> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf
> Of Yury Norov (NVIDIA)
> Sent: Tuesday, December 16, 2025 1:29 AM
> To: Nguyen, Anthony L <[email protected]>; Kitszel,
> Przemyslaw <[email protected]>; Andrew Lunn
> <[email protected]>; David S. Miller <[email protected]>; Eric
> Dumazet <[email protected]>; Jakub Kicinski <[email protected]>; Paolo
> Abeni <[email protected]>; [email protected];
> [email protected]; [email protected]
> Cc: Yury Norov (NVIDIA) <[email protected]>
> Subject: [Intel-wired-lan] [PATCH] i40e: drop useless bitmap_weight()
> call in i40e_set_rxfh_fields()
>
> bitmap_weight() is O(N) and useless here, because the following
> for_each_set_bit() returns immediately in case of empty flow_pctypes.
>
> Signed-off-by: Yury Norov (NVIDIA) <[email protected]>
> ---
> .../net/ethernet/intel/i40e/i40e_ethtool.c | 24 ++++++++----------
> -
> 1 file changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> index f2c2646ea298..54b0348fdee3 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
> @@ -3720,20 +3720,16 @@ static int i40e_set_rxfh_fields(struct
> net_device *netdev,
> return -EINVAL;
> }
>
> - if (bitmap_weight(flow_pctypes, FLOW_PCTYPES_SIZE)) {
> - u8 flow_id;
> -
> - for_each_set_bit(flow_id, flow_pctypes,
> FLOW_PCTYPES_SIZE) {
> - i_setc = (u64)i40e_read_rx_ctl(hw,
> I40E_GLQF_HASH_INSET(0, flow_id)) |
> - ((u64)i40e_read_rx_ctl(hw,
> I40E_GLQF_HASH_INSET(1, flow_id)) << 32);
> - i_set = i40e_get_rss_hash_bits(&pf->hw, nfc,
> i_setc);
> -
> - i40e_write_rx_ctl(hw, I40E_GLQF_HASH_INSET(0,
> flow_id),
> - (u32)i_set);
> - i40e_write_rx_ctl(hw, I40E_GLQF_HASH_INSET(1,
> flow_id),
> - (u32)(i_set >> 32));
> - hena |= BIT_ULL(flow_id);
> - }
> + for_each_set_bit(flow_id, flow_pctypes, FLOW_PCTYPES_SIZE) {
You removed the flow_id declaration, but use it in the code below.
Are you sure it compiles?
> + i_setc = (u64)i40e_read_rx_ctl(hw,
> I40E_GLQF_HASH_INSET(0, flow_id)) |
> + ((u64)i40e_read_rx_ctl(hw,
> I40E_GLQF_HASH_INSET(1, flow_id)) << 32);
> + i_set = i40e_get_rss_hash_bits(&pf->hw, nfc, i_setc);
> +
> + i40e_write_rx_ctl(hw, I40E_GLQF_HASH_INSET(0, flow_id),
> + (u32)i_set);
> + i40e_write_rx_ctl(hw, I40E_GLQF_HASH_INSET(1, flow_id),
> + (u32)(i_set >> 32));
> + hena |= BIT_ULL(flow_id);
> }
>
> i40e_write_rx_ctl(hw, I40E_PFQF_HENA(0), (u32)hena);
> --
> 2.43.0
