On Wed, Jul 13, 2016 at 04:08:55PM +0200, Daniel Borkmann wrote: > Hi Peter, > > On 07/13/2016 03:42 PM, Peter Zijlstra wrote: > > > >Ok so the nonlinear thing was it doing _two_ copies, one the regular > >__output_copy() on raw->data and second the optional fragment thingy > >using __output_custom(). > > > >Would something like this work instead? > > > >It does the nonlinear thing and the custom copy function thing but > >allows more than 2 fragments and allows each fragment to have a custom > >copy. > > > >It doesn't look obviously more expensive; it has the one ->copy branch > >extra, but then it doesn't recompute the sizes. > > Yes, that would work as well on a quick glance with diff just a bit > bigger, but more generic this way. Do you want me to adapt this into > the first patch?
Please. > One question below: > > >- u64 zero = 0; > >- if (real_size - raw_size) > >- __output_copy(handle, &zero, real_size - > >raw_size); > > We still need the zero padding here from above with the computed > raw->size, right? Ah, yes, we need some __output*() in order to advance the handle offset. We don't _need_ to copy the 0s, but I doubt __output_skip() is much cheaper for these 1-3 bytes worth of data; we've already touched that line anyway.
