From b61ccd5d9d368f3fbbae27ce14ac02a3db1884c4 Mon Sep 17 00:00:00 2001 From: Adam Jackson Date: Tue, 5 Nov 2013 10:20:04 -0500 Subject: [PATCH] smartsched: Tweak the default scheduler intervals A default timeslice of 20ms means a pathological client can ruin up to two frames per scheduler tick. And a fifth of a second is just insane. Pick two different numbers out of the hat. A 5ms slice means you can probably keep up with two or three abusive clients, and letting it burst to 15ms should give you about all the timeslice you need for a fullscreen game (that's doing server-side rendering for some reason). If you're running on a system with a 10ms granularity on SIGALRM, then this effectively changes the intervals to 10ms and 30ms. Which is still better, just not as better. I suspect this is about as good as we can do without actually going preemptive, which is an entire other nightmare. Reviewed-by: Julien Cristau Signed-off-by: Adam Jackson --- dix/dispatch.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/dix/dispatch.c b/dix/dispatch.c index 4fecfea7b..8dcd9cbcf 100644 --- a/dix/dispatch.c +++ b/dix/dispatch.c @@ -220,8 +220,9 @@ UpdateCurrentTimeIf(void) #undef SMART_DEBUG -#define SMART_SCHEDULE_DEFAULT_INTERVAL 20 /* ms */ -#define SMART_SCHEDULE_MAX_SLICE 200 /* ms */ +/* in milliseconds */ +#define SMART_SCHEDULE_DEFAULT_INTERVAL 5 +#define SMART_SCHEDULE_MAX_SLICE 15 #if defined(WIN32) && !defined(__CYGWIN__) Bool SmartScheduleDisable = TRUE;