Messages in this thread | | | Date | Fri, 17 Aug 2018 15:24:15 +0100 | From | Patrick Bellasi <> | Subject | Re: [PATCH v3 08/14] sched/core: uclamp: extend cpu's cgroup controller |
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On 17-Aug 14:21, Dietmar Eggemann wrote: > On 08/06/2018 06:39 PM, Patrick Bellasi wrote: > > [...] > > >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.
> [...] > > >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
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