On Wed, Aug 12, 2020 at 02:17:11PM +0900, Daeho Jeong wrote: > From: Daeho Jeong <daehoje...@google.com> > > By profiling f2fs compression works, I've found vmap() callings have > unexpected hikes in the execution time in our test environment and > those are bottlenecks of f2fs decompression path. Changing these with > vm_map_ram(), we can enhance f2fs decompression speed pretty much. > > [Verification] > Android Pixel 3(ARM64, 6GB RAM, 128GB UFS) > Turned on only 0-3 little cores(at 1.785GHz) > > dd if=/dev/zero of=dummy bs=1m count=1000 > echo 3 > /proc/sys/vm/drop_caches > dd if=dummy of=/dev/zero bs=512k > > - w/o compression - > 1048576000 bytes (0.9 G) copied, 2.082554 s, 480 M/s > 1048576000 bytes (0.9 G) copied, 2.081634 s, 480 M/s > 1048576000 bytes (0.9 G) copied, 2.090861 s, 478 M/s > > - before patch - > 1048576000 bytes (0.9 G) copied, 7.407527 s, 135 M/s > 1048576000 bytes (0.9 G) copied, 7.283734 s, 137 M/s > 1048576000 bytes (0.9 G) copied, 7.291508 s, 137 M/s > > - after patch - > 1048576000 bytes (0.9 G) copied, 1.998959 s, 500 M/s > 1048576000 bytes (0.9 G) copied, 1.987554 s, 503 M/s > 1048576000 bytes (0.9 G) copied, 1.986380 s, 503 M/s >
The reason why I raised up this was that I once observed vmap() vs vm_map_ram() on arm64 kirin platform as well. it indeed had some impact (~10%) but not as huge as this. Anyway, such description with test environment looks ok. Thanks, Gao Xiang _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
