On Fri, Feb 14, 2014 at 11:47:56AM +0100, Karel Zak wrote:
> I don't like all the detection algorithm. Do we really need to allocate
> all hole size and the buffer?
>
> IMHO it would be enough to:
>
> * add posix_fadvise(... POSIX_FADV_SEQUENTIAL | POSIX_FADV_NOREUSE)
>
> * read the file in small chunks -- for example BUFSIZ and compare
> this with small empty static buffer.
>
> .. it's kernel business to read from FS/device in optimal way and I
> don't think that context switches are so critical issue when all the
> thing is about I/O.
>
> I didn't test it, so maybe I'm wrong, but the current code where we
> eat RAM seems too crazy. Comments?
.. and another issue, the current code assumes that the holes are
aligned to hole_size that we read from the file. If the hole starts
within the buffer and continues in the next chunk than it's ignored.
Karel
--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
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