diff mbox series

[v3,14/15] lib/group_cpus.c: honor housekeeping config when grouping CPUs

Message ID 20240806-isolcpus-io-queues-v3-14-da0eecfeaf8b@suse.de
State New
Headers show
Series honor isolcpus configuration | expand

Commit Message

Daniel Wagner Aug. 6, 2024, 12:06 p.m. UTC
group_cpus_evenly distributes all present CPUs into groups. This ignores
the isolcpus configuration and assigns isolated CPUs into the groups.

Make group_cpus_evenly aware of isolcpus configuration and use the
housekeeping CPU mask as base for distributing the available CPUs into
groups.

Fixes: 11ea68f553e2 ("genirq, sched/isolation: Isolate from handling managed interrupts")
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 lib/group_cpus.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 73 insertions(+), 2 deletions(-)

Comments

Ming Lei Aug. 6, 2024, 2:47 p.m. UTC | #1
On Tue, Aug 06, 2024 at 02:06:46PM +0200, Daniel Wagner wrote:
> group_cpus_evenly distributes all present CPUs into groups. This ignores
> the isolcpus configuration and assigns isolated CPUs into the groups.
> 
> Make group_cpus_evenly aware of isolcpus configuration and use the
> housekeeping CPU mask as base for distributing the available CPUs into
> groups.
> 
> Fixes: 11ea68f553e2 ("genirq, sched/isolation: Isolate from handling managed interrupts")

This patch fixes nothing on commit 11ea68f553e2, please remove the above
Fixes tag.


Thanks,
Ming
Christoph Hellwig Aug. 12, 2024, 9:09 a.m. UTC | #2
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/lib/group_cpus.c b/lib/group_cpus.c
index ee272c4cefcc..713c9fdd774a 100644
--- a/lib/group_cpus.c
+++ b/lib/group_cpus.c
@@ -8,6 +8,7 @@ 
 #include <linux/cpu.h>
 #include <linux/sort.h>
 #include <linux/group_cpus.h>
+#include <linux/sched/isolation.h>
 
 #ifdef CONFIG_SMP
 
@@ -330,7 +331,7 @@  static int __group_cpus_evenly(unsigned int startgrp, unsigned int numgrps,
 }
 
 /**
- * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
+ * group_possible_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
  * @numgrps: number of groups
  *
  * Return: cpumask array if successful, NULL otherwise. And each element
@@ -344,7 +345,7 @@  static int __group_cpus_evenly(unsigned int startgrp, unsigned int numgrps,
  * We guarantee in the resulted grouping that all CPUs are covered, and
  * no same CPU is assigned to multiple groups
  */
-struct cpumask *group_cpus_evenly(unsigned int numgrps)
+static struct cpumask *group_possible_cpus_evenly(unsigned int numgrps)
 {
 	unsigned int curgrp = 0, nr_present = 0, nr_others = 0;
 	cpumask_var_t *node_to_cpumask;
@@ -423,6 +424,76 @@  struct cpumask *group_cpus_evenly(unsigned int numgrps)
 	}
 	return masks;
 }
+
+/**
+ * group_mask_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
+ * @numgrps: number of groups
+ * @cpu_mask: CPU to consider for the grouping
+ *
+ * Return: cpumask array if successful, NULL otherwise. And each element
+ * includes CPUs assigned to this group.
+ *
+ * Try to put close CPUs from viewpoint of CPU and NUMA locality into
+ * same group. Allocate present CPUs on these groups evenly.
+ */
+static struct cpumask *group_mask_cpus_evenly(unsigned int numgrps,
+					      const struct cpumask *cpu_mask)
+{
+	cpumask_var_t *node_to_cpumask;
+	cpumask_var_t nmsk;
+	int ret = -ENOMEM;
+	struct cpumask *masks = NULL;
+
+	if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
+		return NULL;
+
+	node_to_cpumask = alloc_node_to_cpumask();
+	if (!node_to_cpumask)
+		goto fail_nmsk;
+
+	masks = kcalloc(numgrps, sizeof(*masks), GFP_KERNEL);
+	if (!masks)
+		goto fail_node_to_cpumask;
+
+	build_node_to_cpumask(node_to_cpumask);
+
+	ret = __group_cpus_evenly(0, numgrps, node_to_cpumask, cpu_mask, nmsk,
+				  masks);
+
+fail_node_to_cpumask:
+	free_node_to_cpumask(node_to_cpumask);
+
+fail_nmsk:
+	free_cpumask_var(nmsk);
+	if (ret < 0) {
+		kfree(masks);
+		return NULL;
+	}
+	return masks;
+}
+
+/**
+ * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality
+ * @numgrps: number of groups
+ *
+ * Return: cpumask array if successful, NULL otherwise.
+ *
+ * group_possible_cpus_evently() is used for distributing the cpus on all
+ * possible cpus in absence of isolcpus command line argument.
+ * group_mask_cpu_evenly() is used when the isolcpus command line
+ * argument is used with managed_irq option. In this case only the
+ * housekeeping CPUs are considered.
+ */
+struct cpumask *group_cpus_evenly(unsigned int numgrps)
+{
+	const struct cpumask *hk_mask;
+
+	hk_mask = housekeeping_cpumask(HK_TYPE_IO_QUEUE);
+	if (!cpumask_empty(hk_mask))
+		return group_mask_cpus_evenly(numgrps, hk_mask);
+
+	return group_possible_cpus_evenly(numgrps);
+}
 #else /* CONFIG_SMP */
 struct cpumask *group_cpus_evenly(unsigned int numgrps)
 {