From: Kai-Heng Feng <kai.heng.feng@canonical.com>
To: jeffrey.t.kirsher@intel.com
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>,
"David S. Miller" <davem@davemloft.net>,
Sasha Neftin <sasha.neftin@intel.com>,
Dima Ruinskiy <dima.ruinskiy@intel.com>,
Raanan Avargil <raanan.avargil@intel.com>,
intel-wired-lan@lists.osuosl.org (moderated list:INTEL ETHERNET
DRIVERS), netdev@vger.kernel.org (open list:NETWORKING DRIVERS),
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] e1000e: Disable TSO for buffer overrun workaround
Date: Thu, 7 May 2020 22:21:07 +0800 [thread overview]
Message-ID: <20200507142108.13090-1-kai.heng.feng@canonical.com> (raw)
Commit b10effb92e27 ("e1000e: fix buffer overrun while the I219 is
processing DMA transactions") imposes roughly 30% performance penalty.
The commit log states that "Disabling TSO eliminates performance loss
for TCP traffic without a noticeable impact on CPU performance", so
let's disable TSO by default to regain the loss.
Fixes: b10effb92e27 ("e1000e: fix buffer overrun while the I219 is processing DMA transactions")
BugLink: https://bugs.launchpad.net/bugs/1802691
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
drivers/net/ethernet/intel/e1000e/netdev.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 177c6da80c57..9b5509149578 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5294,6 +5294,10 @@ static void e1000_watchdog_task(struct work_struct *work)
/* oops */
break;
}
+ if (hw->mac.type == e1000_pch_spt) {
+ netdev->features &= ~NETIF_F_TSO;
+ netdev->features &= ~NETIF_F_TSO6;
+ }
}
/* enable transmits in the hardware, need to do this
--
2.17.1
next reply other threads:[~2020-05-07 14:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 14:21 Kai-Heng Feng [this message]
2020-05-21 7:18 ` [PATCH] e1000e: Disable TSO for buffer overrun workaround Brown, Aaron F
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