[Intel-gfx] [PATCH] intel: non-blocking mmaps on the cheap
Daniel Vetter
daniel.vetter at ffwll.ch
Wed Sep 21 21:19:29 CEST 2011
This adds a new mode to map gem objects in a non-blocking way.
The new kernel interface required to get the caching level/coherency
is not yet wired up. All the code to transparently choose between gtt
mappings or (if coherent) cpu mappings is already in place, though.
To make this useable for mesa, we need to allow other buffer acces in
between non-blocking modes. It's not a big problem if this accidentaly
blocks once when switching back to non-blocking maps, but domains need
to be correctly tracked.
I've gone through historical kernel versions and luckily the only
place we move a bo from the gtt domain to the cpu domain is in the
set_ioctl. pwrite/pread don't move objects into the cpu domain as long
as they're untiled or llc cached.
So track whether an object is in the gtt domain and invalidate this
only on access to cpu mappings.
Cc: Eric Anholt <eric at anholt.net>
Cc: Ben Widawsky <ben at bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
intel/intel_bufmgr.h | 3 +
intel/intel_bufmgr_gem.c | 156 +++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 142 insertions(+), 17 deletions(-)
diff --git a/intel/intel_bufmgr.h b/intel/intel_bufmgr.h
index 889ef46..47f3416 100644
--- a/intel/intel_bufmgr.h
+++ b/intel/intel_bufmgr.h
@@ -149,6 +149,9 @@ int drm_intel_gem_bo_map_gtt(drm_intel_bo *bo);
int drm_intel_gem_bo_unmap_gtt(drm_intel_bo *bo);
void drm_intel_gem_bo_start_gtt_access(drm_intel_bo *bo, int write_enable);
+int drm_intel_gem_bo_map_nonblocking(drm_intel_bo *bo);
+int drm_intel_gem_bo_unmap_nonblocking(drm_intel_bo *bo);
+
int drm_intel_get_pipe_from_crtc_id(drm_intel_bufmgr *bufmgr, int crtc_id);
int drm_intel_get_aperture_sizes(int fd, size_t *mappable, size_t *total);
diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 4f4de92..ff4b663 100644
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -141,6 +141,8 @@ struct _drm_intel_bo_gem {
uint32_t swizzle_mode;
unsigned long stride;
+ unsigned in_gtt_domain : 1;
+
time_t free_time;
/** Array passed to the DRM containing relocation information. */
@@ -998,15 +1000,11 @@ static void drm_intel_gem_bo_unreference(drm_intel_bo *bo)
}
}
-static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
+static int do_mmap_cpu(drm_intel_bufmgr_gem *bufmgr_gem,
+ drm_intel_bo_gem *bo_gem)
{
- drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
- drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
- struct drm_i915_gem_set_domain set_domain;
int ret;
- pthread_mutex_lock(&bufmgr_gem->lock);
-
/* Allow recursive mapping. Mesa may recursively map buffers with
* nested display loops.
*/
@@ -1018,7 +1016,7 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
memset(&mmap_arg, 0, sizeof(mmap_arg));
mmap_arg.handle = bo_gem->gem_handle;
mmap_arg.offset = 0;
- mmap_arg.size = bo->size;
+ mmap_arg.size = bo_gem->bo.size;
ret = drmIoctl(bufmgr_gem->fd,
DRM_IOCTL_I915_GEM_MMAP,
&mmap_arg);
@@ -1027,11 +1025,27 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
DBG("%s:%d: Error mapping buffer %d (%s): %s .\n",
__FILE__, __LINE__, bo_gem->gem_handle,
bo_gem->name, strerror(errno));
- pthread_mutex_unlock(&bufmgr_gem->lock);
return ret;
}
bo_gem->mem_virtual = (void *)(uintptr_t) mmap_arg.addr_ptr;
}
+ return 0;
+}
+
+static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
+{
+ drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+ drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
+ struct drm_i915_gem_set_domain set_domain;
+ int ret;
+
+ pthread_mutex_lock(&bufmgr_gem->lock);
+
+ ret = do_mmap_cpu(bufmgr_gem, bo_gem);
+ if (ret != 0) {
+ pthread_mutex_unlock(&bufmgr_gem->lock);
+ return ret;
+ }
DBG("bo_map: %d (%s) -> %p\n", bo_gem->gem_handle, bo_gem->name,
bo_gem->mem_virtual);
bo->virtual = bo_gem->mem_virtual;
@@ -1051,20 +1065,19 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
strerror(errno));
}
+ /* TODO ask kernel if llc cached, in that case don't clear this */
+ bo_gem->in_gtt_domain = 0;
+
pthread_mutex_unlock(&bufmgr_gem->lock);
return 0;
}
-int drm_intel_gem_bo_map_gtt(drm_intel_bo *bo)
+static int do_mmap_gtt(drm_intel_bufmgr_gem *bufmgr_gem,
+ drm_intel_bo_gem *bo_gem)
{
- drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
- drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
- struct drm_i915_gem_set_domain set_domain;
int ret;
- pthread_mutex_lock(&bufmgr_gem->lock);
-
/* Get a mapping of the buffer if we haven't before. */
if (bo_gem->gtt_virtual == NULL) {
struct drm_i915_gem_mmap_gtt mmap_arg;
@@ -1085,12 +1098,11 @@ int drm_intel_gem_bo_map_gtt(drm_intel_bo *bo)
__FILE__, __LINE__,
bo_gem->gem_handle, bo_gem->name,
strerror(errno));
- pthread_mutex_unlock(&bufmgr_gem->lock);
return ret;
}
/* and mmap it */
- bo_gem->gtt_virtual = mmap(0, bo->size, PROT_READ | PROT_WRITE,
+ bo_gem->gtt_virtual = mmap(0, bo_gem->bo.size, PROT_READ | PROT_WRITE,
MAP_SHARED, bufmgr_gem->fd,
mmap_arg.offset);
if (bo_gem->gtt_virtual == MAP_FAILED) {
@@ -1100,11 +1112,28 @@ int drm_intel_gem_bo_map_gtt(drm_intel_bo *bo)
__FILE__, __LINE__,
bo_gem->gem_handle, bo_gem->name,
strerror(errno));
- pthread_mutex_unlock(&bufmgr_gem->lock);
return ret;
}
}
+ return 0;
+}
+
+int drm_intel_gem_bo_map_gtt(drm_intel_bo *bo)
+{
+ drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+ drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
+ struct drm_i915_gem_set_domain set_domain;
+ int ret;
+
+ pthread_mutex_lock(&bufmgr_gem->lock);
+
+ ret = do_mmap_gtt(bufmgr_gem, bo_gem);
+ if (ret != 0) {
+ pthread_mutex_unlock(&bufmgr_gem->lock);
+ return ret;
+ }
+
bo->virtual = bo_gem->gtt_virtual;
DBG("bo_map_gtt: %d (%s) -> %p\n", bo_gem->gem_handle, bo_gem->name,
@@ -1123,6 +1152,8 @@ int drm_intel_gem_bo_map_gtt(drm_intel_bo *bo)
strerror(errno));
}
+ bo_gem->in_gtt_domain = 1;
+
pthread_mutex_unlock(&bufmgr_gem->lock);
return 0;
@@ -1282,6 +1313,97 @@ drm_intel_gem_bo_start_gtt_access(drm_intel_bo *bo, int write_enable)
set_domain.read_domains, set_domain.write_domain,
strerror(errno));
}
+
+ bo_gem->in_gtt_domain = 1;
+}
+
+/**
+ * map an object in the non-blocking mode
+ *
+ * This automagically chooses either the gtt mapping or if coherent and faster,
+ * the cpu mapping. Might still blocking under a few conditions (first
+ * non-blocking access on a new buffer object and accessing the buffer throuhg a
+ * blocking cpu map).
+ *
+ * Not allowed on tiled buffers (to prevent headaches with swizzling and
+ * tracking the gem domain).
+ *
+ * Probably not a good idea to share these buffers with flink.
+ */
+int drm_intel_gem_bo_map_nonblocking(drm_intel_bo *bo)
+{
+ drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+ drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
+ struct drm_i915_gem_set_domain set_domain;
+ int gpu_coherent_cpu_map;
+ int ret;
+
+ pthread_mutex_lock(&bufmgr_gem->lock);
+ assert(bo_gem->tiling_mode != I915_TILING_NONE);
+
+ /* TODO ask the kernel about this */
+ gpu_coherent_cpu_map = 1;
+
+ if (gpu_coherent_cpu_map) {
+ ret = do_mmap_cpu(bufmgr_gem, bo_gem);
+ if (ret != 0) {
+ pthread_mutex_unlock(&bufmgr_gem->lock);
+ return ret;
+ }
+
+ bo->virtual = bo_gem->mem_virtual;
+ } else {
+ ret = do_mmap_gtt(bufmgr_gem, bo_gem);
+ if (ret != 0) {
+ pthread_mutex_unlock(&bufmgr_gem->lock);
+ return ret;
+ }
+
+ bo->virtual = bo_gem->gtt_virtual;
+ }
+
+ DBG("bo_map_nonblocking: %d (%s) -> %p\n", bo_gem->gem_handle, bo_gem->name,
+ bo_gem->gtt_virtual);
+
+ /* Move it to the GTT domain in case it isn't there yet */
+ if (!bo_gem->in_gtt_domain) {
+ set_domain.handle = bo_gem->gem_handle;
+ set_domain.read_domains = I915_GEM_DOMAIN_GTT;
+ set_domain.write_domain = I915_GEM_DOMAIN_GTT;
+ ret = drmIoctl(bufmgr_gem->fd,
+ DRM_IOCTL_I915_GEM_SET_DOMAIN,
+ &set_domain);
+ if (ret != 0) {
+ DBG("%s:%d: Error setting domain %d: %s\n",
+ __FILE__, __LINE__, bo_gem->gem_handle,
+ strerror(errno));
+ }
+
+ bo_gem->in_gtt_domain = 1;
+ }
+
+
+ pthread_mutex_unlock(&bufmgr_gem->lock);
+
+ return 0;
+}
+
+/**
+ * unmap an object in the non-blocking mode
+ */
+int drm_intel_gem_bo_unmap_nonblocking(drm_intel_bo *bo)
+{
+ drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+ int ret = 0;
+
+ if (bo == NULL)
+ return 0;
+
+ pthread_mutex_lock(&bufmgr_gem->lock);
+ bo->virtual = NULL;
+ pthread_mutex_unlock(&bufmgr_gem->lock);
+
+ return ret;
}
static void
--
1.7.6.2
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