Hi Lee, > -----Original Message----- > From: Changman Lee [mailto:[email protected]] > Sent: Tuesday, October 29, 2013 3:36 PM > To: 'Chao Yu'; [email protected] > Cc: [email protected]; [email protected]; > [email protected] > Subject: RE: [f2fs-dev] [PATCH V2 RESEND] f2fs: check all ones or zeros bitmap > with bitops for better mount performance > > Review attached patch, please.
Could we hide the pre calculated value by generating it in allocated memory by func, because the value will be no use after build_sit_entries(); Regards Yu > > -----Original Message----- > From: Chao Yu [mailto:[email protected]] > Sent: Tuesday, October 29, 2013 3:51 PM > To: [email protected] > Cc: [email protected]; [email protected]; > [email protected] > Subject: [f2fs-dev] [PATCH V2 RESEND] f2fs: check all ones or zeros bitmap with > bitops for better mount performance > > 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. > > v1-->v2: > use find_next_{zero_}bit_le for better performance and readable as > Jaegeuk suggested. > use neat logogram in comment as Gu Zheng suggested. > search continuous ones or zeros for better performance when checking > mixed bitmap. > > Suggested-by: Jaegeuk Kim <[email protected]> > Signed-off-by: Shu Tan <[email protected]> > Signed-off-by: Chao Yu <[email protected]> > --- > fs/f2fs/segment.h | 19 +++++++++++++++---- > 1 file changed, 15 insertions(+), 4 deletions(-) > > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index abe7094..a7abfa8 > 100644 > --- a/fs/f2fs/segment.h > +++ b/fs/f2fs/segment.h > @@ -550,8 +550,9 @@ 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; > + bool is_valid = test_bit_le(0, raw_sit->valid_map) ? true : false; > int valid_blocks = 0; > - int i; > + int cur_pos = 0, next_pos; > > /* check segment usage */ > BUG_ON(GET_SIT_VBLOCKS(raw_sit) > sbi->blocks_per_seg); @@ -560,9 > +561,19 @@ static inline void check_block_count(struct f2fs_sb_info > +*sbi, > BUG_ON(segno > end_segno); > > /* check bitmap with valid block count */ > - for (i = 0; i < sbi->blocks_per_seg; i++) > - if (f2fs_test_bit(i, raw_sit->valid_map)) > - valid_blocks++; > + do { > + if (is_valid) { > + next_pos = > find_next_zero_bit_le(&raw_sit->valid_map, > + sbi->blocks_per_seg, > + cur_pos); > + valid_blocks += next_pos - cur_pos; > + } else > + next_pos = find_next_bit_le(&raw_sit->valid_map, > + sbi->blocks_per_seg, > + cur_pos); > + cur_pos = next_pos; > + is_valid = !is_valid; > + } while (cur_pos < sbi->blocks_per_seg); > BUG_ON(GET_SIT_VBLOCKS(raw_sit) != valid_blocks); } > > -- > 1.7.9.5 > > > ---------------------------------------------------------------------------- > -- > Android is increasing in popularity, but the open development platform that > developers love is also attractive to malware creators. Download this white > paper to learn more about secure code signing practices that can help keep > Android apps secure. > http://pubads.g.doubleclick.net/gampad/clk?id=65839951&iu=/4140/ostg.clktr > k > _______________________________________________ > Linux-f2fs-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ------------------------------------------------------------------------------ Android is increasing in popularity, but the open development platform that developers love is also attractive to malware creators. Download this white paper to learn more about secure code signing practices that can help keep Android apps secure. http://pubads.g.doubleclick.net/gampad/clk?id=65839951&iu=/4140/ostg.clktrk _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
