As you know, if any data or function are used once, we can use some keywords like __initdata for data and __init for function. -----Original Message----- From: Chao Yu [mailto:chao2.yu@xxxxxxxxxxx] Sent: Tuesday, October 29, 2013 7:52 PM To: 'Changman Lee'; jaegeuk.kim@xxxxxxxxxxx Cc: linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx Subject: RE: [f2fs-dev] [PATCH V2 RESEND] f2fs: check all ones or zeros bitmap with bitops for better mount performance Hi Lee, > -----Original Message----- > From: Changman Lee [mailto:cm224.lee@xxxxxxxxxxx] > Sent: Tuesday, October 29, 2013 3:36 PM > To: 'Chao Yu'; jaegeuk.kim@xxxxxxxxxxx > Cc: linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > 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:chao2.yu@xxxxxxxxxxx] > Sent: Tuesday, October 29, 2013 3:51 PM > To: jaegeuk.kim@xxxxxxxxxxx > Cc: linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > 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 <jaegeuk.kim@xxxxxxxxxxx> > Signed-off-by: Shu Tan <shu.tan@xxxxxxxxxxx> > Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx> > --- > 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.c > lktr > k > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- 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
