On Mon, Aug 13 2007, Daniel Phillips wrote: > On Monday 13 August 2007 02:13, Jens Axboe wrote: > > On Mon, Aug 13 2007, Daniel Phillips wrote: > > > On Monday 13 August 2007 00:45, Jens Axboe wrote: > > > > On Mon, Aug 13 2007, Jens Axboe wrote: > > > > > > You did not comment on the one about putting the bio > > > > > > destructor in the ->endio handler, which looks dead simple. > > > > > > The majority of cases just use the default endio handler and > > > > > > the default destructor. Of the remaining cases, where a > > > > > > specialized destructor is needed, typically a specialized > > > > > > endio handler is too, so combining is free. There are few if > > > > > > any cases where a new specialized endio handler would need to > > > > > > be written. > > > > > > > > > > We could do that without too much work, I agree. > > > > > > > > But that idea fails as well, since reference counts and IO > > > > completion are two completely seperate entities. So unless end IO > > > > just happens to be the last user holding a reference to the bio, > > > > you cannot free it. > > > > > > That is not a problem. When bio_put hits zero it calls ->endio > > > instead of the destructor. The ->endio sees that the count is zero > > > and destroys the bio. > > > > You can't be serious? You'd stall end io completion notification > > because someone holds a reference to a bio. > > Of course not. Nothing I said stops endio from being called in the > usual way as well. For this to work, endio just needs to know that one > call means "end" and the other means "destroy", this is trivial. Sorry Daniel, but your suggestions would do nothing more than uglify the code and design. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
