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: Ext4 (defaults): # dd if=/dev/zero of=foo bs=1M count=1024 conv=fsync,notrunc 1073741824 bytes (1.1 GB) copied, 1.95442 s, 549 MB/s # dd if=/dev/zero of=foo bs=1M count=1024 conv=fsync,notrunc 1073741824 bytes (1.1 GB) copied, 1.45012 s, 740 MB/s Ext4 (nodelalloc): dd if=/dev/zero of=foo bs=1M count=1024 conv=fsync,notrunc 1073741824 bytes (1.1 GB) copied, 2.97308 s, 361 MB/s # dd if=/dev/zero of=foo bs=1M count=1024 conv=fsync,notrunc 1073741824 bytes (1.1 GB) copied, 1.76617 s, 608 MB/s # dd if=/dev/zero of=foo bs=1M count=1024 conv=fsync,notrunc XFS gives 628, 733MB/s Btrfs gives 659, 635MB/s -- since we're doing fsync, this includes all the crcs for the data. Ext3 mounted by ext4.ko: 291, 467MB/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
