drm/amdkfd: option to disable system mem limit

If multiple process share system memory through /dev/shm, KFD allocate
memory should not fail if it reaches the system memory limit because
one copy of physical system memory are shared by multiple process.

Add module parameter no_system_mem_limit to provide user option to
disable system memory limit check at runtime using sysfs or during
driver module init using kernel boot argument. By default the system
memory limit is on.

Print out debug message to warn user if KFD allocate memory failed
because system memory reaches limit.

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index a5ea70697fba916fe16bc6097faaf12bc92a0e52..3e82a11577d90de447bc98dd72db891542fa97cb 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -188,9 +188,11 @@ extern int amdgpu_force_asic_type;
 #ifdef CONFIG_HSA_AMD
 extern int sched_policy;
 extern bool debug_evictions;
+extern bool no_system_mem_limit;
 #else
 static const int sched_policy = KFD_SCHED_POLICY_HWS;
 static const bool debug_evictions; /* = false */
+static const bool no_system_mem_limit;
 #endif
 
 extern int amdgpu_tmz;

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index a21cf84b882c071a870e15e8bbc88711e561e6b1..fcf72f3377852e92d2a8332c695877e90fe555c4 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -148,8 +148,12 @@ static int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev,
 
        spin_lock(&kfd_mem_limit.mem_limit_lock);
 
+       if (kfd_mem_limit.system_mem_used + system_mem_needed >
+           kfd_mem_limit.max_system_mem_limit)
+               pr_debug("Set no_system_mem_limit=1 if using shared memory\n");
+
        if ((kfd_mem_limit.system_mem_used + system_mem_needed >
-            kfd_mem_limit.max_system_mem_limit) ||
+            kfd_mem_limit.max_system_mem_limit && !no_system_mem_limit) ||
            (kfd_mem_limit.ttm_mem_used + ttm_mem_needed >
             kfd_mem_limit.max_ttm_mem_limit) ||
            (adev->kfd.vram_used + vram_needed >

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 6d66705a114136e9ebe1ea73af75187e2d586d7c..5156c67ec67b71b10b793adafd34b856bcb9f159 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -717,6 +717,15 @@ MODULE_PARM_DESC(queue_preemption_timeout_ms, "queue preemption timeout in ms (1
 bool debug_evictions;
 module_param(debug_evictions, bool, 0644);
 MODULE_PARM_DESC(debug_evictions, "enable eviction debug messages (false = default)");
+
+/**
+ * DOC: no_system_mem_limit(bool)
+ * Disable system memory limit, to support multiple process shared memory
+ */
+bool no_system_mem_limit;
+module_param(no_system_mem_limit, bool, 0644);
+MODULE_PARM_DESC(no_system_mem_limit, "disable system memory limit (false = default)");
+
 #endif
 
 /**