 +20,7 @@ #define TAG 0 static pthread_mutex_t tree_lock = PTHREAD_MUTEX_INITIALIZER; static pthread_t threads[NUM_THREADS]; +static unsigned int seeds[3]; RADIX_TREE(tree, GFP_KERNEL); bool test_complete; @@ -71,7 +72,7 @@ static void *tagged_iteration_fn(void *arg) continue; } - if (rand() % 50 == 0) + if (rand_r(&seeds[0]) % 50 == 0) slot = radix_tree_iter_next(&iter); } rcu_read_unlock(); @@ -111,7 +112,7 @@ static void *untagged_iteration_fn(void *arg) continue; } - if (rand() % 50 == 0) + if (rand_r(&seeds[1]) % 50 == 0) slot = radix_tree_iter_next(&iter); } rcu_read_unlock(); @@ -129,7 +130,7 @@ static void *remove_entries_fn(void *arg) while (!test_complete) { int pgoff; - pgoff = rand() % 100; + pgoff = rand_r(&seeds[2]) % 100; pthread_mutex_lock(&tree_lock); item_delete(&tree, pgoff); @@ -146,9 +147,11 @@ void iteration_test(void) printf("Running iteration tests for 10 seconds\n"); - srand(time(0)); test_complete = false; + for (i = 0; i < 3; i++) + seeds[i] = rand(); + if (pthread_create(&threads[0], NULL, tagged_iteration_fn, NULL)) { perror("pthread_create"); exit(1); diff --git a/tools/testing/radix-tree/main.c b/tools/testing/radix-tree/main.c index 52ce1ea..2eb6949 100644 --- a/tools/testing/radix-tree/main.c +++ b/tools/testing/radix-tree/main.c @@ -67,7 +67,6 @@ void big_gang_check(bool long_run) for (i = 0; i < (long_run ? 1000 : 3); i++) { __big_gang_check(); - srand(time(0)); printf("%d ", i); fflush(stdout); } @@ -329,12 +328,18 @@ int main(int argc, char **argv) { bool long_run = false; int opt; + unsigned int seed = time(NULL); - while ((opt = getopt(argc, argv, "l")) != -1) { + while ((opt = getopt(argc, argv, "ls:")) != -1) { if (opt == 'l') long_run = true; + else if (opt == 's') + seed = strtoul(optarg, NULL, 0); } + printf("random seed %u\n", seed); + srand(seed); + rcu_register_thread(); radix_tree_init(); -- 2.10.2