From: "Yury Norov (NVIDIA)" <yury.norov@gmail.com>
To: Tony Nguyen <anthony.l.nguyen@intel.com>,
Przemek Kitszel <przemyslaw.kitszel@intel.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: "Yury Norov (NVIDIA)" <yury.norov@gmail.com>
Subject: [PATCH] i40e: drop useless bitmap_weight() call in i40e_set_rxfh_fields()
Date: Mon, 15 Dec 2025 19:28:52 -0500 [thread overview]
Message-ID: <20251216002852.334561-1-yury.norov@gmail.com> (raw)
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) <yury.norov@gmail.com>
---
.../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) {
+ 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
next reply other threads:[~2025-12-16 0:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-16 0:28 Yury Norov (NVIDIA) [this message]
2025-12-17 11:37 ` [Intel-wired-lan] " Loktionov, Aleksandr
2025-12-18 0:29 ` Yury Norov
2025-12-17 22:46 ` kernel test robot
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