On Wed, Sep 19, 2012 at 02:34:52PM -0400, Theodore Ts'o wrote: > On Wed, Aug 22, 2012 at 02:05:39PM +0800, Zheng Liu wrote: > > + * 3. performance analysis > > + * -- overhead > > + * 1. Apart from operations on a delayed extent tree, we need to > > + * down_write(inode->i_data_sem) in delayed write path to maintain delayed > > + * extent tree, this can have impact on parallel read-write and write-write > > I'm working on going through this patch set now, and I'm not sure this > is worth holding back on this patch series, but I am really concerned > about the performance impact of this.... it would definitely show up > on some of the scalability testing that Eric Whitney had been doing, > for example. Sorry, maybe I miss some mails. Could you please tell me where I can find Eric's mail. Thanks. > > Given that operations on the delayed extent tree should be fast, > instead of using a mutex, any reason why we can't just add a new > spinlock (I'm not even sure we need a rw_spinlock here) to the > ext4_inode_info structure and use that to serialize operations on the > delayed extent tree? Thanks for your comment. I will fix it. Regards, Zheng -- 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
