lib/lz4: enable LZ4_FAST_DEC_LOOP on aarch64 Clang builds
Upstream lz4 mentioned a performance regression on Qualcomm SoCs
when built with Clang, but not with GCC [1]. However, according to my
testing on sm8350 with LLVM Clang 15, this patch does offer a nice
10% boost in decompression, so enable the fast dec loop for Clang
as well.
Testing procedure:
- pre-fill zram with 1GB of real-word zram data dumped under memory
pressure, for example
$ dd if=/sdcard/zram.test of=/dev/block/zram0 bs=1m count=1000
- $ fio --readonly --name=randread --direct=1 --rw=randread \
--ioengine=psync --randrepeat=0 --numjobs=4 --iodepth=1 \
--group_reporting=1 --filename=/dev/block/zram0 --bs=4K --size=1000M
Results:
- vanilla lz4: read: IOPS=1646k, BW=6431MiB/s (6743MB/s)(4000MiB/622msec)
- lz4 fast dec: read: IOPS=1775k, BW=6932MiB/s (7269MB/s)(4000MiB/577msec)
[1] https://github.com/lz4/lz4/pull/707
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com>
1 file changed