[RESEND PATCH] sched/topology: Remove unused numa_distance in cpu_attach_domain()

[RESEND PATCH] sched/topology: Remove unused numa_distance in cpu_attach_domain()

[Yicong Yang]

numa_distance in cpu_attach_domain() is introduced in
commit b5b217346de8 ("sched/topology: Warn when NUMA diameter > 2")
to warn user when NUMA diameter > 2 as we'll misrepresent
the scheduler topology structures at that time. This is
fixed by Barry in commit 585b6d2723dc ("sched/topology: fix the issue
groups don't span domain->span for NUMA diameter > 2") and
numa_distance is unused now. So remove it.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
---
 kernel/sched/topology.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 4e8698e62f07..690bd1ab86f3 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -688,7 +688,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
 	struct sched_domain *tmp;
-	int numa_distance = 0;
 
 	/* Remove the sched domains which do not contribute to scheduling. */
 	for (tmp = sd; tmp; ) {
@@ -720,9 +719,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 			sd->child = NULL;
 	}
 
-	for (tmp = sd; tmp; tmp = tmp->parent)
-		numa_distance += !!(tmp->flags & SD_NUMA);
-
 	sched_domain_debug(sd, cpu);
 
 	rq_attach_root(rq, rd);
-- 
2.33.0

Re: [RESEND PATCH] sched/topology: Remove unused numa_distance in cpu_attach_domain()

[Barry Song]

On Wed, Sep 15, 2021 at 9:55 PM Yicong Yang <yangyicong@hisilicon.com> wrote:
>
> numa_distance in cpu_attach_domain() is introduced in
> commit b5b217346de8 ("sched/topology: Warn when NUMA diameter > 2")
> to warn user when NUMA diameter > 2 as we'll misrepresent
> the scheduler topology structures at that time. This is
> fixed by Barry in commit 585b6d2723dc ("sched/topology: fix the issue
> groups don't span domain->span for NUMA diameter > 2") and
> numa_distance is unused now. So remove it.
>
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>

I have double checked this patch and it is quite right.

When I removed the code of WARN_ON(numa_distance > 2), I forgot
to delete the numa_distance which became redundant.

Reviewed-by: Barry Song <baohua@kernel.org>

> ---
>  kernel/sched/topology.c | 4 ----
>  1 file changed, 4 deletions(-)
>
> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> index 4e8698e62f07..690bd1ab86f3 100644
> --- a/kernel/sched/topology.c
> +++ b/kernel/sched/topology.c
> @@ -688,7 +688,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
>  {
>         struct rq *rq = cpu_rq(cpu);
>         struct sched_domain *tmp;
> -       int numa_distance = 0;
>
>         /* Remove the sched domains which do not contribute to scheduling. */
>         for (tmp = sd; tmp; ) {
> @@ -720,9 +719,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
>                         sd->child = NULL;
>         }
>
> -       for (tmp = sd; tmp; tmp = tmp->parent)
> -               numa_distance += !!(tmp->flags & SD_NUMA);
> -
>         sched_domain_debug(sd, cpu);
>
>         rq_attach_root(rq, rd);
> --
> 2.33.0
>

Thanks
barry

Re: [RESEND PATCH] sched/topology: Remove unused numa_distance in cpu_attach_domain()

[Valentin Schneider]

On 15/09/21 14:31, Yicong Yang wrote:
> numa_distance in cpu_attach_domain() is introduced in
> commit b5b217346de8 ("sched/topology: Warn when NUMA diameter > 2")
> to warn user when NUMA diameter > 2 as we'll misrepresent
> the scheduler topology structures at that time. This is
> fixed by Barry in commit 585b6d2723dc ("sched/topology: fix the issue
> groups don't span domain->span for NUMA diameter > 2") and
> numa_distance is unused now. So remove it.
>

Ah, 585b6d2723dc didn't contain a proper revert of b5b217346de8, leaving
those hunks behind.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>

[tip: sched/core] sched/topology: Remove unused numa_distance in cpu_attach_domain()

[tip-bot2 for Yicong Yang]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     f43df9225fcad9b07a4ef4d0fe4c3ad2fb4ce82d
Gitweb:        https://git.kernel.org/tip/f43df9225fcad9b07a4ef4d0fe4c3ad2fb4ce82d
Author:        Yicong Yang <yangyicong@hisilicon.com>
AuthorDate:    Wed, 15 Sep 2021 14:31:58 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 07 Oct 2021 13:51:17 +02:00

sched/topology: Remove unused numa_distance in cpu_attach_domain()

numa_distance in cpu_attach_domain() is introduced in
commit b5b217346de8 ("sched/topology: Warn when NUMA diameter > 2")
to warn user when NUMA diameter > 2 as we'll misrepresent
the scheduler topology structures at that time. This is
fixed by Barry in commit 585b6d2723dc ("sched/topology: fix the issue
groups don't span domain->span for NUMA diameter > 2") and
numa_distance is unused now. So remove it.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lore.kernel.org/r/20210915063158.80639-1-yangyicong@hisilicon.com
---
 kernel/sched/topology.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index c56faae..5af3edd 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -688,7 +688,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
 	struct sched_domain *tmp;
-	int numa_distance = 0;
 
 	/* Remove the sched domains which do not contribute to scheduling. */
 	for (tmp = sd; tmp; ) {
@@ -732,9 +731,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 		}
 	}
 
-	for (tmp = sd; tmp; tmp = tmp->parent)
-		numa_distance += !!(tmp->flags & SD_NUMA);
-
 	sched_domain_debug(sd, cpu);
 
 	rq_attach_root(rq, rd);

[tip: sched/core] sched/topology: Remove unused numa_distance in cpu_attach_domain()

[tip-bot2 for Yicong Yang]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     f9ec6fea201429b5a3f76319e943989f1a1e25ef
Gitweb:        https://git.kernel.org/tip/f9ec6fea201429b5a3f76319e943989f1a1e25ef
Author:        Yicong Yang <yangyicong@hisilicon.com>
AuthorDate:    Wed, 15 Sep 2021 14:31:58 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Thu, 14 Oct 2021 13:09:58 +02:00

sched/topology: Remove unused numa_distance in cpu_attach_domain()

numa_distance in cpu_attach_domain() is introduced in
commit b5b217346de8 ("sched/topology: Warn when NUMA diameter > 2")
to warn user when NUMA diameter > 2 as we'll misrepresent
the scheduler topology structures at that time. This is
fixed by Barry in commit 585b6d2723dc ("sched/topology: fix the issue
groups don't span domain->span for NUMA diameter > 2") and
numa_distance is unused now. So remove it.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lore.kernel.org/r/20210915063158.80639-1-yangyicong@hisilicon.com
---
 kernel/sched/topology.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index c56faae..5af3edd 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -688,7 +688,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
 	struct sched_domain *tmp;
-	int numa_distance = 0;
 
 	/* Remove the sched domains which do not contribute to scheduling. */
 	for (tmp = sd; tmp; ) {
@@ -732,9 +731,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 		}
 	}
 
-	for (tmp = sd; tmp; tmp = tmp->parent)
-		numa_distance += !!(tmp->flags & SD_NUMA);
-
 	sched_domain_debug(sd, cpu);
 
 	rq_attach_root(rq, rd);