Messages in this thread |  | | | Date | Tue, 03 Mar 2009 15:58:23 +1100 | | From | Aaron Carroll <> | | Subject | Re: The difference of request dir between AS and Deadline I/O scheduler? |
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谢纲 wrote: > On Tue, Mar 3, 2009 at 12:21 PM, Aaron Carroll <aaronc@cse.unsw.edu.au> wrote: >> � wrote: >>> Hi, >>> >>> I'm little confused about the defination of request dir in AS and >>> Deadline I/O scheduler. >>> In AS, the request dir is defined by wheher it's sync: >>> >>> data_dir = rq_is_sync(rq); >>> >>> But in Deadline, the requests are grouped by read and write. >>> >>> Why is there the difference since AS is an extension of Deadline? >>> what's the consideration? >> I also thought it was silly to have different behaviours, so I tried >> the following patch that makes deadline use sync/async instead of >> read/write. All the benchmarks I tried showed that performance >> dropped or remained constant at best, so I didn't propose it. >> Maybe you will have more luck... > Hello, > Which benchmark tool do you use? I'd like to have a try. I think the > I/O behavior is an important factor which can affect the performance.
I can't find the original results, but from memory I tried FIO (many random readers with various I/O sizes), postmark, and compilebench on a single-disk and 10-disk hardware RAID system.
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