On Mon, Aug 11, 2014 at 02:24:15AM -0400, Theodore Ts'o wrote: > On Sun, Aug 10, 2014 at 10:21:51PM -0700, Darrick J. Wong wrote: > > > > It turns out that each of the calls to ext2fs_resize_mem in the > > ext2fs_add_dir_block2() function is costing us ~2ms for each call to this > > function. I'll add a new ext2fs_init_dblist() APi that lets us specify the > > initial size of the list. This seems to reduce the fsck runtime by a few more > > seconds. > > I suspect dblist is the wrong abstraction to use here. Since the > blocks we want to read ahead are generally going to be contiguous, why > not use a rbtree bitmap, setting the blocks that should be subject to > readahead, and then use the find_first_set() function to iterate over > the bitmap? Or if you want to be even more efficient, create an > interator function which takes a bitmap and returns blocks that are > set in the bitmap, one by one. Hmm, I'll try that, though I'm almost tempted just to issue io_cache_readahead calls directly from the for loop. The only reason I'm using the list here at all is to handle the case of reading multiple groups in a flexbg (pass5 RA). --D > > - Ted > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
