On 2018-11-30 15:26, Dave Rodgman wrote: > This patch series introduces performance improvements for lzo. > > The previous version of this patchset is here: > https://lkml.org/lkml/2018/11/30/807 > > This version of the patchset fixes a maybe-used-uninitialized warning > (although the previous version was still safe). > > Dave
Hi Dave, as indicated in my previous mail please split your series into three distinct pull requests. Request 1 - ARM64 improvements; acked by me [PATCH 1/8] lib/lzo: tidy-up ifdefs [PATCH 3/8] lib/lzo: enable 64-bit CTZ on Arm [PATCH 4/8] lib/lzo: 64-bit CTZ on arm64 [PATCH 5/8] lib/lzo: fast 8-byte copy on arm64 are simple arch patches that give a nice speedup on ARM64 and should get merged ASAP. Request 2 - add COPY16; *NOT* acked by me [PATCH 2/8] lib/lzo: clean-up by introducing COPY16 is still not correct because of possible overlapping copies. I'll address this on the weekend. Request 3 - add lzo-rle; *NOT* acked by me [PATCH 6/8] lib/lzo: implement run-length encoding [PATCH 7/8] lib/lzo: separate lzo-rle from lzo [PATCH 8/8] zram: default to lzo-rle instead of lzo This can *NOT* be applied in the current implementation. It (1) silently changes the compressed data format, (2) crashes on MIPS, and (3) makes compression and decompression on typical data 10% slower on X86_64 with our internal benchmarks, and (4) has to be carefully checked for buffer overflows. I understand that we want some optimizations for data with many zeros like in the typical ZRAM use case, but the implementation will clearly need some more work. I'll also have a look at the weekend - eg I have a nice idea how to deal with (1). As a final comment, I question the quality your benchmarks - combining arch-related ARM64 improvements and algorithmic changes into one benchmark comparision is just unprofessional marketing. Cheers, Markus -- Markus Oberhumer, <[email protected]>, http://www.oberhumer.com/
