Hi Gu, > -----Original Message----- > From: Gu Zheng [mailto:guz.fnst@xxxxxxxxxxxxxx] > Sent: Thursday, October 24, 2013 6:04 PM > To: Chao Yu > Cc: jaegeuk.kim@xxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx; '谭姝' > Subject: Re: [f2fs-dev] [PATCH V2] f2fs: check all ones or zeros bitmap with > bitops for better mount performance > > Hi Yu, > On 10/24/2013 04:21 PM, Chao Yu wrote: > > > Previously, check_block_count check valid_map with bit data type in common > scenario that sit has all ones or zeros bitmap, it makes low mount > performance. > > So let's check the special bitmap with integer data type instead of the bit one. > > > > v2: > > use find_next_bit_le/find_next_zero_bit_le for better performance and > readable as Jaegeuk suggested. > > If so, how about using find_first_{zero_}bit_le instead? It's more neat. It seems more neat. I will take it, thanks. > > Regards, > Gu > > > > > Suggested-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx> > > Signed-off-by: Tan Shu <shu.tan@xxxxxxxxxxx> > > Signed-off-by: Yu Chao <chao2.yu@xxxxxxxxxxx> > > --- > > fs/f2fs/segment.h | 17 +++++++++++++++++ > > 1 file changed, 17 insertions(+) > > > > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index > > 7f94d78..d25b6af 100644 > > --- a/fs/f2fs/segment.h > > +++ b/fs/f2fs/segment.h > > @@ -552,6 +552,23 @@ static inline void check_block_count(struct > f2fs_sb_info *sbi, > > /* check boundary of a given segment number */ > > BUG_ON(segno > end_segno); > > > > + /* check all ones or zeros valid_map */ > > + if (GET_SIT_VBLOCKS(raw_sit) == 0) { > > + int pos = find_next_bit_le(&raw_sit->valid_map, > > + sbi->blocks_per_seg, > > + 0); > > + if (pos != sbi->blocks_per_seg) > > + BUG(); > > + return; > > + } else if (GET_SIT_VBLOCKS(raw_sit) == sbi->blocks_per_seg) { > > + int pos = find_next_zero_bit_le(&raw_sit->valid_map, > > + sbi->blocks_per_seg, > > + 0); > > + if (pos != sbi->blocks_per_seg) > > + BUG(); > > + return; > > + } > > + > > /* check bitmap with valid block count */ > > for (i = 0; i < sbi->blocks_per_seg; i++) > > if (f2fs_test_bit(i, raw_sit->valid_map)) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
