From: Alexey Lyashkov <alexey.lyashkov@xxxxxxxxxxx>
There are ~37k of random IOs with meta_bg option on 300T target.
Debugfs requires 20 minutes to be started. Enabling readahead for
group blocks metadata save time dramatically. Only 12s to start.
Signed-off-by: Alexey Lyashkov <alexey.lyashkov@xxxxxxxxxxx>
---
lib/ext2fs/openfs.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
index ba501e6..f158b0a 100644
--- a/lib/ext2fs/openfs.c
+++ b/lib/ext2fs/openfs.c
@@ -399,6 +399,12 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
#endif
dest += fs->blocksize*first_meta_bg;
}
+
+ for (i = first_meta_bg ; i < fs->desc_blocks; i++) {
+ blk = ext2fs_descriptor_block_loc2(fs, group_block, i);
+ io_channel_cache_readahead(fs->io, blk, 1);
+ }
+
for (i=first_meta_bg ; i < fs->desc_blocks; i++) {
blk = ext2fs_descriptor_block_loc2(fs, group_block, i);
retval = io_channel_read_blk64(fs->io, blk, 1, dest);
--
1.7.1
