From d3b7767a64af0cd57d17b888e4ec3bdae6fdab87 Mon Sep 17 00:00:00 2001 From: xie xingguo Date: Sat, 14 May 2016 11:28:04 +0800 Subject: [PATCH] osd: fix sched_time not actually randomized The test program: main() { for (int i = 0; i < 1000; i++) { double before = rand() / RAND_MAX; double after = rand() / (double)RAND_MAX; cout << "before: " << before << " after: " << after << endl; } } And the output(partial and with "-std=c++11" option): before: 0 after: 0.394383 before: 0 after: 0.79844 before: 0 after: 0.197551 before: 0 after: 0.76823 before: 0 after: 0.55397 before: 0 after: 0.628871 before: 0 after: 0.513401 before: 0 after: 0.916195 before: 0 after: 0.717297 before: 0 after: 0.606969 before: 0 after: 0.242887 before: 0 after: 0.804177 before: 0 after: 0.400944 before: 0 after: 0.108809 before: 0 after: 0.218257 before: 0 after: 0.839112 before: 0 after: 0.296032 before: 0 after: 0.524287 Fixes: http://tracker.ceph.com/issues/15890 Signed-off-by: xie xingguo --- src/osd/OSD.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc index 0bfb0eab4c61..126488f04936 100644 --- a/src/osd/OSD.cc +++ b/src/osd/OSD.cc @@ -6429,7 +6429,7 @@ OSDService::ScrubJob::ScrubJob(const spg_t& pg, const utime_t& timestamp, pool_scrub_max_interval : g_conf->osd_scrub_max_interval; sched_time += scrub_min_interval; - double r = rand() / RAND_MAX; + double r = rand() / (double)RAND_MAX; sched_time += scrub_min_interval * g_conf->osd_scrub_interval_randomize_ratio * r; deadline += scrub_max_interval; -- 2.47.3