lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 21 Jun 2022 10:40:30 +0800 From: hanjinke <hanjinke.666@...edance.com> To: tytso@....edu, adilger.kernel@...ger.ca Cc: linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org, lei.rao@...el.com Subject: Re: [PATCH] ext4: reuse order and buddy in mb_mark_used when buddy split hi, friendly pinging... 在 2022/6/6 下午11:53, Jinke Han 写道: > From: hanjinke <hanjinke.666@...edance.com> > > After each buddy split, mb_mark_used will search the proper order > for the block which may consume some loop in mb_find_order_for_block. > In fact, we can reuse the oder and buddy generated by the buddy split. > > Reviewed by: lei.rao@...el.com > Signed-off-by: hanjinke <hanjinke.666@...edance.com> > --- > fs/ext4/mballoc.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index 9f12f29bc346..c7ac6b269dd8 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -1933,6 +1933,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) > unsigned ret = 0; > int len0 = len; > void *buddy; > + bool split = false; > > BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); > BUG_ON(e4b->bd_group != ex->fe_group); > @@ -1957,12 +1958,16 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) > > /* let's maintain buddy itself */ > while (len) { > - ord = mb_find_order_for_block(e4b, start); > + if (!split) > + ord = mb_find_order_for_block(e4b, start); > > if (((start >> ord) << ord) == start && len >= (1 << ord)) { > /* the whole chunk may be allocated at once! */ > mlen = 1 << ord; > - buddy = mb_find_buddy(e4b, ord, &max); > + if (!split) > + buddy = mb_find_buddy(e4b, ord, &max); > + else > + split = false; > BUG_ON((start >> ord) >= max); > mb_set_bit(start >> ord, buddy); > e4b->bd_info->bb_counters[ord]--; > @@ -1989,6 +1994,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) > mb_clear_bit(cur + 1, buddy); > e4b->bd_info->bb_counters[ord]++; > e4b->bd_info->bb_counters[ord]++; > + split = true; > } > mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info); >
Powered by blists - more mailing lists