We are saving first scheduling domain for a cpu in build_sched_domains() by
iterating over the nested sd->child list. We don't actually need to do it this
way.
*per_cpu_ptr(d.sd, i) is guaranteed to be NULL in the beginning as we have
called __visit_domain_allocation_hell() which does a memset to zero for struct
s_data.
So, save pointer to first SD while running the iteration loop over tl's.
Signed-off-by: Viresh Kumar <[email protected]>
---
kernel/sched/core.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 58453b8..638f6cb 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
sd = NULL;
for (tl = sched_domain_topology; tl->init; tl++) {
sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
+ if (!*per_cpu_ptr(d.sd, i))
+ *per_cpu_ptr(d.sd, i) = sd;
if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
sd->flags |= SD_OVERLAP;
if (cpumask_equal(cpu_map, sched_domain_span(sd)))
break;
}
-
- while (sd->child)
- sd = sd->child;
-
- *per_cpu_ptr(d.sd, i) = sd;
}
/* Build the groups for the domains */
--
1.7.12.rc2.18.g61b472e
build_sched_domain() never uses parameter struct s_data *d and so passing it is
useless.
Remove it.
Signed-off-by: Viresh Kumar <[email protected]>
---
kernel/sched/core.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 638f6cb..4210c54 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6490,9 +6490,8 @@ static void __sdt_free(const struct cpumask *cpu_map)
}
struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,
- struct s_data *d, const struct cpumask *cpu_map,
- struct sched_domain_attr *attr, struct sched_domain *child,
- int cpu)
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+ struct sched_domain *child, int cpu)
{
struct sched_domain *sd = tl->init(tl, cpu);
if (!sd)
@@ -6532,7 +6531,7 @@ static int build_sched_domains(const struct cpumask *cpu_map,
sd = NULL;
for (tl = sched_domain_topology; tl->init; tl++) {
- sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
+ sd = build_sched_domain(tl, cpu_map, attr, sd, i);
if (!*per_cpu_ptr(d.sd, i))
*per_cpu_ptr(d.sd, i) = sd;
if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
--
1.7.12.rc2.18.g61b472e
Hi, Viresh
On 06/04/2013 07:20 PM, Viresh Kumar wrote:
[snip]
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 58453b8..638f6cb 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
> sd = NULL;
> for (tl = sched_domain_topology; tl->init; tl++) {
> sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
> + if (!*per_cpu_ptr(d.sd, i))
What about:
if (tl == sched_domain_topology)
It cost less than per_cpu_ptr(), isn't it?
Regards,
Michael Wang
> + *per_cpu_ptr(d.sd, i) = sd;
> if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
> sd->flags |= SD_OVERLAP;
> if (cpumask_equal(cpu_map, sched_domain_span(sd)))
> break;
> }
> -
> - while (sd->child)
> - sd = sd->child;
> -
> - *per_cpu_ptr(d.sd, i) = sd;
> }
>
> /* Build the groups for the domains */
>
On 5 June 2013 10:12, Michael Wang <[email protected]> wrote:
> Hi, Viresh
>
> On 06/04/2013 07:20 PM, Viresh Kumar wrote:
> [snip]
>> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
>> index 58453b8..638f6cb 100644
>> --- a/kernel/sched/core.c
>> +++ b/kernel/sched/core.c
>> @@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
>> sd = NULL;
>> for (tl = sched_domain_topology; tl->init; tl++) {
>> sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
>> + if (!*per_cpu_ptr(d.sd, i))
>
> What about:
> if (tl == sched_domain_topology)
>
> It cost less than per_cpu_ptr(), isn't it?
How can I miss it.. Obviously its better :)
See if below one looks better (Attached too in case gmail screws up
my mail)..
--------x-------------x------------------
From: Viresh Kumar <[email protected]>
Date: Tue, 4 Jun 2013 15:41:15 +0530
Subject: [PATCH] sched: Optimize build_sched_domains() for saving first SD
node for a cpu
We are saving first scheduling domain for a cpu in build_sched_domains() by
iterating over the nested sd->child list. We don't actually need to do it this
way.
tl will be equal to sched_domain_topology for the first iteration and so we can
set *per_cpu_ptr(d.sd, i) based on that. So, save pointer to first SD while
running the iteration loop over tl's.
Signed-off-by: Viresh Kumar <[email protected]>
---
kernel/sched/core.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 58453b8..08a27be 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct
cpumask *cpu_map,
sd = NULL;
for (tl = sched_domain_topology; tl->init; tl++) {
sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
+ if (tl == sched_domain_topology)
+ *per_cpu_ptr(d.sd, i) = sd;
if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
sd->flags |= SD_OVERLAP;
if (cpumask_equal(cpu_map, sched_domain_span(sd)))
break;
}
-
- while (sd->child)
- sd = sd->child;
-
- *per_cpu_ptr(d.sd, i) = sd;
}
/* Build the groups for the domains */
On 06/05/2013 01:07 PM, Viresh Kumar wrote:
> On 5 June 2013 10:12, Michael Wang <[email protected]> wrote:
>> Hi, Viresh
>>
>> On 06/04/2013 07:20 PM, Viresh Kumar wrote:
>> [snip]
>>> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
>>> index 58453b8..638f6cb 100644
>>> --- a/kernel/sched/core.c
>>> +++ b/kernel/sched/core.c
>>> @@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
>>> sd = NULL;
>>> for (tl = sched_domain_topology; tl->init; tl++) {
>>> sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
>>> + if (!*per_cpu_ptr(d.sd, i))
>>
>> What about:
>> if (tl == sched_domain_topology)
>>
>> It cost less than per_cpu_ptr(), isn't it?
>
> How can I miss it.. Obviously its better :)
>
> See if below one looks better (Attached too in case gmail screws up
> my mail)..
Looks good to me :)
Regards,
Michael Wang
>
> --------x-------------x------------------
>
> From: Viresh Kumar <[email protected]>
> Date: Tue, 4 Jun 2013 15:41:15 +0530
> Subject: [PATCH] sched: Optimize build_sched_domains() for saving first SD
> node for a cpu
>
> We are saving first scheduling domain for a cpu in build_sched_domains() by
> iterating over the nested sd->child list. We don't actually need to do it this
> way.
>
> tl will be equal to sched_domain_topology for the first iteration and so we can
> set *per_cpu_ptr(d.sd, i) based on that. So, save pointer to first SD while
> running the iteration loop over tl's.
>
> Signed-off-by: Viresh Kumar <[email protected]>
> ---
> kernel/sched/core.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 58453b8..08a27be 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct
> cpumask *cpu_map,
> sd = NULL;
> for (tl = sched_domain_topology; tl->init; tl++) {
> sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
> + if (tl == sched_domain_topology)
> + *per_cpu_ptr(d.sd, i) = sd;
> if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
> sd->flags |= SD_OVERLAP;
> if (cpumask_equal(cpu_map, sched_domain_span(sd)))
> break;
> }
> -
> - while (sd->child)
> - sd = sd->child;
> -
> - *per_cpu_ptr(d.sd, i) = sd;
> }
>
> /* Build the groups for the domains */
>
On Wed, Jun 05, 2013 at 10:37:29AM +0530, Viresh Kumar wrote:
> On 5 June 2013 10:12, Michael Wang <[email protected]> wrote:
> > Hi, Viresh
> >
> > On 06/04/2013 07:20 PM, Viresh Kumar wrote:
> > [snip]
> >> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> >> index 58453b8..638f6cb 100644
> >> --- a/kernel/sched/core.c
> >> +++ b/kernel/sched/core.c
> >> @@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
> >> sd = NULL;
> >> for (tl = sched_domain_topology; tl->init; tl++) {
> >> sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
> >> + if (!*per_cpu_ptr(d.sd, i))
> >
> > What about:
> > if (tl == sched_domain_topology)
> >
> > It cost less than per_cpu_ptr(), isn't it?
>
> How can I miss it.. Obviously its better :)
>
> See if below one looks better (Attached too in case gmail screws up
> my mail)..
>
> --------x-------------x------------------
>
> From: Viresh Kumar <[email protected]>
> Date: Tue, 4 Jun 2013 15:41:15 +0530
> Subject: [PATCH] sched: Optimize build_sched_domains() for saving first SD
> node for a cpu
>
> We are saving first scheduling domain for a cpu in build_sched_domains() by
> iterating over the nested sd->child list. We don't actually need to do it this
> way.
>
> tl will be equal to sched_domain_topology for the first iteration and so we can
> set *per_cpu_ptr(d.sd, i) based on that. So, save pointer to first SD while
> running the iteration loop over tl's.
>
> Signed-off-by: Viresh Kumar <[email protected]>
> ---
> kernel/sched/core.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 58453b8..08a27be 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct
> cpumask *cpu_map,
Applying patch
patches/viresh_kumar-_patch__sched-optimize_build_sched_domains_for_saving_first_sd.patch
patching file kernel/sched/core.c
patch: **** malformed patch at line 56: cpumask *cpu_map,
On 5 June 2013 16:34, Peter Zijlstra <[email protected]> wrote:
> On Wed, Jun 05, 2013 at 10:37:29AM +0530, Viresh Kumar wrote:
>> See if below one looks better (Attached too in case gmail screws up
>> my mail)..
> Applying patch
> patches/viresh_kumar-_patch__sched-optimize_build_sched_domains_for_saving_first_sd.patch
> patching file kernel/sched/core.c
> patch: **** malformed patch at line 56: cpumask *cpu_map,
You tried to apply patch from mail or attachment? I requested to
pick attachment as gmail's copy-paste screws up patches.
I rebased it over tip/master now:
2bf6874 Merge branch 'x86/cleanups'
Patches are attached now.
On Wed, Jun 05, 2013 at 06:12:15PM +0530, Viresh Kumar wrote:
> On 5 June 2013 16:34, Peter Zijlstra <[email protected]> wrote:
> > On Wed, Jun 05, 2013 at 10:37:29AM +0530, Viresh Kumar wrote:
>
> >> See if below one looks better (Attached too in case gmail screws up
> >> my mail)..
>
> > Applying patch
> > patches/viresh_kumar-_patch__sched-optimize_build_sched_domains_for_saving_first_sd.patch
> > patching file kernel/sched/core.c
> > patch: **** malformed patch at line 56: cpumask *cpu_map,
>
> You tried to apply patch from mail or attachment? I requested to
> pick attachment as gmail's copy-paste screws up patches.
>
>From email; that's what my mailer is scripted for. TBH I didn't even
notice the attachment.
I'll go prod at the attachment.