lwn.git/kernel, branch v2.6.23-rc4

fix bogus hotplug cpu warning

2007-08-27T17:27:48+00:00

Fix bogus DEBUG_PREEMPT warning on x86_64, when cpu brought online after bootup: current_is_keventd is right to note its use of smp_processor_id is preempt-safe, but should use raw_smp_processor_id to avoid the warning. Signed-off-by: Hugh Dickins Signed-off-by: Linus Torvalds

sched: s/sched_latency/sched_min_granularity

2007-08-25T20:17:19+00:00

runtime limit and wakeup granularity used to be a function of granularity and that was incorrect changed to sched_latency. Fix this to make wakeup granularity a function of min-granularity, and the runtime limit equal to latency. Signed-off-by: Ingo Molnar

sched: cleanup, sched_granularity -> sched_min_granularity

2007-08-25T16:41:53+00:00

due to adaptive granularity scheduling the role of sched_granularity has changed to "minimum granularity", so rename the variable (and the tunable) accordingly. Signed-off-by: Ingo Molnar Signed-off-by: Peter Zijlstra

sched: adaptive scheduler granularity

2007-08-25T16:41:53+00:00

Instead of specifying the preemption granularity, specify the wanted latency. By fixing the granlarity to a constany the wakeup latency it a function of the number of running tasks on the rq. Invert this relation. sysctl_sched_granularity becomes a minimum for the dynamic granularity computed from the new sysctl_sched_latency. Then use this latency to do more intelligent granularity decisions: if there are fewer tasks running then we can schedule coarser. This helps performance while still always keeping the latency target. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar

sched: fix CONFIG_SCHED_DEBUG dependency of lockdep sysctls

2007-08-25T16:41:52+00:00

Make the lockdep sysctls not depend on CONFIG_SCHED_DEBUG. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar

sched: fix startup penalty calculation

2007-08-24T18:39:10+00:00

fix task startup penalty miscalculation: sysctl_sched_granularity is unsigned int and wait_runtime is long so we first have to convert it to long before turning it negative ... Signed-off-by: Ingo Molnar

sched: simplify bonus calculation #2

2007-08-24T18:39:10+00:00

current code: delta = calc_delta_mine(delta_exec, curr->load.weight, lw); delta = min((u64)delta, cfs_rq->sleeper_bonus); Notice that this calc_delta_mine() line is exactly delta_mine, which gives: delta = min((u64)delta_mine, cfs_rq->sleeper_bonus); Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar

sched: simplify bonus calculation #1

2007-08-24T18:39:10+00:00

current code: delta = min(cfs_rq->sleeper_bonus, (u64)delta_exec); delta = calc_delta_mine(delta, curr->load.weight, lw); delta = min((u64)delta, cfs_rq->sleeper_bonus); drop the first min(), because we clip against sleeper_bonus in the 3rd line again. That gives: delta = calc_delta_mine(delta_exec, curr->load.weight, lw); delta = min((u64)delta, cfs_rq->sleeper_bonus); Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar

sched: tidy up and simplify the bonus balance

2007-08-24T18:39:10+00:00

make the bonus balance more consistent: do not hand out a bonus if there's too much in flight already, and only deduct as much from a runner as it has the capacity. This makes the bonus engine a zero-sum game (as intended). this also simplifies the code: text data bss dec hex filename 34770 2998 24 37792 93a0 sched.o.before 34749 2998 24 37771 938b sched.o.after and it also avoids overscheduling in sleep-happy workloads like hackbench.c. Signed-off-by: Ingo Molnar

sched: optimize task_tick_rt() a bit

2007-08-24T18:39:10+00:00

Mitchell Erblich suggested a quality-of-implementation change to not requeue SCHED_RR tasks if there's only a single task on the runqueue, by checking for rq->nr_running == 1. provide a more efficient implementation of that, to check that particular RT priority-queue only. [ From: mingo@elte.hu ] Also first requeue the task then set need_resched - results in slightly better machine-instruction ordering. Also clean up the code a bit. Signed-off-by: Dmitry Adamushko Signed-off-by: Ingo Molnar