From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/block/blk-mq-cpumap.c | 51 ++++++++++++++++++++++++++++++++++++---------------
1 files changed, 36 insertions(+), 15 deletions(-)
diff --git a/kernel/block/blk-mq-cpumap.c b/kernel/block/blk-mq-cpumap.c
index 3eb169f..3db84d3 100644
--- a/kernel/block/blk-mq-cpumap.c
+++ b/kernel/block/blk-mq-cpumap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* CPU <-> hardware queue mapping helpers
*
@@ -14,9 +15,10 @@
#include "blk.h"
#include "blk-mq.h"
-static int cpu_to_queue_index(unsigned int nr_queues, const int cpu)
+static int queue_index(struct blk_mq_queue_map *qmap,
+ unsigned int nr_queues, const int q)
{
- return cpu % nr_queues;
+ return qmap->queue_offset + (q % nr_queues);
}
static int get_first_sibling(unsigned int cpu)
@@ -30,25 +32,40 @@
return cpu;
}
-int blk_mq_map_queues(struct blk_mq_tag_set *set)
+int blk_mq_map_queues(struct blk_mq_queue_map *qmap)
{
- unsigned int *map = set->mq_map;
- unsigned int nr_queues = set->nr_hw_queues;
- unsigned int cpu, first_sibling;
+ unsigned int *map = qmap->mq_map;
+ unsigned int nr_queues = qmap->nr_queues;
+ unsigned int cpu, first_sibling, q = 0;
+
+ for_each_possible_cpu(cpu)
+ map[cpu] = -1;
+
+ /*
+ * Spread queues among present CPUs first for minimizing
+ * count of dead queues which are mapped by all un-present CPUs
+ */
+ for_each_present_cpu(cpu) {
+ if (q >= nr_queues)
+ break;
+ map[cpu] = queue_index(qmap, nr_queues, q++);
+ }
for_each_possible_cpu(cpu) {
+ if (map[cpu] != -1)
+ continue;
/*
* First do sequential mapping between CPUs and queues.
* In case we still have CPUs to map, and we have some number of
- * threads per cores then map sibling threads to the same queue for
- * performace optimizations.
+ * threads per cores then map sibling threads to the same queue
+ * for performance optimizations.
*/
- if (cpu < nr_queues) {
- map[cpu] = cpu_to_queue_index(nr_queues, cpu);
+ if (q < nr_queues) {
+ map[cpu] = queue_index(qmap, nr_queues, q++);
} else {
first_sibling = get_first_sibling(cpu);
if (first_sibling == cpu)
- map[cpu] = cpu_to_queue_index(nr_queues, cpu);
+ map[cpu] = queue_index(qmap, nr_queues, q++);
else
map[cpu] = map[first_sibling];
}
@@ -58,17 +75,21 @@
}
EXPORT_SYMBOL_GPL(blk_mq_map_queues);
-/*
+/**
+ * blk_mq_hw_queue_to_node - Look up the memory node for a hardware queue index
+ * @qmap: CPU to hardware queue map.
+ * @index: hardware queue index.
+ *
* We have no quick way of doing reverse lookups. This is only used at
* queue init time, so runtime isn't important.
*/
-int blk_mq_hw_queue_to_node(unsigned int *mq_map, unsigned int index)
+int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index)
{
int i;
for_each_possible_cpu(i) {
- if (index == mq_map[i])
- return local_memory_node(cpu_to_node(i));
+ if (index == qmap->mq_map[i])
+ return cpu_to_node(i);
}
return NUMA_NO_NODE;
--
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