From: Amber Lin Date: Fri, 15 Aug 2025 18:04:15 +0000 (-0400) Subject: drm/amdkfd: Tie UNMAP_LATENCY to queue_preemption X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f3820e9d356132e18405cd7606e22dc87ccfa6d1;p=users%2Fhch%2Fmisc.git drm/amdkfd: Tie UNMAP_LATENCY to queue_preemption When KFD asks CP to preempt queues, other than preempt CP queues, CP also requests SDMA to preempt SDMA queues with UNMAP_LATENCY timeout. Currently queue_preemption_timeout_ms is 9000 ms by default but can be configured via module parameter. KFD_UNMAP_LATENCY_MS is hard coded as 4000 ms though. This patch ties KFD_UNMAP_LATENCY_MS to queue_preemption_timeout_ms so in a slow system such as emulator, both CP and SDMA slowness are taken into account. Signed-off-by: Amber Lin Reviewed-by: Harish Kasiviswanathan Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h index 67694bcd9464..d01ef5ac0766 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h @@ -111,7 +111,14 @@ #define KFD_KERNEL_QUEUE_SIZE 2048 -#define KFD_UNMAP_LATENCY_MS (4000) +/* KFD_UNMAP_LATENCY_MS is the timeout CP waiting for SDMA preemption. One XCC + * can be associated to 2 SDMA engines. queue_preemption_timeout_ms is the time + * driver waiting for CP returning the UNMAP_QUEUE fence. Thus the math is + * queue_preemption_timeout_ms = sdma_preemption_time * 2 + cp workload + * The format here makes CP workload 10% of total timeout + */ +#define KFD_UNMAP_LATENCY_MS \ + ((queue_preemption_timeout_ms - queue_preemption_timeout_ms / 10) >> 1) #define KFD_MAX_SDMA_QUEUES 128