Messages in this thread |  | | Date | Thu, 5 Sep 2002 20:31:17 +0200 | From | Jens Axboe <> | Subject | Re: One more bio for for floppy users in 2.5.33.. |
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On Thu, Sep 05 2002, Linus Torvalds wrote: > > OK. But still, I don't see why we need partial BIO completions. If > > we say that the basic unit of completion is a whole BIO, then readahead > > can then manage latency via the outgoing bio size. > > But that's horrible. The floppy driver can take huge bio's no problem, and > limiting bio sizes to track sizes would be a huge pain in the driver for > no good reason. In fact, it would be pretty much impossible, since the > tracks aren't even page-aligned. > > So limiting bio's fundamentally _cannot_ do the right thing. While adding > two lines of code _can_.
I agree that partial completions are the right thing to do here, and in fact this is how the interface was originally remember?
However, I don't see how this is a two-liner change. Basically you are changing bi_end_io() from a completion to partial completion invokation, which requires changing (and complicating) all of them. Just adding a sector count to bio_endio() does not enable that to partially complete some pages. What am I missing?
Jens
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