On Mon, 2004-09-27 at 08:30, Steven Pratt wrote:Ok, great.
Ram Pai wrote:
On Fri, 24 Sep 2004, Ram Pai wrote:
On Thu, 23 Sep 2004, Steven Pratt wrote:
..snip..
To summarize you noticed 3 problems:Yes.
1. page cache hits not handled properly.
2. readahead thrashing not accounted.
3. read congestion not accounted.
Currently both the patches do not handle all the above cases.No, thrashing was handled in the first patch, and both thrashing and page cache hits are handled in the second. Also, it seems to be the consensus that on normal I/O ignoring queue congestion is the right behavior.
So if your patch performs much better than the current one, thanI agree, we need more people to test this.
it is the winner anyway. But past experience has shown that some
benchmark gets a hit for any small change. This happens to be tooo big
a change.
I will fix the 3 problems you discovered in the current code.
And lets compare the two results.
However you have more features inNo, I think that is it.
your patch which will be the differentiating factor between the two
versions.
1. exponential increase and decrease of window size 2. overlapped read of current window and readahead window.
3. fixed slow-read path.
4. anything else?
The readsize parameter comes in handy to incorporate theYes, without it I think you still need to do the average calculations that you do today.
the above features.