The branch main has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=996fa9fb4ec47995e89d2089e6084d37dcb1033c
commit 996fa9fb4ec47995e89d2089e6084d37dcb1033c Author: Elliott Mitchell <[email protected]> AuthorDate: 2024-05-09 04:47:09 +0000 Commit: Warner Losh <[email protected]> CommitDate: 2024-05-21 23:52:27 +0000 kern/rman: update rman_make_alignment_flags() The flsl() function makes use of hardware functionality to compute the value faster than this loop. The only deviation from flsl() is at 0. Reviewed by: imp,jhb Pull Request: https://github.com/freebsd/freebsd-src/pull/1224 --- sys/kern/subr_rman.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/sys/kern/subr_rman.c b/sys/kern/subr_rman.c index 2019e19090c0..508152f74002 100644 --- a/sys/kern/subr_rman.c +++ b/sys/kern/subr_rman.c @@ -776,19 +776,14 @@ rman_release_resource(struct resource *re) uint32_t rman_make_alignment_flags(uint32_t size) { - int i; /* * Find the hightest bit set, and add one if more than one bit * set. We're effectively computing the ceil(log2(size)) here. */ - for (i = 31; i > 0; i--) - if ((1 << i) & size) - break; - if (~(1 << i) & size) - i++; - - return(RF_ALIGNMENT_LOG2(i)); + if (__predict_false(size == 0)) + return (0); + return (RF_ALIGNMENT_LOG2(flsl(size - 1))); } rman_res_t
