Re: [PATCH/RFC] Simplified Readahead

Nick Piggin
2004-09-25T00:45:16Z

Andrew Morton wrote:
> Steven Pratt <slpratt@austin.ibm.com> wrote:

>>Can you expand on the POSIX_FADV_WILLNEED.
>
>
> It's an application-specified readahead hint. It should ideally be
> asynchronous so the application can get some I/O underway while it's
> crunching on something else. If the queue is contested then the
> application will accidentally block when launching the readahead, which
> kinda defeats the purpose.
>
> Yes, the application will block when it does the subsequent read() anyway,
> but applications expect to block in read(). Seems saner this way.

Good point. I guess you're right.