* [PATCH] e1000e: Disable TSO for buffer overrun workaround
@ 2020-05-07 14:21 Kai-Heng Feng
2020-05-21 7:18 ` Brown, Aaron F
0 siblings, 1 reply; 2+ messages in thread
From: Kai-Heng Feng @ 2020-05-07 14:21 UTC (permalink / raw)
To: jeffrey.t.kirsher
Cc: Kai-Heng Feng, David S. Miller, Sasha Neftin, Dima Ruinskiy,
Raanan Avargil, moderated list:INTEL ETHERNET DRIVERS,
open list:NETWORKING DRIVERS, open list
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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* RE: [PATCH] e1000e: Disable TSO for buffer overrun workaround
2020-05-07 14:21 [PATCH] e1000e: Disable TSO for buffer overrun workaround Kai-Heng Feng
@ 2020-05-21 7:18 ` Brown, Aaron F
0 siblings, 0 replies; 2+ messages in thread
From: Brown, Aaron F @ 2020-05-21 7:18 UTC (permalink / raw)
To: Kai-Heng Feng, Kirsher, Jeffrey T
Cc: David S. Miller, Neftin, Sasha, Dima Ruinskiy, Avargil, Raanan,
moderated list:INTEL ETHERNET DRIVERS,
open list:NETWORKING DRIVERS, open list
> From: netdev-owner@vger.kernel.org <netdev-owner@vger.kernel.org> On
> Behalf Of Kai-Heng Feng
> Sent: Thursday, May 7, 2020 7:21 AM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>
> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>; David S. Miller
> <davem@davemloft.net>; Neftin, Sasha <sasha.neftin@intel.com>; Dima
> Ruinskiy <dima.ruinskiy@intel.com>; Avargil, Raanan
> <raanan.avargil@intel.com>; moderated list:INTEL ETHERNET DRIVERS <intel-
> wired-lan@lists.osuosl.org>; open list:NETWORKING DRIVERS
> <netdev@vger.kernel.org>; open list <linux-kernel@vger.kernel.org>
> Subject: [PATCH] e1000e: Disable TSO for buffer overrun workaround
>
> 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(+)
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
^ permalink raw reply [flat|nested] 2+ messages in thread
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