Hello,
Thanks Gregory for clarifying my question on root_domains infrastructure. What
I was effectively mentioning on irc the other day was to make the root_domain
infrastructure modular, ie sched_class specific. Currently, only rt is making
use of this infrasture. Making it modular would enable ease of extension to
other sched_classes if required. Trivial patch to that effect.
Patch compile and boot tested.
Signed-off-by: Ankita Garg <[email protected]>
Index: linux-2.6.24.3-rt3/kernel/sched.c
===================================================================
--- linux-2.6.24.3-rt3.orig/kernel/sched.c 2008-03-21 22:57:04.000000000 +0530
+++ linux-2.6.24.3-rt3/kernel/sched.c 2008-03-21 23:04:56.000000000 +0530
@@ -337,11 +337,8 @@
* object.
*
*/
-struct root_domain {
- atomic_t refcount;
- cpumask_t span;
- cpumask_t online;
+struct rt_root_domain {
/*
* The "RT overload" flag: it gets set if a CPU has more than
* one runnable RT task.
@@ -353,6 +350,14 @@
#endif
};
+struct root_domain {
+ atomic_t refcount;
+ cpumask_t span;
+ cpumask_t online;
+
+ struct rt_root_domain rt_dom;
+};
+
/*
* By default the system creates a single root-domain with all cpus as
* members (mimicking the global state we have today).
@@ -6332,7 +6337,7 @@
cpus_clear(rd->span);
cpus_clear(rd->online);
- cpupri_init(&rd->cpupri);
+ cpupri_init(&rd->rt_dom.cpupri);
}
Index: linux-2.6.24.3-rt3/kernel/sched_rt.c
===================================================================
--- linux-2.6.24.3-rt3.orig/kernel/sched_rt.c 2008-03-21 22:57:04.000000000 +0530
+++ linux-2.6.24.3-rt3/kernel/sched_rt.c 2008-03-21 23:04:39.000000000 +0530
@@ -7,12 +7,12 @@
static inline int rt_overloaded(struct rq *rq)
{
- return atomic_read(&rq->rd->rto_count);
+ return atomic_read(&rq->rd->rt_dom.rto_count);
}
static inline void rt_set_overload(struct rq *rq)
{
- cpu_set(rq->cpu, rq->rd->rto_mask);
+ cpu_set(rq->cpu, rq->rd->rt_dom.rto_mask);
/*
* Make sure the mask is visible before we set
* the overload count. That is checked to determine
@@ -21,14 +21,14 @@
* updated yet.
*/
wmb();
- atomic_inc(&rq->rd->rto_count);
+ atomic_inc(&rq->rd->rt_dom.rto_count);
}
static inline void rt_clear_overload(struct rq *rq)
{
/* the order here really doesn't matter */
- atomic_dec(&rq->rd->rto_count);
- cpu_clear(rq->cpu, rq->rd->rto_mask);
+ atomic_dec(&rq->rd->rt_dom.rto_count);
+ cpu_clear(rq->cpu, rq->rd->rt_dom.rto_mask);
}
static void update_rt_migration(struct rq *rq)
@@ -78,7 +78,7 @@
#ifdef CONFIG_SMP
if (p->prio < rq->rt.highest_prio) {
rq->rt.highest_prio = p->prio;
- cpupri_set(&rq->rd->cpupri, rq->cpu, p->prio);
+ cpupri_set(&rq->rd->rt_dom.cpupri, rq->cpu, p->prio);
}
if (p->nr_cpus_allowed > 1)
rq->rt.rt_nr_migratory++;
@@ -114,7 +114,7 @@
}
if (rq->rt.highest_prio != highest_prio)
- cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
+ cpupri_set(&rq->rd->rt_dom.cpupri, rq->cpu, rq->rt.highest_prio);
update_rt_migration(rq);
#endif /* CONFIG_SMP */
@@ -363,7 +363,7 @@
{
int count;
- count = cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask);
+ count = cpupri_find(&task_rq(task)->rd->rt_dom.cpupri, task, lowest_mask);
/*
* cpupri cannot efficiently tell us how many bits are set, so it only
@@ -599,7 +599,7 @@
next = pick_next_task_rt(this_rq);
- for_each_cpu_mask(cpu, this_rq->rd->rto_mask) {
+ for_each_cpu_mask(cpu, this_rq->rd->rt_dom.rto_mask) {
if (this_cpu == cpu)
continue;
@@ -763,7 +763,7 @@
if (rq->rt.overloaded)
rt_set_overload(rq);
- cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
+ cpupri_set(&rq->rd->rt_dom.cpupri, rq->cpu, rq->rt.highest_prio);
}
/* Assumes rq->lock is held */
@@ -772,7 +772,7 @@
if (rq->rt.overloaded)
rt_clear_overload(rq);
- cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
+ cpupri_set(&rq->rd->rt_dom.cpupri, rq->cpu, CPUPRI_INVALID);
}
/*
--
Regards,
Ankita Garg ([email protected])
Linux Technology Center
IBM India Systems & Technology Labs,
Bangalore, India
>>> On Sat, Mar 22, 2008 at 10:29 AM, in message
<[email protected]>, Ankita Garg <[email protected]> wrote:
> Hello,
>
> Thanks Gregory for clarifying my question on root_domains infrastructure.
> What
> I was effectively mentioning on irc the other day was to make the
> root_domain
> infrastructure modular, ie sched_class specific. Currently, only rt is
> making
> use of this infrasture. Making it modular would enable ease of extension to
> other sched_classes if required. Trivial patch to that effect.
>
> Patch compile and boot tested.
Hi Ankita,
Very nice, thanks! Couple of minor nits and further cleanup opportunities inline, but otherwise:
Acked-by: Gregory Haskins <[email protected]>
>
>
> Signed-off-by: Ankita Garg <[email protected]>
>
> Index: linux-2.6.24.3-rt3/kernel/sched.c
> ===================================================================
> --- linux-2.6.24.3-rt3.orig/kernel/sched.c 2008-03-21 22:57:04.000000000 +0530
> +++ linux-2.6.24.3-rt3/kernel/sched.c 2008-03-21 23:04:56.000000000 +0530
> @@ -337,11 +337,8 @@
> * object.
> *
> */
> -struct root_domain {
> - atomic_t refcount;
> - cpumask_t span;
> - cpumask_t online;
>
> +struct rt_root_domain {
> /*
> * The "RT overload" flag: it gets set if a CPU has more than
> * one runnable RT task.
> @@ -353,6 +350,14 @@
> #endif
> };
>
> +struct root_domain {
> + atomic_t refcount;
> + cpumask_t span;
> + cpumask_t online;
> +
> + struct rt_root_domain rt_dom;
Perhaps this should just be s/rt_dom/rt since it is already implicitly a domain just by being a subordinate member of a domain structure.
> +};
> +
> /*
> * By default the system creates a single root-domain with all cpus as
> * members (mimicking the global state we have today).
> @@ -6332,7 +6337,7 @@
> cpus_clear(rd->span);
> cpus_clear(rd->online);
>
> - cpupri_init(&rd->cpupri);
> + cpupri_init(&rd->rt_dom.cpupri);
>
> }
>
> Index: linux-2.6.24.3-rt3/kernel/sched_rt.c
> ===================================================================
> --- linux-2.6.24.3-rt3.orig/kernel/sched_rt.c 2008-03-21 22:57:04.000000000 +0530
> +++ linux-2.6.24.3-rt3/kernel/sched_rt.c 2008-03-21 23:04:39.000000000 +0530
> @@ -7,12 +7,12 @@
>
> static inline int rt_overloaded(struct rq *rq)
> {
> - return atomic_read(&rq->rd->rto_count);
> + return atomic_read(&rq->rd->rt_dom.rto_count);
Perhaps we should change s/rto_count/overload_count and s/rto_mask/overload_mask, since "rt" is now implicit with the association with rt_root_domain?
> }
>
> static inline void rt_set_overload(struct rq *rq)
> {
> - cpu_set(rq->cpu, rq->rd->rto_mask);
> + cpu_set(rq->cpu, rq->rd->rt_dom.rto_mask);
> /*
> * Make sure the mask is visible before we set
> * the overload count. That is checked to determine
> @@ -21,14 +21,14 @@
> * updated yet.
> */
> wmb();
> - atomic_inc(&rq->rd->rto_count);
> + atomic_inc(&rq->rd->rt_dom.rto_count);
> }
>
> static inline void rt_clear_overload(struct rq *rq)
> {
> /* the order here really doesn't matter */
> - atomic_dec(&rq->rd->rto_count);
> - cpu_clear(rq->cpu, rq->rd->rto_mask);
> + atomic_dec(&rq->rd->rt_dom.rto_count);
> + cpu_clear(rq->cpu, rq->rd->rt_dom.rto_mask);
> }
>
> static void update_rt_migration(struct rq *rq)
> @@ -78,7 +78,7 @@
> #ifdef CONFIG_SMP
> if (p->prio < rq->rt.highest_prio) {
> rq->rt.highest_prio = p->prio;
> - cpupri_set(&rq->rd->cpupri, rq->cpu, p->prio);
> + cpupri_set(&rq->rd->rt_dom.cpupri, rq->cpu, p->prio);
> }
> if (p->nr_cpus_allowed > 1)
> rq->rt.rt_nr_migratory++;
> @@ -114,7 +114,7 @@
> }
>
> if (rq->rt.highest_prio != highest_prio)
> - cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
> + cpupri_set(&rq->rd->rt_dom.cpupri, rq->cpu, rq->rt.highest_prio);
>
> update_rt_migration(rq);
> #endif /* CONFIG_SMP */
> @@ -363,7 +363,7 @@
> {
> int count;
>
> - count = cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask);
> + count = cpupri_find(&task_rq(task)->rd->rt_dom.cpupri, task, lowest_mask);
>
> /*
> * cpupri cannot efficiently tell us how many bits are set, so it only
> @@ -599,7 +599,7 @@
>
> next = pick_next_task_rt(this_rq);
>
> - for_each_cpu_mask(cpu, this_rq->rd->rto_mask) {
> + for_each_cpu_mask(cpu, this_rq->rd->rt_dom.rto_mask) {
> if (this_cpu == cpu)
> continue;
>
> @@ -763,7 +763,7 @@
> if (rq->rt.overloaded)
> rt_set_overload(rq);
>
> - cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
> + cpupri_set(&rq->rd->rt_dom.cpupri, rq->cpu, rq->rt.highest_prio);
> }
>
> /* Assumes rq->lock is held */
> @@ -772,7 +772,7 @@
> if (rq->rt.overloaded)
> rt_clear_overload(rq);
>
> - cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
> + cpupri_set(&rq->rd->rt_dom.cpupri, rq->cpu, CPUPRI_INVALID);
> }
>
> /*
Hi Gregory,
On Sat, Mar 22, 2008 at 12:04:04PM -0600, Gregory Haskins wrote:
> >>> On Sat, Mar 22, 2008 at 10:29 AM, in message
> <[email protected]>, Ankita Garg <[email protected]> wrote:
> > Hello,
> >
> > Thanks Gregory for clarifying my question on root_domains infrastructure.
> > What
> > I was effectively mentioning on irc the other day was to make the
> > root_domain
> > infrastructure modular, ie sched_class specific. Currently, only rt is
> > making
> > use of this infrasture. Making it modular would enable ease of extension to
> > other sched_classes if required. Trivial patch to that effect.
> >
> > Patch compile and boot tested.
>
> Hi Ankita,
> Very nice, thanks! Couple of minor nits and further cleanup opportunities inline, but otherwise:
>
> Acked-by: Gregory Haskins <[email protected]>
>
> >
The changes you have suggested are consistent with what we do for rt_rq
and cfs_rq. Here is the patch with these modifications.
Signed-off-by: Ankita Garg <[email protected]>
Index: linux-2.6.24.3-rt3/kernel/sched.c
===================================================================
--- linux-2.6.24.3-rt3.orig/kernel/sched.c 2008-03-21 22:57:04.000000000 +0530
+++ linux-2.6.24.3-rt3/kernel/sched.c 2008-03-23 14:09:22.000000000 +0530
@@ -337,22 +337,27 @@
* object.
*
*/
-struct root_domain {
- atomic_t refcount;
- cpumask_t span;
- cpumask_t online;
+struct rt_root_domain {
/*
* The "RT overload" flag: it gets set if a CPU has more than
* one runnable RT task.
*/
- cpumask_t rto_mask;
- atomic_t rto_count;
+ cpumask_t overload_mask;
+ atomic_t overload_count;
#ifdef CONFIG_SMP
struct cpupri cpupri;
#endif
};
+struct root_domain {
+ atomic_t refcount;
+ cpumask_t span;
+ cpumask_t online;
+
+ struct rt_root_domain rt;
+};
+
/*
* By default the system creates a single root-domain with all cpus as
* members (mimicking the global state we have today).
@@ -6332,7 +6337,7 @@
cpus_clear(rd->span);
cpus_clear(rd->online);
- cpupri_init(&rd->cpupri);
+ cpupri_init(&rd->rt.cpupri);
}
Index: linux-2.6.24.3-rt3/kernel/sched_rt.c
===================================================================
--- linux-2.6.24.3-rt3.orig/kernel/sched_rt.c 2008-03-21 22:57:04.000000000 +0530
+++ linux-2.6.24.3-rt3/kernel/sched_rt.c 2008-03-23 14:12:45.000000000 +0530
@@ -7,12 +7,12 @@
static inline int rt_overloaded(struct rq *rq)
{
- return atomic_read(&rq->rd->rto_count);
+ return atomic_read(&rq->rd->rt.overload_count);
}
static inline void rt_set_overload(struct rq *rq)
{
- cpu_set(rq->cpu, rq->rd->rto_mask);
+ cpu_set(rq->cpu, rq->rd->rt.overload_mask);
/*
* Make sure the mask is visible before we set
* the overload count. That is checked to determine
@@ -21,14 +21,14 @@
* updated yet.
*/
wmb();
- atomic_inc(&rq->rd->rto_count);
+ atomic_inc(&rq->rd->rt.overload_count);
}
static inline void rt_clear_overload(struct rq *rq)
{
/* the order here really doesn't matter */
- atomic_dec(&rq->rd->rto_count);
- cpu_clear(rq->cpu, rq->rd->rto_mask);
+ atomic_dec(&rq->rd->rt.overload_count);
+ cpu_clear(rq->cpu, rq->rd->rt.overload_mask);
}
static void update_rt_migration(struct rq *rq)
@@ -78,7 +78,7 @@
#ifdef CONFIG_SMP
if (p->prio < rq->rt.highest_prio) {
rq->rt.highest_prio = p->prio;
- cpupri_set(&rq->rd->cpupri, rq->cpu, p->prio);
+ cpupri_set(&rq->rd->rt.cpupri, rq->cpu, p->prio);
}
if (p->nr_cpus_allowed > 1)
rq->rt.rt_nr_migratory++;
@@ -114,7 +114,7 @@
}
if (rq->rt.highest_prio != highest_prio)
- cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
+ cpupri_set(&rq->rd->rt.cpupri, rq->cpu, rq->rt.highest_prio);
update_rt_migration(rq);
#endif /* CONFIG_SMP */
@@ -363,7 +363,7 @@
{
int count;
- count = cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask);
+ count = cpupri_find(&task_rq(task)->rd->rt.cpupri, task, lowest_mask);
/*
* cpupri cannot efficiently tell us how many bits are set, so it only
@@ -599,7 +599,7 @@
next = pick_next_task_rt(this_rq);
- for_each_cpu_mask(cpu, this_rq->rd->rto_mask) {
+ for_each_cpu_mask(cpu, this_rq->rd->rt.overload_mask) {
if (this_cpu == cpu)
continue;
@@ -763,7 +763,7 @@
if (rq->rt.overloaded)
rt_set_overload(rq);
- cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
+ cpupri_set(&rq->rd->rt.cpupri, rq->cpu, rq->rt.highest_prio);
}
/* Assumes rq->lock is held */
@@ -772,7 +772,7 @@
if (rq->rt.overloaded)
rt_clear_overload(rq);
- cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
+ cpupri_set(&rq->rd->rt.cpupri, rq->cpu, CPUPRI_INVALID);
}
/*
--
Regards,
Ankita Garg ([email protected])
Linux Technology Center
IBM India Systems & Technology Labs,
Bangalore, India
On Sun, 2008-03-23 at 14:32 +0530, Ankita Garg wrote:
> Hi Gregory,
>
> On Sat, Mar 22, 2008 at 12:04:04PM -0600, Gregory Haskins wrote:
> > >>> On Sat, Mar 22, 2008 at 10:29 AM, in message
> > <[email protected]>, Ankita Garg <[email protected]> wrote:
> > > Hello,
> > >
> > > Thanks Gregory for clarifying my question on root_domains infrastructure.
> > > What
> > > I was effectively mentioning on irc the other day was to make the
> > > root_domain
> > > infrastructure modular, ie sched_class specific. Currently, only rt is
> > > making
> > > use of this infrasture. Making it modular would enable ease of extension to
> > > other sched_classes if required. Trivial patch to that effect.
> > >
> > > Patch compile and boot tested.
> >
> > Hi Ankita,
> > Very nice, thanks! Couple of minor nits and further cleanup opportunities inline, but otherwise:
> >
> > Acked-by: Gregory Haskins <[email protected]>
> >
> > >
> The changes you have suggested are consistent with what we do for rt_rq
> and cfs_rq. Here is the patch with these modifications.
As this patch doesn't touch -rt specific code you should have provided a
patch against the upstream code in sched-devel/latest.
patching file kernel/sched.c
Hunk #1 FAILED at 337.
Hunk #2 FAILED at 6337.
2 out of 2 hunks FAILED -- rejects in file kernel/sched.c
patching file kernel/sched_rt.c
Hunk #3 FAILED at 78.
Hunk #4 FAILED at 114.
Hunk #5 FAILED at 363.
Hunk #6 succeeded at 1005 (offset 406 lines).
Hunk #7 FAILED at 1169.
Hunk #8 FAILED at 1178.
5 out of 8 hunks FAILED -- rejects in file kernel/sched_rt.c
> Signed-off-by: Ankita Garg <[email protected]>
>
> Index: linux-2.6.24.3-rt3/kernel/sched.c
> ===================================================================
> --- linux-2.6.24.3-rt3.orig/kernel/sched.c 2008-03-21 22:57:04.000000000 +0530
> +++ linux-2.6.24.3-rt3/kernel/sched.c 2008-03-23 14:09:22.000000000 +0530
> @@ -337,22 +337,27 @@
> * object.
> *
> */
> -struct root_domain {
> - atomic_t refcount;
> - cpumask_t span;
> - cpumask_t online;
>
> +struct rt_root_domain {
> /*
> * The "RT overload" flag: it gets set if a CPU has more than
> * one runnable RT task.
> */
> - cpumask_t rto_mask;
> - atomic_t rto_count;
> + cpumask_t overload_mask;
> + atomic_t overload_count;
> #ifdef CONFIG_SMP
> struct cpupri cpupri;
> #endif
> };
>
> +struct root_domain {
> + atomic_t refcount;
> + cpumask_t span;
> + cpumask_t online;
> +
> + struct rt_root_domain rt;
> +};
> +
> /*
> * By default the system creates a single root-domain with all cpus as
> * members (mimicking the global state we have today).
> @@ -6332,7 +6337,7 @@
> cpus_clear(rd->span);
> cpus_clear(rd->online);
>
> - cpupri_init(&rd->cpupri);
> + cpupri_init(&rd->rt.cpupri);
>
> }
>
> Index: linux-2.6.24.3-rt3/kernel/sched_rt.c
> ===================================================================
> --- linux-2.6.24.3-rt3.orig/kernel/sched_rt.c 2008-03-21 22:57:04.000000000 +0530
> +++ linux-2.6.24.3-rt3/kernel/sched_rt.c 2008-03-23 14:12:45.000000000 +0530
> @@ -7,12 +7,12 @@
>
> static inline int rt_overloaded(struct rq *rq)
> {
> - return atomic_read(&rq->rd->rto_count);
> + return atomic_read(&rq->rd->rt.overload_count);
> }
>
> static inline void rt_set_overload(struct rq *rq)
> {
> - cpu_set(rq->cpu, rq->rd->rto_mask);
> + cpu_set(rq->cpu, rq->rd->rt.overload_mask);
> /*
> * Make sure the mask is visible before we set
> * the overload count. That is checked to determine
> @@ -21,14 +21,14 @@
> * updated yet.
> */
> wmb();
> - atomic_inc(&rq->rd->rto_count);
> + atomic_inc(&rq->rd->rt.overload_count);
> }
>
> static inline void rt_clear_overload(struct rq *rq)
> {
> /* the order here really doesn't matter */
> - atomic_dec(&rq->rd->rto_count);
> - cpu_clear(rq->cpu, rq->rd->rto_mask);
> + atomic_dec(&rq->rd->rt.overload_count);
> + cpu_clear(rq->cpu, rq->rd->rt.overload_mask);
> }
>
> static void update_rt_migration(struct rq *rq)
> @@ -78,7 +78,7 @@
> #ifdef CONFIG_SMP
> if (p->prio < rq->rt.highest_prio) {
> rq->rt.highest_prio = p->prio;
> - cpupri_set(&rq->rd->cpupri, rq->cpu, p->prio);
> + cpupri_set(&rq->rd->rt.cpupri, rq->cpu, p->prio);
> }
> if (p->nr_cpus_allowed > 1)
> rq->rt.rt_nr_migratory++;
> @@ -114,7 +114,7 @@
> }
>
> if (rq->rt.highest_prio != highest_prio)
> - cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
> + cpupri_set(&rq->rd->rt.cpupri, rq->cpu, rq->rt.highest_prio);
>
> update_rt_migration(rq);
> #endif /* CONFIG_SMP */
> @@ -363,7 +363,7 @@
> {
> int count;
>
> - count = cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask);
> + count = cpupri_find(&task_rq(task)->rd->rt.cpupri, task, lowest_mask);
>
> /*
> * cpupri cannot efficiently tell us how many bits are set, so it only
> @@ -599,7 +599,7 @@
>
> next = pick_next_task_rt(this_rq);
>
> - for_each_cpu_mask(cpu, this_rq->rd->rto_mask) {
> + for_each_cpu_mask(cpu, this_rq->rd->rt.overload_mask) {
> if (this_cpu == cpu)
> continue;
>
> @@ -763,7 +763,7 @@
> if (rq->rt.overloaded)
> rt_set_overload(rq);
>
> - cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
> + cpupri_set(&rq->rd->rt.cpupri, rq->cpu, rq->rt.highest_prio);
> }
>
> /* Assumes rq->lock is held */
> @@ -772,7 +772,7 @@
> if (rq->rt.overloaded)
> rt_clear_overload(rq);
>
> - cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
> + cpupri_set(&rq->rd->rt.cpupri, rq->cpu, CPUPRI_INVALID);
> }
>
> /*
>
Hi Peter,
On Sun, Mar 23, 2008 at 12:27:07PM +0100, Peter Zijlstra wrote:
> On Sun, 2008-03-23 at 14:32 +0530, Ankita Garg wrote:
> > Hi Gregory,
> >
> > On Sat, Mar 22, 2008 at 12:04:04PM -0600, Gregory Haskins wrote:
> > > >>> On Sat, Mar 22, 2008 at 10:29 AM, in message
> > > <[email protected]>, Ankita Garg <[email protected]> wrote:
> > > > Hello,
> > > >
> > > > Thanks Gregory for clarifying my question on root_domains infrastructure.
> > > > What
> > > > I was effectively mentioning on irc the other day was to make the
> > > > root_domain
> > > > infrastructure modular, ie sched_class specific. Currently, only rt is
> > > > making
> > > > use of this infrasture. Making it modular would enable ease of extension to
> > > > other sched_classes if required. Trivial patch to that effect.
> > > >
> > > > Patch compile and boot tested.
> > >
> > > Hi Ankita,
> > > Very nice, thanks! Couple of minor nits and further cleanup opportunities inline, but otherwise:
> > >
> > > Acked-by: Gregory Haskins <[email protected]>
> > >
> > > >
> > The changes you have suggested are consistent with what we do for rt_rq
> > and cfs_rq. Here is the patch with these modifications.
>
> As this patch doesn't touch -rt specific code you should have provided a
> patch against the upstream code in sched-devel/latest.
>
The cpupri bits have not been added to the sched-devel tree yet. This
patch involves linking to the cpupri from the rt_root_domain. Thus the
patch against the latest RT tree. Pl let me know if I understand it
incorrectly.
> patching file kernel/sched.c
> Hunk #1 FAILED at 337.
> Hunk #2 FAILED at 6337.
> 2 out of 2 hunks FAILED -- rejects in file kernel/sched.c
> patching file kernel/sched_rt.c
> Hunk #3 FAILED at 78.
> Hunk #4 FAILED at 114.
> Hunk #5 FAILED at 363.
> Hunk #6 succeeded at 1005 (offset 406 lines).
> Hunk #7 FAILED at 1169.
> Hunk #8 FAILED at 1178.
> 5 out of 8 hunks FAILED -- rejects in file kernel/sched_rt.c
>
>
> > Signed-off-by: Ankita Garg <[email protected]>
> >
> > Index: linux-2.6.24.3-rt3/kernel/sched.c
> > ===================================================================
> > --- linux-2.6.24.3-rt3.orig/kernel/sched.c 2008-03-21 22:57:04.000000000 +0530
> > +++ linux-2.6.24.3-rt3/kernel/sched.c 2008-03-23 14:09:22.000000000 +0530
> > @@ -337,22 +337,27 @@
> > * object.
> > *
> > */
> > -struct root_domain {
> > - atomic_t refcount;
> > - cpumask_t span;
> > - cpumask_t online;
> >
> > +struct rt_root_domain {
> > /*
> > * The "RT overload" flag: it gets set if a CPU has more than
> > * one runnable RT task.
> > */
> > - cpumask_t rto_mask;
> > - atomic_t rto_count;
> > + cpumask_t overload_mask;
> > + atomic_t overload_count;
> > #ifdef CONFIG_SMP
> > struct cpupri cpupri;
> > #endif
> > };
> >
> > +struct root_domain {
> > + atomic_t refcount;
> > + cpumask_t span;
> > + cpumask_t online;
> > +
> > + struct rt_root_domain rt;
> > +};
> > +
> > /*
> > * By default the system creates a single root-domain with all cpus as
> > * members (mimicking the global state we have today).
> > @@ -6332,7 +6337,7 @@
> > cpus_clear(rd->span);
> > cpus_clear(rd->online);
> >
> > - cpupri_init(&rd->cpupri);
> > + cpupri_init(&rd->rt.cpupri);
> >
> > }
> >
> > Index: linux-2.6.24.3-rt3/kernel/sched_rt.c
> > ===================================================================
> > --- linux-2.6.24.3-rt3.orig/kernel/sched_rt.c 2008-03-21 22:57:04.000000000 +0530
> > +++ linux-2.6.24.3-rt3/kernel/sched_rt.c 2008-03-23 14:12:45.000000000 +0530
> > @@ -7,12 +7,12 @@
> >
> > static inline int rt_overloaded(struct rq *rq)
> > {
> > - return atomic_read(&rq->rd->rto_count);
> > + return atomic_read(&rq->rd->rt.overload_count);
> > }
> >
> > static inline void rt_set_overload(struct rq *rq)
> > {
> > - cpu_set(rq->cpu, rq->rd->rto_mask);
> > + cpu_set(rq->cpu, rq->rd->rt.overload_mask);
> > /*
> > * Make sure the mask is visible before we set
> > * the overload count. That is checked to determine
> > @@ -21,14 +21,14 @@
> > * updated yet.
> > */
> > wmb();
> > - atomic_inc(&rq->rd->rto_count);
> > + atomic_inc(&rq->rd->rt.overload_count);
> > }
> >
> > static inline void rt_clear_overload(struct rq *rq)
> > {
> > /* the order here really doesn't matter */
> > - atomic_dec(&rq->rd->rto_count);
> > - cpu_clear(rq->cpu, rq->rd->rto_mask);
> > + atomic_dec(&rq->rd->rt.overload_count);
> > + cpu_clear(rq->cpu, rq->rd->rt.overload_mask);
> > }
> >
> > static void update_rt_migration(struct rq *rq)
> > @@ -78,7 +78,7 @@
> > #ifdef CONFIG_SMP
> > if (p->prio < rq->rt.highest_prio) {
> > rq->rt.highest_prio = p->prio;
> > - cpupri_set(&rq->rd->cpupri, rq->cpu, p->prio);
> > + cpupri_set(&rq->rd->rt.cpupri, rq->cpu, p->prio);
> > }
> > if (p->nr_cpus_allowed > 1)
> > rq->rt.rt_nr_migratory++;
> > @@ -114,7 +114,7 @@
> > }
> >
> > if (rq->rt.highest_prio != highest_prio)
> > - cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
> > + cpupri_set(&rq->rd->rt.cpupri, rq->cpu, rq->rt.highest_prio);
> >
> > update_rt_migration(rq);
> > #endif /* CONFIG_SMP */
> > @@ -363,7 +363,7 @@
> > {
> > int count;
> >
> > - count = cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask);
> > + count = cpupri_find(&task_rq(task)->rd->rt.cpupri, task, lowest_mask);
> >
> > /*
> > * cpupri cannot efficiently tell us how many bits are set, so it only
> > @@ -599,7 +599,7 @@
> >
> > next = pick_next_task_rt(this_rq);
> >
> > - for_each_cpu_mask(cpu, this_rq->rd->rto_mask) {
> > + for_each_cpu_mask(cpu, this_rq->rd->rt.overload_mask) {
> > if (this_cpu == cpu)
> > continue;
> >
> > @@ -763,7 +763,7 @@
> > if (rq->rt.overloaded)
> > rt_set_overload(rq);
> >
> > - cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio);
> > + cpupri_set(&rq->rd->rt.cpupri, rq->cpu, rq->rt.highest_prio);
> > }
> >
> > /* Assumes rq->lock is held */
> > @@ -772,7 +772,7 @@
> > if (rq->rt.overloaded)
> > rt_clear_overload(rq);
> >
> > - cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
> > + cpupri_set(&rq->rd->rt.cpupri, rq->cpu, CPUPRI_INVALID);
> > }
> >
> > /*
> >
--
Regards,
Ankita Garg ([email protected])
Linux Technology Center
IBM India Systems & Technology Labs,
Bangalore, India
On Sun, 2008-03-23 at 17:07 +0530, Ankita Garg wrote:
> Hi Peter,
>
> On Sun, Mar 23, 2008 at 12:27:07PM +0100, Peter Zijlstra wrote:
> > On Sun, 2008-03-23 at 14:32 +0530, Ankita Garg wrote:
> > > Hi Gregory,
> > >
> > > On Sat, Mar 22, 2008 at 12:04:04PM -0600, Gregory Haskins wrote:
> > > > >>> On Sat, Mar 22, 2008 at 10:29 AM, in message
> > > > <[email protected]>, Ankita Garg <[email protected]> wrote:
> > > > > Hello,
> > > > >
> > > > > Thanks Gregory for clarifying my question on root_domains infrastructure.
> > > > > What
> > > > > I was effectively mentioning on irc the other day was to make the
> > > > > root_domain
> > > > > infrastructure modular, ie sched_class specific. Currently, only rt is
> > > > > making
> > > > > use of this infrasture. Making it modular would enable ease of extension to
> > > > > other sched_classes if required. Trivial patch to that effect.
> > > > >
> > > > > Patch compile and boot tested.
> > > >
> > > > Hi Ankita,
> > > > Very nice, thanks! Couple of minor nits and further cleanup opportunities inline, but otherwise:
> > > >
> > > > Acked-by: Gregory Haskins <[email protected]>
> > > >
> > > > >
> > > The changes you have suggested are consistent with what we do for rt_rq
> > > and cfs_rq. Here is the patch with these modifications.
> >
> > As this patch doesn't touch -rt specific code you should have provided a
> > patch against the upstream code in sched-devel/latest.
> >
>
> The cpupri bits have not been added to the sched-devel tree yet. This
> patch involves linking to the cpupri from the rt_root_domain. Thus the
> patch against the latest RT tree. Pl let me know if I understand it
> incorrectly.
The root_domain code is upstream and not -rt specific, that -rt carries
a patch that touches this code is perhaps unfortunate.
We strive to keep the -rt patch as small as possible, that means push
stuff upstream whenever possible. As your patch doesn't change anything
specific to -rt, upstream is the right place to restructure the
root_domain code. Next time the -rt tree gets fwd ported the cpupri bits
will be made to match.