<div dir="ltr"> <div> </div><div>thumbs up from me, thanks for sending this.</div><div> </div><div>Auke</div><div> </div></div><div class="gmail_extra"> <div class="gmail_quote">On Thu, Jul 31, 2014 at 1:15 AM, Karel Zak <<a href="mailto:kzak@redhat.com" target="_blank">kzak@redhat.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">* systemd-bootchart always parses /proc/uptime, although the information is unnecessary when --rel specified * use /proc/uptime is overkill, since Linux 2.6.39 we have clock_gettime(CLOCK_BOOTTIME, ...). The backend on kernel side is get_monotonic_boottime() in both cases. * main() uses "if (graph_start <= 0.0)" to detect that /proc is available. This is fragile solution as graph_start is always smaller than zero on all systems after suspend/resume (e.g. laptops), because in this case the system uptime includes suspend time and uptime is always greater number than monotonic time. For example right now difference between uptime and monotonic time is 37 hours on my laptop. Note that main() calls log_uptime() (to parse /proc/uptime) for each sample when it believes that /proc is not available. So on my laptop systemd-boochars spends all live with /proc/uptime parsing + nanosleep(), try strace /usr/lib/systemd/systemd-bootchart to see the never ending loop. This patch uses access("/proc/vmstat", F_OK) to detect procfs. --- man/systemd-bootchart.xml | 4 +++- src/bootchart/bootchart.c | 11 +++++++---- src/bootchart/store.c | 29 ++++++++++++----------------- 3 files changed, 22 insertions(+), 22 deletions(-) diff --git a/man/systemd-bootchart.xml b/man/systemd-bootchart.xml index e19bbc1..150ca48 100644 --- a/man/systemd-bootchart.xml +++ b/man/systemd-bootchart.xml @@ -131,7 +131,9 @@ not graph the time elapsed since boot and before systemd-bootchart was started, as it may result in extremely - large graphs. </para></listitem> + large graphs. The time elapsed since boot + might also include any time that the system + was suspended.</para></listitem> </varlistentry> </variablelist> </refsect1> diff --git a/src/bootchart/bootchart.c b/src/bootchart/bootchart.c index cbfc28d..909ef46 100644 --- a/src/bootchart/bootchart.c +++ b/src/bootchart/bootchart.c @@ -310,6 +310,7 @@ int main(int argc, char *argv[]) { time_t t = 0; int r; struct rlimit rlim; + bool has_procfs = false; parse_conf(); @@ -349,6 +350,8 @@ int main(int argc, char *argv[]) { log_uptime(); + has_procfs = access("/proc/vmstat", F_OK) == 0; + LIST_HEAD_INIT(head); /* main program loop */ @@ -385,11 +388,11 @@ int main(int argc, char *argv[]) { parse_env_file("/usr/lib/os-release", NEWLINE, "PRETTY_NAME", &build, NULL); } - /* wait for /proc to become available, discarding samples */ - if (graph_start <= 0.0) - log_uptime(); - else + if (has_procfs) log_sample(samples, &sampledata); + else + /* wait for /proc to become available, discarding samples */ + has_procfs = access("/proc/vmstat", F_OK) == 0; sample_stop = gettime_ns(); diff --git a/src/bootchart/store.c b/src/bootchart/store.c index e071983..cedcba8 100644 --- a/src/bootchart/store.c +++ b/src/bootchart/store.c @@ -57,27 +57,22 @@ double gettime_ns(void) { return (n.tv_sec + (n.tv_nsec / 1000000000.0)); } -void log_uptime(void) { - _cleanup_fclose_ FILE *f = NULL; - char str[32]; - double uptime; - - f = fopen("/proc/uptime", "re"); - - if (!f) - return; - if (!fscanf(f, "%s %*s", str)) - return; - - uptime = strtod(str, NULL); +static double gettime_up(void) { + struct timespec n; - log_start = gettime_ns(); + clock_gettime(CLOCK_BOOTTIME, &n); + return (n.tv_sec + (n.tv_nsec / 1000000000.0)); +} - /* start graph at kernel boot time */ +void log_uptime(void) { if (arg_relative) - graph_start = log_start; - else + graph_start = log_start = gettime_ns(); + else { + double uptime = gettime_up(); + + log_start = gettime_ns(); graph_start = log_start - uptime; + } } static char *bufgetline(char *buf) { -- 1.9.3 _______________________________________________ systemd-devel mailing list <a href="mailto:systemd-devel@lists.freedesktop.org">systemd-devel@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/systemd-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/systemd-devel</a> </blockquote></div> </div>