2013/4/25, Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>: > Previously, background GC submits many 4KB read requests to load victim > blocks > and/or its (i)node blocks. > > ... > f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb61, blkaddr = 0x3b964ed > f2fs_gc : block_rq_complete: 8,16 R () 499854968 + 8 [0] > f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb6f, blkaddr = 0x3b964ee > f2fs_gc : block_rq_complete: 8,16 R () 499854976 + 8 [0] > f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb79, blkaddr = 0x3b964ef > f2fs_gc : block_rq_complete: 8,16 R () 499854984 + 8 [0] > ... > > However, by the fact that many IOs are sequential, we can give a chance to > merge > the IOs by IO scheduler. > In order to do that, let's use blk_plug. > > ... > f2fs_gc : f2fs_iget: ino = 143 > f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c6, blkaddr = 0x2e6ee > f2fs_gc : f2fs_iget: ino = 143 > f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c7, blkaddr = 0x2e6ef > <idle> : block_rq_complete: 8,16 R () 1519616 + 8 [0] > <idle> : block_rq_complete: 8,16 R () 1519848 + 8 [0] > <idle> : block_rq_complete: 8,16 R () 1520432 + 96 [0] > <idle> : block_rq_complete: 8,16 R () 1520536 + 104 [0] > <idle> : block_rq_complete: 8,16 R () 1521008 + 112 [0] > <idle> : block_rq_complete: 8,16 R () 1521440 + 152 [0] > <idle> : block_rq_complete: 8,16 R () 1521688 + 144 [0] > <idle> : block_rq_complete: 8,16 R () 1522128 + 192 [0] > <idle> : block_rq_complete: 8,16 R () 1523256 + 328 [0] > ... > > Note that this issue should be addressed in checkpoint, and some readahead > flows too. > > Signed-off-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx> Looks reasonable to me :) Reviewed-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> Thanks~ -- 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
