The patch titled Subject: lib/lzo: 64-bit CTZ on arm64 has been added to the -mm tree. Its filename is lib-lzo-64-bit-ctz-on-arm64.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/lib-lzo-64-bit-ctz-on-arm64.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/lib-lzo-64-bit-ctz-on-arm64.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Matt Sealey <matt.sealey@xxxxxxx> Subject: lib/lzo: 64-bit CTZ on arm64 LZO leaves some performance on the table by not realising that arm64 can optimize count-trailing-zeros bit operations. Add CONFIG_ARM64 to the checked definitions alongside CONFIG_X86_64 to enable the use of rbit/clz instructions on full 64-bit quantities. Link: http://lkml.kernel.org/r/20181127161913.23863-5-dave.rodgman@xxxxxxx Link: http://lkml.kernel.org/r/20190205141950.9058-3-dave.rodgman@xxxxxxx Signed-off-by: Matt Sealey <matt.sealey@xxxxxxx> Signed-off-by: Dave Rodgman <dave.rodgman@xxxxxxx> Cc: David S. Miller <davem@xxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Markus F.X.J. Oberhumer <markus@xxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Nitin Gupta <nitingupta910@xxxxxxxxx> Cc: Richard Purdie <rpurdie@xxxxxxxxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx> Cc: Sonny Rao <sonnyrao@xxxxxxxxxx> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/lzo/lzodefs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/lzo/lzodefs.h~lib-lzo-64-bit-ctz-on-arm64 +++ a/lib/lzo/lzodefs.h @@ -25,7 +25,7 @@ #if defined(__BIG_ENDIAN) && defined(__LITTLE_ENDIAN) #error "conflicting endian definitions" -#elif defined(CONFIG_X86_64) +#elif defined(CONFIG_X86_64) || defined(CONFIG_ARM64) #define LZO_USE_CTZ64 1 #define LZO_USE_CTZ32 1 #elif defined(CONFIG_X86) || defined(CONFIG_PPC) _ Patches currently in -mm which might be from matt.sealey@xxxxxxx are lib-lzo-64-bit-ctz-on-arm64.patch lib-lzo-fast-8-byte-copy-on-arm64.patch