Media userspace was the last userspace to still use them, and they converted now too:
https://github.com/intel/media-driver/commit/144020c37770083974bedf59902b70b...
This means no reason anymore to make relocations faster than they've been for the first 9 years of gem. This code was added in
commit 7dd4f6729f9243bd7046c6f04c107a456bda38eb Author: Chris Wilson chris@chris-wilson.co.uk Date: Fri Jun 16 15:05:24 2017 +0100
drm/i915: Async GPU relocation processing
Furthermore there's pretty strong indications it's buggy, since the code to use it by default as the only option had to be reverted:
commit ad5d95e4d538737ed3fa25493777decf264a3011 Author: Dave Airlie airlied@redhat.com Date: Tue Sep 8 15:41:17 2020 +1000
Revert "drm/i915/gem: Async GPU relocations only"
This code just disables gpu relocations, leaving the garbage collection for later patches and more importantly, much less confusing diff. Also given how much headaches this code has caused in the past, letting this soak for a bit seems justified.
Cc: Jon Bloomfield jon.bloomfield@intel.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: "Thomas Hellström" thomas.hellstrom@linux.intel.com Cc: Matthew Auld matthew.auld@intel.com Cc: Lionel Landwerlin lionel.g.landwerlin@intel.com Cc: Dave Airlie airlied@redhat.com Cc: Jason Ekstrand jason@jlekstrand.net --- .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 43 ++++++++----------- 1 file changed, 18 insertions(+), 25 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index 297143511f99..31e904f79d0a 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -1571,7 +1571,7 @@ static int __reloc_entry_gpu(struct i915_execbuffer *eb, return true; }
-static int reloc_entry_gpu(struct i915_execbuffer *eb, +static int __maybe_unused reloc_entry_gpu(struct i915_execbuffer *eb, struct i915_vma *vma, u64 offset, u64 target_addr) @@ -1593,32 +1593,25 @@ relocate_entry(struct i915_vma *vma, { u64 target_addr = relocation_target(reloc, target); u64 offset = reloc->offset; - int reloc_gpu = reloc_entry_gpu(eb, vma, offset, target_addr); - - if (reloc_gpu < 0) - return reloc_gpu; - - if (!reloc_gpu) { - bool wide = eb->reloc_cache.use_64bit_reloc; - void *vaddr; + bool wide = eb->reloc_cache.use_64bit_reloc; + void *vaddr;
repeat: - vaddr = reloc_vaddr(vma->obj, eb, - offset >> PAGE_SHIFT); - if (IS_ERR(vaddr)) - return PTR_ERR(vaddr); - - GEM_BUG_ON(!IS_ALIGNED(offset, sizeof(u32))); - clflush_write32(vaddr + offset_in_page(offset), - lower_32_bits(target_addr), - eb->reloc_cache.vaddr); - - if (wide) { - offset += sizeof(u32); - target_addr >>= 32; - wide = false; - goto repeat; - } + vaddr = reloc_vaddr(vma->obj, eb, + offset >> PAGE_SHIFT); + if (IS_ERR(vaddr)) + return PTR_ERR(vaddr); + + GEM_BUG_ON(!IS_ALIGNED(offset, sizeof(u32))); + clflush_write32(vaddr + offset_in_page(offset), + lower_32_bits(target_addr), + eb->reloc_cache.vaddr); + + if (wide) { + offset += sizeof(u32); + target_addr >>= 32; + wide = false; + goto repeat; }
return target->node.start | UPDATE;