Re: [PATCH v2 4/4] net: fix opencoded for_each_and_bit() in __netif_set_xps_queue()

From: Michael S. Tsirkin
Date: Fri Oct 14 2022 - 05:39:05 EST


On Thu, Oct 13, 2022 at 04:43:48PM -0700, Yury Norov wrote:
> Replace opencoded bitmap traversing and drop unused
> netif_attrmask_next*() functions
>
> Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>

I think you want to document, here, that this fixes a warning.
Additionally, add a Fixes: tag.


> ---
> include/linux/netdevice.h | 46 ---------------------------------------
> net/core/dev.c | 3 +--
> 2 files changed, 1 insertion(+), 48 deletions(-)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 53d738f66159..5db2b6de7308 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -3648,52 +3648,6 @@ static inline bool netif_attr_test_online(unsigned long j,
>
> return (j < nr_bits);
> }
> -
> -/**
> - * netif_attrmask_next - get the next CPU/Rx queue in a cpu/Rx queues mask
> - * @n: CPU/Rx queue index
> - * @srcp: the cpumask/Rx queue mask pointer
> - * @nr_bits: number of bits in the bitmask
> - *
> - * Returns >= nr_bits if no further CPUs/Rx queues set.
> - */
> -static inline unsigned int netif_attrmask_next(int n, const unsigned long *srcp,
> - unsigned int nr_bits)
> -{
> - /* n is a prior cpu */
> - cpu_max_bits_warn(n + 1, nr_bits);
> -
> - if (srcp)
> - return find_next_bit(srcp, nr_bits, n + 1);
> -
> - return n + 1;
> -}
> -
> -/**
> - * netif_attrmask_next_and - get the next CPU/Rx queue in \*src1p & \*src2p
> - * @n: CPU/Rx queue index
> - * @src1p: the first CPUs/Rx queues mask pointer
> - * @src2p: the second CPUs/Rx queues mask pointer
> - * @nr_bits: number of bits in the bitmask
> - *
> - * Returns >= nr_bits if no further CPUs/Rx queues set in both.
> - */
> -static inline int netif_attrmask_next_and(int n, const unsigned long *src1p,
> - const unsigned long *src2p,
> - unsigned int nr_bits)
> -{
> - /* n is a prior cpu */
> - cpu_max_bits_warn(n + 1, nr_bits);
> -
> - if (src1p && src2p)
> - return find_next_and_bit(src1p, src2p, nr_bits, n + 1);
> - else if (src1p)
> - return find_next_bit(src1p, nr_bits, n + 1);
> - else if (src2p)
> - return find_next_bit(src2p, nr_bits, n + 1);
> -
> - return n + 1;
> -}
> #else
> static inline int netif_set_xps_queue(struct net_device *dev,
> const struct cpumask *mask,
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 8049e2ff11a5..b0fb592d51da 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -2592,8 +2592,7 @@ int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
> copy = true;
>
> /* allocate memory for queue storage */
> - for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
> - j < nr_ids;) {
> + for_each_and_bit(j, online_mask, mask ? : online_mask, nr_ids) {
> if (!new_dev_maps) {
> new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
> if (!new_dev_maps)
> --
> 2.34.1