[PATCH] drm/amdgpu: Use free system memory size for kfd memory accounting

[Oak Zeng]

With the current kfd memory accounting scheme, kfd applications
can use up to 15/16 of total system memory. For system which
has small total system memory size it leaves small system memory
for OS. For example, if the system has totally 16GB of system
memory, this scheme leave OS and non-kfd applications only 1GB
of system memory. In many cases, this leads to OOM killer.

This patch changed the KFD system memory accounting scheme.
15/16 of free system memory when kfd driver load. This deduct
the system memory that OS already use.

Signed-off-by: Oak Zeng <Oak.Zeng at amd.com>
Suggested-by: Philip Yang <Philip.Yang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c       | 2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
index b147d75..e059367 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
@@ -45,7 +45,7 @@ int amdgpu_amdkfd_init(void)
 	int ret;
 
 	si_meminfo(&si);
-	amdgpu_amdkfd_total_mem_size = si.totalram - si.totalhigh;
+	amdgpu_amdkfd_total_mem_size = si.freeram - si.freehigh;
 	amdgpu_amdkfd_total_mem_size *= si.mem_unit;
 
 #ifdef CONFIG_HSA_AMD
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 58c8739..44d362b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -97,7 +97,7 @@ void amdgpu_amdkfd_gpuvm_init_mem_limits(void)
 	uint64_t mem;
 
 	si_meminfo(&si);
-	mem = si.totalram - si.totalhigh;
+	mem = si.freeram - si.freehigh;
 	mem *= si.mem_unit;
 
 	spin_lock_init(&kfd_mem_limit.mem_limit_lock);
-- 
2.7.4