Re: [PATCH v2 0/9] s390: vfio-ccw code rework

Cornelia Huck
2019-06-17T13:32:31Z

On Thu, 6 Jun 2019 22:28:22 +0200
Eric Farman <farman@linux.ibm.com> wrote:

> Now that we've gotten a lot of other series either merged or
> pending for the next merge window, I'd like to revisit some
> code simplification that I started many moons ago.
>
> In that first series, a couple of fixes got merged into 4.20,
> a couple more got some "seems okay" acks/reviews, and the rest
> were nearly forgotten about. I dusted them off and did quite a
> bit of rework to make things a little more sequential and
> providing a better narrative (I think) based on the lessons we
> learned in my earlier changes. Because of this rework, the
> acks/reviews on the first version didn't really translate to the
> code that exists here (patch 1 being the closest exception), so
> I didn't apply any of them here. The end result is mostly the
> same as before, but now looks like this:
>
> Patch summary:
> 1: Squash duplicate code
> 2-4: Remove duplicate code in CCW processor
> 5-7: Remove one layer of nested arrays
> 8-9: Combine direct/indirect addressing CCW processors
>
> Using 5.2.0-rc3 as a base plus the vfio-ccw branch of recent fixes,
> we shrink the code quite a bit (8.7% according to the bloat-o-meter),
> and we remove one set of mallocs/frees on the I/O path by removing
> one layer of the nested arrays. There are no functional/behavioral
> changes with this series; all the tests that I would run previously
> continue to pass/fail as they today.
>
> Changelog:
> v1/RFC->v2:
> - [Eric] Dropped first two patches, as they have been merged
> - [Eric] Shuffling of patches for readability/understandability
> - [Halil] Actually added meaningful comments/commit messages
> in the patches
> v1/RFC: https://patchwork.kernel.org/cover/10675251/
>
> Eric Farman (9):
> s390/cio: Squash cp_free() and cp_unpin_free()
> s390/cio: Refactor the routine that handles TIC CCWs
> s390/cio: Generalize the TIC handler
> s390/cio: Use generalized CCW handler in cp_init()
> vfio-ccw: Rearrange pfn_array and pfn_array_table arrays
> vfio-ccw: Adjust the first IDAW outside of the nested loops
> vfio-ccw: Remove pfn_array_table
> vfio-ccw: Rearrange IDAL allocation in direct CCW
> s390/cio: Combine direct and indirect CCW paths
>
> drivers/s390/cio/vfio_ccw_cp.c | 313 +++++++++++----------------------
> 1 file changed, 102 insertions(+), 211 deletions(-)
>

Thanks, applied.