(removed lsf-pc@xxxxxxxxxxxxxxxxxxxxxxxxxx because this really isn't program committee matter) On Wed, Feb 1, 2012 at 11:52 PM, Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote: > Unfortunately the memcg partitioning could fundamentally make the > dirty throttling more bumpy. > > Imagine 10 memcgs each with > > - memcg_dirty_limit=50MB > - 1 dd dirty task > > The flusher thread will be working on 10 inodes in turn, each time > grabbing the next inode and taking ~0.5s to write ~50MB of its dirty > pages to the disk. So each inode will be flushed on every ~5s. Does the flusher thread need to write 50MB/inode in this case? Would there be problems interleaving writes by declaring some max write limit (e.g. 8 MiB/write). Such interleaving would be beneficial if there are multiple memcg expecting service from the single bdi flusher thread. I suspect certain filesystems might have increased fragmentation with this, but I am not sure if appending writes can easily expand an extent. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>