diff options
author | Ashish Mhetre <amhetre@nvidia.com> | 2024-08-06 10:51:35 +0000 |
---|---|---|
committer | Joerg Roedel <jroedel@suse.de> | 2024-08-30 14:29:32 +0200 |
commit | 84b2baf427968c1b2e3ae3b7afcb0118cdee0915 (patch) | |
tree | e85ebaec3fbbd28f607faa07aaffbb2ab69c12f7 /fs | |
parent | 6c17c7d5936e6af6a5bda9f9de98a5e2ee6e8a6f (diff) |
iommu/io-pgtable-arm: Optimise non-coherent unmap
The current __arm_lpae_unmap() function calls dma_sync() on individual
PTEs after clearing them. Overall unmap performance can be improved by
around 25% for large buffer sizes by combining the syncs for adjacent
leaf entries.
Optimize the unmap time by clearing all the leaf entries and issuing a
single dma_sync() for them.
Below is detailed analysis of average unmap latency(in us) with and
without this optimization obtained by running dma_map_benchmark for
different buffer sizes.
UnMap Latency(us)
Size Without With % gain with
optimiztion optimization optimization
4KB 3 3 0
8KB 4 3.8 5
16KB 6.1 5.4 11.48
32KB 10.2 8.5 16.67
64KB 18.5 14.9 19.46
128KB 35 27.5 21.43
256KB 67.5 52.2 22.67
512KB 127.9 97.2 24.00
1MB 248.6 187.4 24.62
2MB 65.5 65.5 0
4MB 119.2 119 0.17
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Ashish Mhetre <amhetre@nvidia.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240806105135.218089-1-amhetre@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'fs')
0 files changed, 0 insertions, 0 deletions