Hi Kim, > -----Original Message----- > From: Jaegeuk Kim [mailto:jaegeuk.kim@xxxxxxxxxxx] > Sent: Wednesday, October 23, 2013 5:32 PM > To: Chao Yu > Cc: linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; '谭姝' > Subject: RE: [f2fs-dev] [PATCH] f2fs: check all ones or zeros bitmap with integer > data type for better mount performance > > Hi, > > 2013-10-23 (수), 11:23 +0800, Chao Yu: > > Hi, Kim: > > > > > -----Original Message----- > > > From: Jaegeuk Kim [mailto:jaegeuk.kim@xxxxxxxxxxx] > > > Sent: Tuesday, October 22, 2013 8:24 PM > > > To: Chao Yu > > > Cc: linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx; > > > linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; 谭姝 > > > Subject: Re: [f2fs-dev] [PATCH] f2fs: check all ones or zeros bitmap > > > with integer data type for better mount performance > > > > > > Hi, > > > > > > 2013-10-22 (화), 17:28 +0800, Chao Yu: > > > > 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. > > > > > > > > Signed-off-by: Tan Shu <shu.tan@xxxxxxxxxxx> > > > > Signed-off-by: Yu Chao <chao2.yu@xxxxxxxxxxx> > > > > --- > > > > fs/f2fs/segment.h | 13 +++++++++++++ > > > > 1 file changed, 13 insertions(+) > > > > > > > > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index > > > > 7f94d78..d43ab9f 100644 > > > > --- a/fs/f2fs/segment.h > > > > +++ b/fs/f2fs/segment.h > > > > @@ -543,6 +543,7 @@ static inline void check_block_count(struct > > > > f2fs_sb_info *sbi, { > > > > struct f2fs_sm_info *sm_info = SM_I(sbi); > > > > unsigned int end_segno = sm_info->segment_count - 1; > > > > + int *valid_map = (int *)raw_sit->valid_map; > > > > int valid_blocks = 0; > > > > int i; > > > > > > > > @@ -552,6 +553,19 @@ 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) { > > > > + for (i = 0; i < SIT_VBLOCK_MAP_SIZE / sizeof(int); i++) > > > > > > We cannot guarantee all the time that SIT_VBLOCK_MAP_SIZE is > > > multiple of sizeof(int). > > Well, It's really large changes for f2fs if SIT_VBLOCK_MAP_SIZE value is being > modified. > > But, it can be changed. > Please do not add any unnecessary assumption. Got it, sorry for the unmeaning assumption. > > > > > > How about using memcmp() with __u8? > > Do you mean that we can alloc all zeros or ones memory in > > SIT_VBLOCK_MAP_SIZE size, then memcmp() it with sit bitmap by __u8? > > Yap. > Ah, but there is another one. > It would be better to use find_next_bit_le() and find_next_zero_bit_le(). > Any idea? Good point. I try to use memcmp(bitmap, bitmap+1, size-1) and bitmap[0], But yours got better performance and readable. Thanks. > > > > > > > > > > + if (unlikely(valid_map[i] != 0)) > > > > + BUG(); > > > > + return; > > > > + } else if (GET_SIT_VBLOCKS(raw_sit) == sbi->blocks_per_seg) { > > > > + for (i = 0; i < SIT_VBLOCK_MAP_SIZE / sizeof(int); i++) > > > > + if (unlikely(valid_map[i] != -1)) > > > > + 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 > > > > > > -- > > > Jaegeuk Kim > > > Samsung > > > > -- > Jaegeuk Kim > Samsung -- 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
