| Message ID | 20191119090939.29169-1-vinschen@redhat.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] r8169: disable TSO on a single version of RTL8168c to fix performance | expand |
On 19.11.2019 10:09, Corinna Vinschen wrote: > During performance testing, I found that one of my r8169 NICs suffered > a major performance loss, a 8168c model. > > Running netperf's TCP_STREAM test didn't return the expected > throughput of > 900 Mb/s, but rather only about 22 Mb/s. Strange > enough, running the TCP_MAERTS and UDP_STREAM tests all returned with > throughput > 900 Mb/s, as did TCP_STREAM with the other r8169 NICs I can > test (either one of 8169s, 8168e, 8168f). > > Bisecting turned up commit 93681cd7d94f83903cb3f0f95433d10c28a7e9a5, > "r8169: enable HW csum and TSO" as the culprit. > > I added my 8168c version, RTL_GIGA_MAC_VER_22, to the code > special-casing the 8168evl as per the patch below. This fixed the > performance problem for me. > > Fixes: 93681cd7d94f ("r8169: enable HW csum and TSO") > Signed-off-by: Corinna Vinschen <vinschen@redhat.com> > --- Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
From: Corinna Vinschen <vinschen@redhat.com> Date: Tue, 19 Nov 2019 10:09:39 +0100 > During performance testing, I found that one of my r8169 NICs suffered > a major performance loss, a 8168c model. > > Running netperf's TCP_STREAM test didn't return the expected > throughput of > 900 Mb/s, but rather only about 22 Mb/s. Strange > enough, running the TCP_MAERTS and UDP_STREAM tests all returned with > throughput > 900 Mb/s, as did TCP_STREAM with the other r8169 NICs I can > test (either one of 8169s, 8168e, 8168f). > > Bisecting turned up commit 93681cd7d94f83903cb3f0f95433d10c28a7e9a5, > "r8169: enable HW csum and TSO" as the culprit. > > I added my 8168c version, RTL_GIGA_MAC_VER_22, to the code > special-casing the 8168evl as per the patch below. This fixed the > performance problem for me. > > Fixes: 93681cd7d94f ("r8169: enable HW csum and TSO") > Signed-off-by: Corinna Vinschen <vinschen@redhat.com> Applied, but it would be really nice to know why this is happening instead of just turning it off completely.
On 20.11.2019 01:42, David Miller wrote: > From: Corinna Vinschen <vinschen@redhat.com> > Date: Tue, 19 Nov 2019 10:09:39 +0100 > >> During performance testing, I found that one of my r8169 NICs suffered >> a major performance loss, a 8168c model. >> >> Running netperf's TCP_STREAM test didn't return the expected >> throughput of > 900 Mb/s, but rather only about 22 Mb/s. Strange >> enough, running the TCP_MAERTS and UDP_STREAM tests all returned with >> throughput > 900 Mb/s, as did TCP_STREAM with the other r8169 NICs I can >> test (either one of 8169s, 8168e, 8168f). >> >> Bisecting turned up commit 93681cd7d94f83903cb3f0f95433d10c28a7e9a5, >> "r8169: enable HW csum and TSO" as the culprit. >> >> I added my 8168c version, RTL_GIGA_MAC_VER_22, to the code >> special-casing the 8168evl as per the patch below. This fixed the >> performance problem for me. >> >> Fixes: 93681cd7d94f ("r8169: enable HW csum and TSO") >> Signed-off-by: Corinna Vinschen <vinschen@redhat.com> > > Applied, but it would be really nice to know why this is happening > instead of just turning it off completely. > For RTL8168e-vl Realtek confirmed a HW issue, for this RTL8168c version supposedly it's the same as other chip versions are working fine with TSO.
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index d8fcdb9db8d1..1de11ac05bd6 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -6952,8 +6952,11 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) dev->gso_max_segs = RTL_GSO_MAX_SEGS_V1; } - /* RTL8168e-vl has a HW issue with TSO */ - if (tp->mac_version == RTL_GIGA_MAC_VER_34) { + /* RTL8168e-vl and one RTL8168c variant are known to have a + * HW issue with TSO. + */ + if (tp->mac_version == RTL_GIGA_MAC_VER_34 || + tp->mac_version == RTL_GIGA_MAC_VER_22) { dev->vlan_features &= ~(NETIF_F_ALL_TSO | NETIF_F_SG); dev->hw_features &= ~(NETIF_F_ALL_TSO | NETIF_F_SG); dev->features &= ~(NETIF_F_ALL_TSO | NETIF_F_SG);
During performance testing, I found that one of my r8169 NICs suffered a major performance loss, a 8168c model. Running netperf's TCP_STREAM test didn't return the expected throughput of > 900 Mb/s, but rather only about 22 Mb/s. Strange enough, running the TCP_MAERTS and UDP_STREAM tests all returned with throughput > 900 Mb/s, as did TCP_STREAM with the other r8169 NICs I can test (either one of 8169s, 8168e, 8168f). Bisecting turned up commit 93681cd7d94f83903cb3f0f95433d10c28a7e9a5, "r8169: enable HW csum and TSO" as the culprit. I added my 8168c version, RTL_GIGA_MAC_VER_22, to the code special-casing the 8168evl as per the patch below. This fixed the performance problem for me. Fixes: 93681cd7d94f ("r8169: enable HW csum and TSO") Signed-off-by: Corinna Vinschen <vinschen@redhat.com> --- drivers/net/ethernet/realtek/r8169_main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)