Re: [RFC][PATCH] sched: Rename DIE domain

From: Valentin Schneider <vschneid@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: juri.lelli@redhat.com, peterz@infradead.org,
	dave.hansen@linux.intel.com, bsegall@google.com, hpa@zytor.com,
	agordeev@linux.ibm.com, linux-s390@vger.kernel.org,
	vincent.guittot@linaro.org, x86@kernel.org, mingo@redhat.com,
	mgorman@suse.de, borntraeger@linux.ibm.com, gor@linux.ibm.com,
	hca@linux.ibm.com, npiggin@gmail.com, bp@alien8.de,
	rostedt@goodmis.org, tglx@linutronix.de,
	dietmar.eggemann@arm.com, linuxppc-dev@lists.ozlabs.org,
	linux-kernel@vger.kernel.org, svens@linux.ibm.com,
	bristot@redhat.com
Subject: Re: [RFC][PATCH] sched: Rename DIE domain
Date: Wed, 12 Jul 2023 16:02:38 +0100	[thread overview]
Message-ID: <xhsmh1qhduq9d.mognet@vschneid.remote.csb> (raw)
In-Reply-To: <20230712141056.GI3100107@hirez.programming.kicks-ass.net>

On 12/07/23 16:10, Peter Zijlstra wrote:
> Hi
>
> Thomas just tripped over the x86 topology setup creating a 'DIE' domain
> for the package mask :-)
>
> Since these names are SCHED_DEBUG only, rename them.
> I don't think anybody *should* be relying on this, but who knows.
>

FWIW I don't care much about the actual name.

There are some stray references to DIE in comments - see below. Bit funny
to see:
- *  - Package (DIE)
+ *  - Package (PKG)

With that:
Acked-by: Valentin Schneider <vschneid@redhat.com>

---

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a80a73909dc2a..190a647534984 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9439,7 +9439,7 @@ static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
  * can only do it if @group is an SMT group and has exactly on busy CPU. Larger
  * imbalances in the number of CPUS are dealt with in find_busiest_group().
  *
- * If we are balancing load within an SMT core, or at DIE domain level, always
+ * If we are balancing load within an SMT core, or at PKG domain level, always
  * proceed.
  *
  * Return: true if @env::dst_cpu can do with asym_packing load balance. False
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index e9d9cf776b7ab..2cdcfec1d1c89 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1118,7 +1118,7 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
  *
  *  - Simultaneous multithreading (SMT)
  *  - Multi-Core Cache (MC)
- *  - Package (DIE)
+ *  - Package (PKG)
  *
  * Where the last one more or less denotes everything up to a NUMA node.
  *
@@ -1140,13 +1140,13 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
  *
  * CPU   0   1   2   3   4   5   6   7
  *
- * DIE  [                             ]
+ * PKG  [                             ]
  * MC   [             ] [             ]
  * SMT  [     ] [     ] [     ] [     ]
  *
  *  - or -
  *
- * DIE  0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7
+ * PKG  0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7
  * MC	0-3 0-3 0-3 0-3 4-7 4-7 4-7 4-7
  * SMT  0-1 0-1 2-3 2-3 4-5 4-5 6-7 6-7
  *

