On Wed, Dec 09, 2015 at 10:00:02AM +0000, Shachar Raindel wrote: > > Yes please.
> Note that other HW vendors are developing similar solutions, see for > example: > http://www.slideshare.net/linaroorg/hkg15106-replacing-cmem-meeting-tis-soc-shared-buffer-allocation-management-and-address-translation-requirements CMA and it's successors are for something totally different. > > We already have huge page mmaps, how much win is had by going from > > huge page maps to this contiguous map? > > As far as gain is concerned, we are seeing gains in two cases here: > 1. If the system has lots of non-fragmented, free memory, you can > create large contig blocks that are above the CPU huge page size. > 2. If the system memory is very fragmented, you cannot allocate huge > pages. However, an API that allows you to create small (i.e. 64KB, > 128KB, etc.) contig blocks reduces the load on the HW page tables > and caches. I understand what it does, I was looking for performance numbers. The last time I trivially benchmarked huge pages vs not huge pages on mlx4 I wasn't able to detect a performance difference. Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
