Block devices may set minimum or optimal IO hints equal to blocksize; in this case there is really nothing for ext4 to do with this information (i.e. search for a block-aligned allocation?) so don't set fs geometry with single-block values. Zeev also reported that with a block-sized stripe, the ext4 allocator spends time spinning in ext4_mb_scan_aligned(), oddly enough. Reported-by: Zeev Tarantov <zeev.tarantov@xxxxxxxxx> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> --- diff --git a/misc/mke2fs.c b/misc/mke2fs.c index 9798b88..74b838c 100644 --- a/misc/mke2fs.c +++ b/misc/mke2fs.c @@ -1135,8 +1135,11 @@ static int get_device_geometry(const char *file, if ((opt_io == 0) && (psector_size > blocksize)) opt_io = psector_size; - fs_param->s_raid_stride = min_io / blocksize; - fs_param->s_raid_stripe_width = opt_io / blocksize; + /* setting stripe/stride to blocksize is pointless */ + if (min_io > blocksize) + fs_param->s_raid_stride = min_io / blocksize; + if (opt_io > blocksize) + fs_param->s_raid_stripe_width = opt_io / blocksize; rc = blkid_topology_get_alignment_offset(tp); out: -- 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
