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author | Alex Waterman <alexw@nvidia.com> | 2017-06-09 14:42:50 -0400 |
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committer | mobile promotions <svcmobile_promotions@nvidia.com> | 2017-07-06 17:44:16 -0400 |
commit | 583704620db88e391f6b14acc57af859a70127de (patch) | |
tree | 8fc3becf2850b724e87011b0e0250c52d0efb7ee /drivers/gpu/nvgpu/perf/perf.h | |
parent | c1393d5b68e63c992f4c689cb788139fdf8c2f1a (diff) |
gpu: nvgpu: Implement PD packing
In some cases page directories require less than a full page of memory.
For example, on Pascal, the final PD level for large pages is only 256 bytes;
thus 16 PDs can fit in a single page. To allocate an entire page for each of
these 256 B PDs is extremely wasteful. This patch aims to alleviate the
wasted DMA memory from having small PDs in a full page by packing multiple
small PDs into a single page.
The packing is implemented as a slab allocator - each page is a slab and
from each page multiple PD instances can be allocated. Several modifications
to the nvgpu_gmmu_pd struct also needed to be made to support this. The
nvgpu_mem is now a pointer and there's an explicit offset into the nvgpu_mem
struct so that each nvgpu_gmmu_pd knows what portion of the memory it's
using.
The nvgpu_pde_phys_addr() function and the pd_write() functions also require
some changes since the PD no longer is always situated at the start of the
nvgpu_mem.
Initialization and cleanup of the page tables for each VM was slightly
modified to work through the new pd_cache implementation. Some PDs (i.e
the PDB), despite not being a full page, still require a full page for
alignment purposes (HW requirements). Thus a direct allocation method for
PDs is still provided. This is also used when a PD that could in principle
be cached is greater than a page in size.
Lastly a new debug flag was added for the pd_cache code.
JIRA NVGPU-30
Change-Id: I64c8037fc356783c1ef203cc143c4d71bbd5d77c
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master/r/1506610
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
GVS: Gerrit_Virtual_Submit
Diffstat (limited to 'drivers/gpu/nvgpu/perf/perf.h')
0 files changed, 0 insertions, 0 deletions