jolly has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmocore/+/35672?usp=email )
Change subject: Prevent poll() in select.c to timeout too early ......................................................................
Prevent poll() in select.c to timeout too early
Adjust osmo_timers_nearest_ms() to round up the remaining time.
Note that poll() has a granularity of 1 millisecond.
Previously, when rounding down the remaining time, osmo_select_main() would return too early, before the nearest timer timed out. Consequently, the main loop repeatedly called osmo_select_main() until the timer actually timed out, resulting in excessive CPU usage. By modifying osmo_timers_nearest_ms() to round up the remaining time, we ensure accurate timeout calculations, preventing unnecessary CPU consumption during the main loop.
Related: OS#6339 Change-Id: I79de77c79af4d50d1eb9ca0c5417123ff760dca3 --- M src/core/timer.c 1 file changed, 28 insertions(+), 1 deletion(-)
git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/72/35672/1
diff --git a/src/core/timer.c b/src/core/timer.c index 20d87a0..4229c5a 100644 --- a/src/core/timer.c +++ b/src/core/timer.c @@ -190,8 +190,13 @@ if (!nearest_p) return -1;
+ /* By adding 999 milliseconds, we ensure rounding up to the nearest + * whole millisecond. This approach prevents the return of 0 when the + * timer is still active, and it guarantees that the calling process + * does not wait for a duration shorter than the time remaining on the + * timer. */ nearest_ms = nearest_p->tv_sec * 1000; - nearest_ms += nearest_p->tv_usec / 1000; + nearest_ms += (nearest_p->tv_usec + 999) / 1000;
return nearest_ms; }