On Sat, Jun 06, 2015 at 08:42:33AM +0800, Ming Lei wrote: > Both ITER_KVEC and ITER_BVEC doesn't mean the pages are kernel > page, for example of loop and swap. That is why this patch is more flexiable, > and won't cause regression since the users may have different dirtying > rules as you mentioned last time. > > http://marc.info/?t=143093223200001&r=1&w=2
Again, we never dirty pages for the caller when doing general purpose kernel I/O. For loop we either don't need it (totally in-kernel block I/O) or the caller takes care of it (direct I/O on the loop device). The swap code currently only uses ->direct_IO and thus isn't affected by this flag. If we use it for write the low-level I/O code should not dirty the page either. So to repeat myself: for the current state of affairs adding a flag that every sensible user has to set is a horrible interface. If for some unforseen reason we'll need the flag later on it should have reverse polarity, and only be added when needed. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
