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Nick Terrell
b1a3e75e46
This patch replaces all memcpy() calls with LZ4_memcpy() which calls __builtin_memcpy() so the compiler can inline it. LZ4 relies heavily on memcpy() with a constant size being inlined. In x86 and i386 pre-boot environments memcpy() cannot be inlined because memcpy() doesn't get defined as __builtin_memcpy(). An equivalent patch has been applied upstream so that the next import won't lose this change [1]. I've measured the kernel decompression speed using QEMU before and after this patch for the x86_64 and i386 architectures. The speed-up is about 10x as shown below. Code Arch Kernel Size Time Speed v5.8 x86_64 11504832 B 148 ms 79 MB/s patch x86_64 11503872 B 13 ms 885 MB/s v5.8 i386 9621216 B 91 ms 106 MB/s patch i386 9620224 B 10 ms 962 MB/s I also measured the time to decompress the initramfs on x86_64, i386, and arm. All three show the same decompression speed before and after, as expected. [1] https://github.com/lz4/lz4/pull/890 Signed-off-by: Nick Terrell <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Yann Collet <[email protected]> Cc: Gao Xiang <[email protected]> Cc: Sven Schmidt <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Arvind Sankar <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>