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| author | Juri Lelli <juri.lelli@gmail.com> | 2013-11-07 14:43:47 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-01-13 13:46:46 +0100 |
| commit | 6bfd6d72f51c51177676f2b1ba113fe0a85fdae4 (patch) | |
| tree | 8c3c4c49f18ba3218da4274623b50da0a317f2d6 /kernel/sched/core.c | |
| parent | 332ac17ef5bfcff4766dfdfd3b4cdf10b8f8f155 (diff) | |
| download | lwn-6bfd6d72f51c51177676f2b1ba113fe0a85fdae4.tar.gz lwn-6bfd6d72f51c51177676f2b1ba113fe0a85fdae4.zip | |
sched/deadline: speed up SCHED_DEADLINE pushes with a push-heap
Data from tests confirmed that the original active load balancing
logic didn't scale neither in the number of CPU nor in the number of
tasks (as sched_rt does).
Here we provide a global data structure to keep track of deadlines
of the running tasks in the system. The structure is composed by
a bitmask showing the free CPUs and a max-heap, needed when the system
is heavily loaded.
The implementation and concurrent access scheme are kept simple by
design. However, our measurements show that we can compete with sched_rt
on large multi-CPUs machines [1].
Only the push path is addressed, the extension to use this structure
also for pull decisions is straightforward. However, we are currently
evaluating different (in order to decrease/avoid contention) data
structures to solve possibly both problems. We are also going to re-run
tests considering recent changes inside cpupri [2].
[1] http://retis.sssup.it/~jlelli/papers/Ospert11Lelli.pdf
[2] http://www.spinics.net/lists/linux-rt-users/msg06778.html
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1383831828-15501-14-git-send-email-juri.lelli@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/core.c')
| -rw-r--r-- | kernel/sched/core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c7c68e6b5c51..e30356d6b31f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5287,6 +5287,7 @@ static void free_rootdomain(struct rcu_head *rcu) struct root_domain *rd = container_of(rcu, struct root_domain, rcu); cpupri_cleanup(&rd->cpupri); + cpudl_cleanup(&rd->cpudl); free_cpumask_var(rd->dlo_mask); free_cpumask_var(rd->rto_mask); free_cpumask_var(rd->online); @@ -5345,6 +5346,8 @@ static int init_rootdomain(struct root_domain *rd) goto free_dlo_mask; init_dl_bw(&rd->dl_bw); + if (cpudl_init(&rd->cpudl) != 0) + goto free_dlo_mask; if (cpupri_init(&rd->cpupri) != 0) goto free_rto_mask; |