On Thu, Feb 2, 2012 at 6:04 AM, Allison Henderson <achender@xxxxxxxxxxxxxxxxxx> wrote: > On 02/01/2012 12:26 AM, Tao Ma wrote: >> >> Hi Allison, >> On 02/01/2012 06:33 AM, Allison Henderson wrote: >>> >>> Hi Yongqiang, >>> >>> I've have been working on an extent lock implementation that uses an >>> rbtree to keep track of locked extents, and I think I will probably end >>> up with a something similar to the tree that you've already set up for >>> delayed extents. So I wanted to send a note out to see what folks would >>> think about the idea of merging the two solutions. >>> >>> If we did this, the tree would get a little more complex in that it >>> would have to keep track of more than just delayed extents. It would >>> have to keep track of all extents and the processes that are waiting on >>> them. So I guess it would kind of turn into an extent status tree. I >>> also realize that some folks wanted to see range locks go into /lib as >>> general purpose code so that other filesystems or kernel code could use >>> it too, but the advantage to this approach would be one less tree for >>> ext4 to keep track of. Any thoughts? >> >> We (Taobao) are very interested in this stuff and it should benefit >> several of our workload(It is on our todo list for a long time). I guess >> Yongqiang's solution is a little bit limited to the only delayed extent >> case, and your new solution at least has 2 more benefits: >> 1. improve the direct i/o read/write >> 2. speed up the extent search since now we only cache one in >> ei_cached_extent. >> >> So please go ahead with your new solution. btw, do you have any timeline >> for it? We are glad to provide any help if needed. >> >> Thanks >> Tao >> > > Thx all for the feed back, it sounds like there will be a lot of benefits to > extending Yongqiang's delayed extent tree, so I will work on a solution > based on that patch set. Unfortunately though, I cannot give a time frame > for this work item at the moment. There are currently some other business > needs that may take priority over this one, and until those have been > decided, I cannot make any promises at this point in time. But I will work > as quickly as I can with it since it is currently on my plate, and I will > keep folks updated. At the moment, feed back and guidance is most helpful > to me. Also, since the delayed extent solution is now a dependency for my > solution, anything to help get that reviewed and merged would help me too. > Yongqiang, does the set still need review? I think I recall Ted saying it It passed xfstests last year and I think you can go ahead on the set. It seems that your changes are a lot, so maybe we can merge the whole set until your work is done. At least, your work and the merging work can be undertaken concurrently. If you need any help, I am available. Yongqiang. > was still on his list of things to look at. Im sure I will give it some > good exercise here too. Thx all for your help! :) > > Allison Henderson > -- Best Wishes Yongqiang Yang -- 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
