On Thu, 2 Oct 2008 23:48:56 +0530 "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> wrote: > > > > For a 4.5GB streaming buffered write, this printk inside > > ext4_da_writepage shows up 37,2429 times in /var/log/messages. > > > > Part of that can happen due to shrink_page_list -> pageout -> writepagee > call back with lots of unallocated buffer_heads(blocks). That workload shouldn't be using that code path much at all. It's supposed to be the case that pdflush and balance_dirty_pages() do most of the writeback work. And that _used_ to be the case, but we broke it. It happened several years ago and I wasn't able to provoke anyone into finding out why. iirc the XFS guys noticed it because their throughput was fairly badly affected. -- 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
