On 2022-08-12 09:55, Philip Yang wrote:
On 2022-08-11 15:04, Felix Kuehling wrote:
On systems that support SMT (hyperthreading) schedule the bottom half of
the KFD interrupt handler on the same core. This makes it possible to
reserve a core for interrupt handling and have the bottom half run on
that same core.
On systems without SMT, pick another core in the same NUMA node, as
before.
Use for_each_cpu_wrap instead of open-coding it.
Signed-off-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
nit-pick below, looks better to use new_cpu as iterator, either way
this is
Reviewed-by: Philip Yang <Philip.Yang@xxxxxxx>
Thank you. I think I prefer cpu as the iterator and new_cpu as the
variable that holds the CPU we choose to schedule to.
Regards,
Felix
---
drivers/gpu/drm/amd/amdkfd/kfd_device.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
index f5853835f03a..4d1284714e7a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
@@ -24,6 +24,7 @@
#include <linux/bsearch.h>
#include <linux/pci.h>
#include <linux/slab.h>
+#include <linux/topology.h>
#include "kfd_priv.h"
#include "kfd_device_queue_manager.h"
#include "kfd_pm4_headers_vi.h"
@@ -801,13 +802,24 @@ static inline void kfd_queue_work(struct
workqueue_struct *wq,
struct work_struct *work)
{
int cpu, new_cpu;
+ const struct cpumask *mask = NULL;
cpu = new_cpu = smp_processor_id();
- do {
- new_cpu = cpumask_next(new_cpu, cpu_online_mask) % nr_cpu_ids;
- if (cpu_to_node(new_cpu) == numa_node_id())
+
+#if defined(CONFIG_SCHED_SMT)
+ /* CPU threads in the same core */
+ mask = cpu_smt_mask(cpu);
+#endif
+ if (!mask || cpumask_weight(mask) <= 1)
+ /* CPU threads in the same NUMA node */
+ mask = cpu_cpu_mask(cpu);
+ /* Pick the next online CPU thread in the same core or NUMA node */
+ for_each_cpu_wrap(cpu, mask, cpu+1) {
+ if (cpu != new_cpu && cpu_online(cpu)) {
+ new_cpu = cpu;
break;
- } while (cpu != new_cpu);
+ }
+ }
queue_work_on(new_cpu, wq, work);
}
for_each_cpu_wrap(new_cpu, mask, cpu + 1) {
if (cpu != new_cpu && cpu_online(new_cpu)) {
cpu = new_cpu;
break;
}
}
queue_work_on(cpu, wq, work);
