Frederic Weisbecker fweisbec@gmail.com writes:
On Tue, Jun 18, 2013 at 04:58:28PM -0700, Kevin Hilman wrote:
Allow sysctl override of sched_tick_max_deferment in order to ease finding/fixing the remaining issues with full nohz.
The value to be written is in jiffies, and -1 means the max deferment is disabled (scheduler_tick_max_deferment() returns KTIME_MAX.)
Cc: Frederic Weisbecker fweisbec@gmail.com Signed-off-by: Kevin Hilman khilman@linaro.org
This looks like a useful thing but I wonder if a debugfs file would be more appropriate than sysctl.
The scheduler tick max deferment is supposed to be a temporary hack so we probably don't want to bring a real user ABI for that.
I wondered about that as well, but I wasn't sure if the existing knobs under CONFIG_SCHED_DEBUG (sched_min_granularity_ns, sched_latency_ns, etc.) are considered permanant ABI, or optional debugging tools.
This new option is inside CONFIG_SCHED_DEBUG along with the others, but if debugfs is preferred I can move it there. It seems strange though to just have this knob in debugfs and the rest in sysctl under CONFIG_SCHED_DEBUG.
Thanks,
Kevin