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| author | Li Dongyang <dongyangli@ddn.com> | 2020-01-26 21:52:02 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-01-26 21:52:02 -0500 |
| commit | bd828b0d44221455e667dd739e97f7f9ff9a19cf (patch) | |
| tree | c9bb24935d961930e1c49cf468b8b8fe8aa85b31 | |
| parent | 0b47dde9fd8859d8962b601e6cc8d4d705d303ab (diff) | |
| download | e2fsprogs-bd828b0d44221455e667dd739e97f7f9ff9a19cf.tar.gz | |
libext2fs: optimize ext2fs_convert_subcluster_bitmap()
For a bigalloc filesystem, converting the block bitmap from blocks
to chunks in ext2fs_convert_subcluster_bitmap() can take a long time
when the device is huge, because we test the bitmap
bit-by-bit using ext2fs_test_block_bitmap2().
Use ext2fs_find_first_set_block_bitmap2() which is more efficient
for mke2fs when the fs is mostly empty.
e2fsck can also benefit from this during pass1 block scanning.
Time taken for "mke2fs -O bigalloc,extent -C 131072 -b 4096" on a 1PB
device:
without patch:
real 27m49.457s
user 21m36.474s
sys 6m9.514s
with patch:
real 6m31.908s
user 0m1.806s
sys 6m29.697s
Signed-off-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | lib/ext2fs/gen_bitmap64.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/lib/ext2fs/gen_bitmap64.c b/lib/ext2fs/gen_bitmap64.c index 6e4d8b71d..f1dd18915 100644 --- a/lib/ext2fs/gen_bitmap64.c +++ b/lib/ext2fs/gen_bitmap64.c @@ -799,8 +799,7 @@ errcode_t ext2fs_convert_subcluster_bitmap(ext2_filsys fs, ext2fs_generic_bitmap_64 bmap, cmap; ext2fs_block_bitmap gen_bmap = *bitmap, gen_cmap; errcode_t retval; - blk64_t i, b_end, c_end; - int n, ratio; + blk64_t i, next, b_end, c_end; bmap = (ext2fs_generic_bitmap_64) gen_bmap; if (fs->cluster_ratio_bits == ext2fs_get_bitmap_granularity(gen_bmap)) @@ -817,18 +816,13 @@ errcode_t ext2fs_convert_subcluster_bitmap(ext2_filsys fs, bmap->end = bmap->real_end; c_end = cmap->end; cmap->end = cmap->real_end; - n = 0; - ratio = 1 << fs->cluster_ratio_bits; while (i < bmap->real_end) { - if (ext2fs_test_block_bitmap2(gen_bmap, i)) { - ext2fs_mark_block_bitmap2(gen_cmap, i); - i += ratio - n; - n = 0; - continue; - } - i++; n++; - if (n >= ratio) - n = 0; + retval = ext2fs_find_first_set_block_bitmap2(gen_bmap, + i, bmap->real_end, &next); + if (retval) + break; + ext2fs_mark_block_bitmap2(gen_cmap, next); + i = EXT2FS_C2B(fs, EXT2FS_B2C(fs, next) + 1); } bmap->end = b_end; cmap->end = c_end; |