---- 在 星期一, 2019-09-23 18:02:53 Jan Kara <j...@suse.cz> 撰写 ---- > On Sat 21-09-19 09:56:28, Chengguang Xu wrote: > > Code cleanup for hash bits calculation by > > calling rounddown_pow_of_two() and ilog2() > > > > Signed-off-by: Chengguang Xu <cgxu...@zoho.com.cn> > > Thanks for the patch! One comment below: > > > diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c > > index 6e826b454082..679dd3b5db70 100644 > > --- a/fs/quota/dquot.c > > +++ b/fs/quota/dquot.c > > @@ -2983,13 +2983,9 @@ static int __init dquot_init(void) > > > > /* Find power-of-two hlist_heads which can fit into allocation */ > > nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); > > - dq_hash_bits = 0; > > - do { > > - dq_hash_bits++; > > - } while (nr_hash >> dq_hash_bits); > > - dq_hash_bits--; > > + nr_hash = rounddown_pow_of_two(nr_hash); > > + dq_hash_bits = ilog2(nr_hash); > > > > - nr_hash = 1UL << dq_hash_bits; > > Why not just: > dq_hash_bits = ilog2(nr_hash); > nr_hash = 1UL << dq_hash_bits; > > That way we need to compute fls() only once... Yeah, you are right, I'll update in v2.
Thanks, Chengguang