From 9224515cd6b19ba2dc59afe14684749b4dbf0349 Mon Sep 17 00:00:00 2001 From: Daniel van Vugt Date: Fri, 27 Oct 2017 19:11:33 +0800 Subject: [PATCH] Fix inaccurate %CPU values in the Processes table MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Multi-core machines were displaying inaccurate %CPU values due to a loss of precision from performing integer division before multiplication. This changes the order of operations so that no precision is lost, and now all machines will display process %CPU values to within 1% accuracy. https://bugzilla.gnome.org/show_bug.cgi?id=788922 Signed-off-by: Benoît Dejean --- src/proctable.cpp | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/src/proctable.cpp b/src/proctable.cpp index e41d6d08..c37a48b2 100644 --- a/src/proctable.cpp +++ b/src/proctable.cpp @@ -917,11 +917,13 @@ update_info (GsmApplication *app, ProcInfo *info) guint64 difference = proctime.rtime - info->cpu_time; if (difference > 0) info->status = GLIBTOP_PROCESS_RUNNING; - info->pcpu = difference * 100 / app->cpu_total_time; - info->pcpu = MIN(info->pcpu, 100); + guint cpu_scale = 100; if (not app->config.solaris_mode) - info->pcpu *= app->config.num_cpus; + cpu_scale *= app->config.num_cpus; + + info->pcpu = difference * cpu_scale / app->cpu_total_time; + info->pcpu = MIN(info->pcpu, cpu_scale); app->processes.cpu_times[info->pid] = info->cpu_time = proctime.rtime; info->nice = procuid.nice; -- 2.15.0