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author | Tudor Florea <tudor.florea@enea.com> | 2014-10-10 03:19:52 +0200 |
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committer | Tudor Florea <tudor.florea@enea.com> | 2014-10-10 03:19:52 +0200 |
commit | 7ac6af29202ec27dcdbf1ed5131a141be9958590 (patch) | |
tree | a20c0be935ea685b3b737471e691d39289c2333f /recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch | |
download | meta-nohz-daisy-140929.tar.gz |
initial commit for Enea Linux 4.0-140929daisy-140929
Migrated from the internal git server on the daisy-enea-point-release branch
Signed-off-by: Tudor Florea <tudor.florea@enea.com>
Diffstat (limited to 'recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch')
-rw-r--r-- | recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch b/recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch new file mode 100644 index 0000000..349604c --- /dev/null +++ b/recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch | |||
@@ -0,0 +1,61 @@ | |||
1 | From 92f0d4f695198fcb935cf0360f93a15bf0a6af1e Mon Sep 17 00:00:00 2001 | ||
2 | From: Kevin Hilman <khilman@linaro.org> | ||
3 | Date: Mon, 16 Sep 2013 15:43:48 -0700 | ||
4 | Subject: [PATCH 3/3] sched/nohz: add debugfs control over | ||
5 | sched_tick_max_deferment | ||
6 | |||
7 | Allow debugfs override of sched_tick_max_deferment in order to ease | ||
8 | finding/fixing the remaining issues with full nohz. | ||
9 | |||
10 | The value to be written is in jiffies, and -1 means the max deferment | ||
11 | is disabled (scheduler_tick_max_deferment() returns KTIME_MAX.) | ||
12 | |||
13 | Cc: Frederic Weisbecker <fweisbec@gmail.com> | ||
14 | Signed-off-by: Kevin Hilman <khilman@linaro.org> | ||
15 | --- | ||
16 | kernel/sched/core.c | 16 +++++++++++++++- | ||
17 | 1 file changed, 15 insertions(+), 1 deletion(-) | ||
18 | |||
19 | diff --git a/kernel/sched/core.c b/kernel/sched/core.c | ||
20 | index e8b3350..59c7367 100644 | ||
21 | --- a/kernel/sched/core.c | ||
22 | +++ b/kernel/sched/core.c | ||
23 | @@ -2753,6 +2753,8 @@ void scheduler_tick(void) | ||
24 | } | ||
25 | |||
26 | #ifdef CONFIG_NO_HZ_FULL | ||
27 | +static u32 sched_tick_max_deferment = HZ; | ||
28 | + | ||
29 | /** | ||
30 | * scheduler_tick_max_deferment | ||
31 | * | ||
32 | @@ -2769,13 +2771,25 @@ u64 scheduler_tick_max_deferment(void) | ||
33 | struct rq *rq = this_rq(); | ||
34 | unsigned long next, now = ACCESS_ONCE(jiffies); | ||
35 | |||
36 | - next = rq->last_sched_tick + HZ; | ||
37 | + if (sched_tick_max_deferment == -1) | ||
38 | + return KTIME_MAX; | ||
39 | + | ||
40 | + next = rq->last_sched_tick + sched_tick_max_deferment; | ||
41 | |||
42 | if (time_before_eq(next, now)) | ||
43 | return 0; | ||
44 | |||
45 | return jiffies_to_usecs(next - now) * NSEC_PER_USEC; | ||
46 | } | ||
47 | + | ||
48 | +static __init int sched_nohz_full_init_debug(void) | ||
49 | +{ | ||
50 | + debugfs_create_u32("sched_tick_max_deferment", 0644, NULL, | ||
51 | + &sched_tick_max_deferment); | ||
52 | + | ||
53 | + return 0; | ||
54 | +} | ||
55 | +late_initcall(sched_nohz_full_init_debug); | ||
56 | #endif | ||
57 | |||
58 | notrace unsigned long get_parent_ip(unsigned long addr) | ||
59 | -- | ||
60 | 1.7.10.4 | ||
61 | |||