Re: seq_file and exporting dynamically allocated data

From: William Lee Irwin III
Date: Mon Nov 17 2003 - 03:31:02 EST


On Mon, Nov 17, 2003 at 08:21:34AM +0000, Tigran Aivazian wrote:
> Now, since there is no way to detect EOF, other than by reading an extra
> page and discovering that it belongs to the next iteration, we have to do
> the lseek(fd, 0, SEEK_SET) anyway.
> So, the "auto-rewinding" read would only help the cases where application
> doesn't need to differentiate between samples and is happy to just
> continuously read chunks packed into pages one by one as fast as
> possible. In this case it doesn't need to lseek to 0, so auto-rewinding on
> kernel side would prevent it from slowing down.

If you're going to repeatedly read from 0 pread() sounds like a good
alternative to read() + lseek(), plus no kernel changes required to
get rid of the lseek().


-- wli
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