On Tue, 2008-03-18 at 14:58 +0100, Miklos Szeredi wrote: > > > > So the thing that's in your way is that removing a page from the radix > > > > tree doesn't imply its done writing. So perhaps we should make that > > > > distinction instead? > > > > > > > > So instead of conditionally do part of the accounting, never do it and > > > > require something like: page_writeback_complete() to be called after a > > > > successfull test_clear_page_writeback(). > > > > > > Yes, that's a possibility, but then normal filesystems miss out on the > > > small optimization provided by doing the BDI accounting functions > > > inside the same IRQ disabled region as the radix tree operation. > > > Would that have any significant performance impact? > > > > Yeah, realized that. Don't know, would have to measure it somehow... > > some archs are rather slow with disabling IRQs, but we're talking about > > writeout which should be dominated by the IO times. > > > > Its just that your proposal exposes too much guts, I'd like the > > interface to be a little higher level. > > Well, but this is the kernel, you can't really make foolproof > interfaces. If we'll go with Andrew's suggestion, I'll add comments > warning users about not touching those flags unless they know what > they are doing, OK? Yeah, I guess so :-) -- 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
