Quoting Chris Mason (2013-04-01 11:45:41) > Quoting Eric Sandeen (2013-04-01 11:18:51) > > On 4/1/13 6:06 AM, Dmitry Monakhov wrote: > > > > > 1)Do we really have to use WRITE_SYNC in case of WB_SYNC_ALL ? > > Yes? The stuff we wait on should be WRITE_SYNC. > > > > > ... > > > > > 2) Why don't we have writepages for non delalloc case ? > > > > ... > > > > I'd add: > > > > 3) Why do we have a "nodelalloc" mount option at all? > > > > but then I thought: > > > > Is it also this bad when using the ext4 driver to run an ext3 fs? > > Quick comparison on a single iodrive: On the theory that writepages is the problem try echo 1 > /sys/block/xxx/queue/rotational. With request merging on here in nodelalloc mode: dd if=/dev/zero of=foo bs=1M count=1024 conv=fsync,notrunc 1073741824 bytes (1.1 GB) copied, 2.53741 s, 423 MB/s dd if=/dev/zero of=foo bs=1M count=1024 conv=fsync,notrunc 1073741824 bytes (1.1 GB) copied, 1.37795 s, 779 MB/s -chris -- 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