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 viresh.kumar@linaro.org --- 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 */
build_sched_domain() never uses parameter struct s_data *d and so passing it is useless.
Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- 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))
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 wangyun@linux.vnet.ibm.com 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 viresh.kumar@linaro.org 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 viresh.kumar@linaro.org --- 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 wangyun@linux.vnet.ibm.com 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 viresh.kumar@linaro.org 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 viresh.kumar@linaro.org
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 wangyun@linux.vnet.ibm.com 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 viresh.kumar@linaro.org 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 viresh.kumar@linaro.org
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 peterz@infradead.org 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 peterz@infradead.org 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.
linaro-kernel@lists.linaro.org
-
Michael Wang -
Peter Zijlstra -
Viresh Kumar