[Mesa-dev] [PATCH v2 2/2] anv: Advertise larger heap sizes
Jason Ekstrand
jason at jlekstrand.net
Wed Mar 29 00:41:13 UTC 2017
Instead of just advertising the aperture size, we do something more
intelligent. On systems with a full 48-bit PPGTT, we can address 100%
of the available system RAM from the GPU. In order to keep clients from
burning 100% of your available RAM for graphics resources, we have a
nice little heuristic (which has received exactly zero tuning) to keep
things under a reasonable level of control.
Cc: Alex Smith <asmith at feralinteractive.com>
---
src/intel/vulkan/anv_device.c | 61 +++++++++++++++++++++++++++++++++---------
src/intel/vulkan/anv_gem.c | 16 +++++++++++
src/intel/vulkan/anv_private.h | 13 ++++++++-
3 files changed, 76 insertions(+), 14 deletions(-)
diff --git a/src/intel/vulkan/anv_device.c b/src/intel/vulkan/anv_device.c
index f9d04ee..0e5e4b9 100644
--- a/src/intel/vulkan/anv_device.c
+++ b/src/intel/vulkan/anv_device.c
@@ -25,6 +25,7 @@
#include <stdbool.h>
#include <string.h>
#include <sys/mman.h>
+#include <sys/sysinfo.h>
#include <unistd.h>
#include <fcntl.h>
#include <xf86drm.h>
@@ -53,6 +54,48 @@ compiler_perf_log(void *data, const char *fmt, ...)
va_end(args);
}
+static VkResult
+anv_compute_heap_size(int fd, uint64_t *heap_size)
+{
+ uint64_t gtt_size;
+ if (anv_gem_get_context_param(fd, 0, I915_CONTEXT_PARAM_GTT_SIZE,
+ >t_size) == -1) {
+ /* If, for whatever reason, we can't actually get the GTT size from the
+ * kernel (too old?) fall back to the aperture size.
+ */
+ anv_perf_warn("Failed to get I915_CONTEXT_PARAM_GTT_SIZE: %m");
+
+ if (anv_gem_get_aperture(fd, >t_size) == -1) {
+ return vk_errorf(VK_ERROR_INITIALIZATION_FAILED,
+ "failed to get aperture size: %m");
+ }
+ }
+
+ /* Query the total ram from the system */
+ struct sysinfo info;
+ sysinfo(&info);
+
+ uint64_t total_ram = (uint64_t)info.totalram * (uint64_t)info.mem_unit;
+
+ /* We don't want to burn too much ram with the GPU. If the user has 4GiB
+ * or less, we use at most half. If they have more than 4GiB, we use 3/4.
+ */
+ uint64_t available_ram;
+ if (total_ram <= 4ull * 1024ull * 1024ull * 1024ull)
+ available_ram = total_ram / 2;
+ else
+ available_ram = total_ram * 3 / 4;
+
+ /* We also want to leave some padding for things we allocate in the driver,
+ * so don't go over 3/4 of the GTT either.
+ */
+ uint64_t available_gtt = gtt_size * 3 / 4;
+
+ *heap_size = MIN2(available_ram, available_gtt);
+
+ return VK_SUCCESS;
+}
+
static bool
anv_device_get_cache_uuid(void *uuid)
{
@@ -124,12 +167,6 @@ anv_physical_device_init(struct anv_physical_device *device,
}
}
- if (anv_gem_get_aperture(fd, &device->aperture_size) == -1) {
- result = vk_errorf(VK_ERROR_INITIALIZATION_FAILED,
- "failed to get aperture size: %m");
- goto fail;
- }
-
if (!anv_gem_get_param(fd, I915_PARAM_HAS_WAIT_TIMEOUT)) {
result = vk_errorf(VK_ERROR_INITIALIZATION_FAILED,
"kernel missing gem wait");
@@ -151,6 +188,10 @@ anv_physical_device_init(struct anv_physical_device *device,
device->supports_48bit_addresses = anv_gem_supports_48b_addresses(fd);
+ result = anv_compute_heap_size(fd, &device->heap_size);
+ if (result != VK_SUCCESS)
+ goto fail;
+
if (!anv_device_get_cache_uuid(device->uuid)) {
result = vk_errorf(VK_ERROR_INITIALIZATION_FAILED,
"cannot generate UUID");
@@ -731,12 +772,6 @@ void anv_GetPhysicalDeviceMemoryProperties(
VkPhysicalDeviceMemoryProperties* pMemoryProperties)
{
ANV_FROM_HANDLE(anv_physical_device, physical_device, physicalDevice);
- VkDeviceSize heap_size;
-
- /* Reserve some wiggle room for the driver by exposing only 75% of the
- * aperture to the heap.
- */
- heap_size = 3 * physical_device->aperture_size / 4;
if (physical_device->info.has_llc) {
/* Big core GPUs share LLC with the CPU and thus one memory type can be
@@ -773,7 +808,7 @@ void anv_GetPhysicalDeviceMemoryProperties(
pMemoryProperties->memoryHeapCount = 1;
pMemoryProperties->memoryHeaps[0] = (VkMemoryHeap) {
- .size = heap_size,
+ .size = physical_device->heap_size,
.flags = VK_MEMORY_HEAP_DEVICE_LOCAL_BIT,
};
}
diff --git a/src/intel/vulkan/anv_gem.c b/src/intel/vulkan/anv_gem.c
index 3d45243..5f478b5 100644
--- a/src/intel/vulkan/anv_gem.c
+++ b/src/intel/vulkan/anv_gem.c
@@ -288,6 +288,22 @@ anv_gem_destroy_context(struct anv_device *device, int context)
}
int
+anv_gem_get_context_param(int fd, int context, uint32_t param, uint64_t *value)
+{
+ struct drm_i915_gem_context_param gp = {
+ .ctx_id = context,
+ .param = param,
+ };
+
+ int ret = anv_ioctl(fd, DRM_IOCTL_I915_GEM_CONTEXT_GETPARAM, &gp);
+ if (ret == -1)
+ return -1;
+
+ *value = gp.value;
+ return 0;
+}
+
+int
anv_gem_get_aperture(int fd, uint64_t *size)
{
struct drm_i915_gem_get_aperture aperture = { 0 };
diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index 425e376..0169796 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -543,7 +543,16 @@ struct anv_physical_device {
char path[20];
const char * name;
struct gen_device_info info;
- uint64_t aperture_size;
+ /** Amount of "GPU memory" we want to advertise
+ *
+ * Clearly, this value is bogus since Intel is a UMA architecture. On
+ * gen7 platforms, we are limited by GTT size unless we want to implement
+ * fine-grained tracking and GTT splitting. On Broadwell and above we are
+ * practically unlimited. However, we will never report more than 3/4 of
+ * the total system ram to try and avoid running out of RAM.
+ */
+ uint64_t heap_size;
+ bool supports_48bit_addresses;
struct brw_compiler * compiler;
struct isl_device isl_dev;
int cmd_parser_version;
@@ -675,6 +684,8 @@ int anv_gem_set_tiling(struct anv_device *device, uint32_t gem_handle,
uint32_t stride, uint32_t tiling);
int anv_gem_create_context(struct anv_device *device);
int anv_gem_destroy_context(struct anv_device *device, int context);
+int anv_gem_get_context_param(int fd, int context, uint32_t param,
+ uint64_t *value);
int anv_gem_get_param(int fd, uint32_t param);
bool anv_gem_get_bit6_swizzle(int fd, uint32_t tiling);
int anv_gem_get_aperture(int fd, uint64_t *size);
--
2.5.0.400.gff86faf
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