Hi, Kim: > -----Original Message----- > From: Jaegeuk Kim [mailto:jaegeuk....@samsung.com] > Sent: Tuesday, October 22, 2013 8:24 PM > To: Chao Yu > Cc: linux-f2fs-devel@lists.sourceforge.net; linux-fsde...@vger.kernel.org; > linux-ker...@vger.kernel.org; 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....@samsung.com> > > Signed-off-by: Yu Chao <chao2...@samsung.com> > > --- > > 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.
> 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? > > > + 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 majord...@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > Jaegeuk Kim > Samsung ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel