On Tue, Jan 28, 2025 at 11:46:29AM -0500, Yury Norov wrote:
> cpumask_next_wrap() is overly complicated, comparing to it's generic
> version find_next_bit_wrap(), not mentioning it duplicates the above.
> It roots to the times when the function was used in the implementation
> of for_each_cpu_wrap() iterator. The function has 2 additional parameters
> that were used to catch loop termination condition for the iterator.
> (Although, only one is needed.)
>
> Since 4fe49b3b97c262 ("lib/bitmap: introduce for_each_set_bit_wrap()
> macro"), for_each_cpu_wrap() is wired to corresponding generic
> wrapping bitmap iterator, and additional complexity of
> cpumask_next_wrap() is not needed anymore.
>
> All existing users call cpumask_next_wrap() in a manner that makes
> it possible to turn it to a straight and simple alias to
> find_next_bit_wrap().
>
> This series replaces historical 4-parameter cpumask_next_wrap() with a
> thin 2-parameter wrapper around find_next_bit_wrap().
>
> Where it's possible to use for_each_cpu_wrap() iterator, the code is
> switched to use it because it's always preferable to use iterators over
> open loops.
>
> This series touches various scattered subsystems and To-list for the
> whole series is quite a long. To minimize noise, I send cover-letter and
> key patches #5 and 6 to every person involved. All other patches are sent
> individually to those pointed by scripts/get_maintainers.pl.
>
> I'd like to move the series with my bitmap-for-next branch as a whole.
virtio-net changes are straight-forward, so
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> v1: https://lore.kernel.org/netdev/20241228184949.31582-1-yury.norov@xxxxxxxxx/T/
> v2:
> - rebase on top of today's origin/master;
> - drop #v1-10: not needed since v6.14 @ Sagi Grinberg;
> - #2, #3: fix picking next unused CPU @ Nick Child;
> - fix typos, cleanup comments @ Bjorn Helgaas, Alexander Gordeev;
> - CC Christoph Hellwig for the whole series.
>
> Yury Norov (13):
> objpool: rework objpool_pop()
> virtio_net: simplify virtnet_set_affinity()
> ibmvnic: simplify ibmvnic_set_queue_affinity()
> powerpc/xmon: simplify xmon_batch_next_cpu()
> cpumask: deprecate cpumask_next_wrap()
> cpumask: re-introduce cpumask_next{,_and}_wrap()
> cpumask: use cpumask_next_wrap() where appropriate
> padata: switch padata_find_next() to using cpumask_next_wrap()
> s390: switch stop_machine_yield() to using cpumask_next_wrap()
> scsi: lpfc: switch lpfc_irq_rebalance() to using cpumask_next_wrap()
> scsi: lpfc: rework lpfc_next_{online,present}_cpu()
> PCI: hv: Switch hv_compose_multi_msi_req_get_cpu() to using
> cpumask_next_wrap()
> cpumask: drop cpumask_next_wrap_old()
>
> arch/powerpc/xmon/xmon.c | 6 +--
> arch/s390/kernel/processor.c | 2 +-
> drivers/net/ethernet/ibm/ibmvnic.c | 18 +++++---
> drivers/net/virtio_net.c | 12 ++---
> drivers/pci/controller/pci-hyperv.c | 3 +-
> drivers/scsi/lpfc/lpfc.h | 23 +++-------
> drivers/scsi/lpfc/lpfc_init.c | 2 +-
> include/linux/cpumask.h | 69 ++++++++++++++++++++---------
> include/linux/objpool.h | 7 ++-
> kernel/padata.c | 2 +-
> lib/cpumask.c | 37 +---------------
> 11 files changed, 81 insertions(+), 100 deletions(-)
>
> --
> 2.43.0
