Re: [PATCH v3 08/14] sched/core: uclamp: extend cpu's cgroup controller
From: Patrick Bellasi <hidden>
Date: 2018-08-17 14:24:23
Also in:
lkml
On 17-Aug 14:21, Dietmar Eggemann wrote:
On 08/06/2018 06:39 PM, Patrick Bellasi wrote: [...]quoted
Give the above mechanisms, it is now possible to extend the cpu controller to specify what is the minimum (or maximum) utilization which a task is expected (or allowed) to generate. Constraints on minimum and maximum utilization allowed for tasks in a CPU cgroup can improve the control on the actual amount of CPU bandwidth consumed by tasks.I assume this is covered by the s/bandwidth/capacity/ you had w/ Juri on 01/14.
Yes... I need to update this changelog too.
quoted hunk ↗ jump to hunk
[...]quoted
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ff76b000bbe8..2ba55a4afffb 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c@@ -1211,6 +1211,74 @@ static inline void uclamp_group_get(struct task_struct *p, uclamp_group_put(clamp_id, prev_group_id); } +#ifdef CONFIG_UCLAMP_TASK_GROUP +/** + * init_uclamp_sched_group: initialize data structures required for TG's + * utilization clamping + */ +static inline void init_uclamp_sched_group(void) +{ + struct uclamp_map *uc_map; + struct uclamp_se *uc_se; + int group_id; + int clamp_id; + + /* Root TG's is statically assigned to the first clamp group */ + group_id = 0; + + /* Initialize root TG's to default (none) clamp values */ + for (clamp_id = 0; clamp_id < UCLAMP_CNT; ++clamp_id) { + uc_map = &uclamp_maps[clamp_id][0]; + + /* Map root TG's clamp value */ + uclamp_group_init(clamp_id, group_id, uclamp_none(clamp_id)); + + /* Init root TG's clamp group */ + uc_se = &root_task_group.uclamp[clamp_id]; + uc_se->value = uclamp_none(clamp_id); + uc_se->group_id = group_id; + + /* Attach root TG's clamp group */ + uc_map[group_id].se_count = 1; + } +}Can you not save some lines here: static inline void init_uclamp_sched_group(void) { - struct uclamp_map *uc_map; struct uclamp_se *uc_se; int group_id; int clamp_id;@@ -1228,8 +1227,6 @@ static inline void init_uclamp_sched_group(void) /* Initialize root TG's to default (none) clamp values */ for (clamp_id = 0; clamp_id < UCLAMP_CNT; ++clamp_id) { - uc_map = &uclamp_maps[clamp_id][0]; - /* Map root TG's clamp value */ uclamp_group_init(clamp_id, group_id,uclamp_none(clamp_id));@@ -1239,7 +1236,7 @@ static inline void init_uclamp_sched_group(void) uc_se->group_id = group_id; /* Attach root TG's clamp group */ - uc_map[group_id].se_count = 1; + uclamp_maps[clamp_id][group_id].se_count = 1; }This would also make uclamp_group_available() smaller.
Unfortunately this var name and its matrix indexes tends to become quite long easily and in some usages we exceed the 80 columns sometimes. That's why, for consistency, I always shortcut to *uc_map a reference to a clamp group and use that variable name consistently in the code. I'll see if it's possible to get rid of the shortcut in the next version. -- #include <best/regards.h> Patrick Bellasi