Avi Kivity wrote:
On 03/24/2010 10:22 PM, Badari Pulavarty wrote:
Which caching mode is this? I assume data=writeback, because otherwise
you'd be doing synchronous I/O directly from the handler.
Yes. This is with default (writeback) cache model. As mentioned
earlier, readhead is helping here
and most cases, data would be ready in the pagecache.
btw, relying on readahead is problematic. The guest already issues
readahead requests, and the host will issue readahead based on that
readahead, reading far into the future.
Sure. In my tests, I did O_DIRECT in the guest - so there is no
readahead in the guest.
Thanks,
Badari
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