patches for DPDK stable branches
 help / color / mirror / Atom feed
From: Thomas Monjalon <thomas@monjalon.net>
To: Igor Ryzhov <iryzhov@nfware.com>, dev <dev@dpdk.org>,
	"Guo, Jia" <jia.guo@intel.com>
Cc: dpdk stable <stable@dpdk.org>,
	"Xing, Beilei" <beilei.xing@intel.com>,
	ferruh.yigit@intel.com
Subject: Re: [dpdk-stable] [PATCH] net/i40e: fix counters
Date: Tue, 24 Nov 2020 09:24:41 +0100
Message-ID: <2232269.sFVF7DV9YO@thomas> (raw)
In-Reply-To: <2ada7ab1daa242ae8e256b8432141d32@intel.com>

I will follow the recommendation of Ferruh and i40e maintainers.
It is risky but it can be applied just before the release.


24/11/2020 04:34, Guo, Jia:
> hi, igor ryzhov and Thomas
> 
> Since this remain issue is report recently and we need to reproduce the issue and evaluate the patch and guaranty no side affect for other case,
> so I am not sure even I don't think it still have time window to hit 20.11. But whatever we have begin to check your patch for now on. What do you think so?
> 
> 
> From: Igor Ryzhov <iryzhov@nfware.com>
> Sent: Friday, November 20, 2020 2:27 AM
> To: dev <dev@dpdk.org>
> Cc: dpdk stable <stable@dpdk.org>; Xing, Beilei <beilei.xing@intel.com>; Guo, Jia <jia.guo@intel.com>; Thomas Monjalon <thomas@monjalon.net>
> Subject: Re: [PATCH] net/i40e: fix counters
> 
> CC maintainers and Thomas.
> 
> This fix should be 20.11. The issue is seen multiple times a day under ~20G traffic with stats collection once per second.
> 
> Igor
> 
> On Tue, Nov 17, 2020 at 11:56 AM Igor Ryzhov <iryzhov@nfware.com<mailto:iryzhov@nfware.com>> wrote:
> When low and high registers are read separately, this opens the door to
> a race condition:
> - low register is read
> - NIC updates the registers
> - high register is read
> 
> Because of this, we may end up with an incorrect counter value.
> Let's read the registers in one shot, as it is done in Linux kernel
> since the introduction of the i40e driver.
> 
> Fixes: 4861cde46116 ("i40e: new poll mode driver")
> Cc: stable@dpdk.org<mailto:stable@dpdk.org>
> Signed-off-by: Igor Ryzhov <iryzhov@nfware.com<mailto:iryzhov@nfware.com>>
> ---
>  drivers/net/i40e/base/i40e_osdep.h | 10 ++++++++++
>  drivers/net/i40e/i40e_ethdev.c     | 10 +++++++---
>  2 files changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/i40e/base/i40e_osdep.h b/drivers/net/i40e/base/i40e_osdep.h
> index 64b15e1b6138..ebd687240006 100644
> --- a/drivers/net/i40e/base/i40e_osdep.h
> +++ b/drivers/net/i40e/base/i40e_osdep.h
> @@ -133,6 +133,14 @@ static inline uint32_t i40e_read_addr(volatile void *addr)
>         return rte_le_to_cpu_32(I40E_PCI_REG(addr));
>  }
> 
> +#define I40E_PCI_REG64(reg)            rte_read64(reg)
> +#define I40E_PCI_REG64_ADDR(a, reg) \
> +       ((volatile uint64_t *)((char *)(a)->hw_addr + (reg)))
> +static inline uint64_t i40e_read64_addr(volatile void *addr)
> +{
> +       return rte_le_to_cpu_64(I40E_PCI_REG64(addr));
> +}
> +
>  #define I40E_PCI_REG_WRITE(reg, value)         \
>         rte_write32((rte_cpu_to_le_32(value)), reg)
>  #define I40E_PCI_REG_WRITE_RELAXED(reg, value) \
> @@ -145,6 +153,8 @@ static inline uint32_t i40e_read_addr(volatile void *addr)
>  #define I40E_WRITE_REG(hw, reg, value) \
>         I40E_PCI_REG_WRITE(I40E_PCI_REG_ADDR((hw), (reg)), (value))
> 
> +#define I40E_READ_REG64(hw, reg) i40e_read64_addr(I40E_PCI_REG64_ADDR((hw), (reg)))
> +
>  #define rd32(a, reg) i40e_read_addr(I40E_PCI_REG_ADDR((a), (reg)))
>  #define wr32(a, reg, value) \
>         I40E_PCI_REG_WRITE(I40E_PCI_REG_ADDR((a), (reg)), (value))
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index 74f4ac1f9d4e..53b1e9b9e067 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -6451,9 +6451,13 @@ i40e_stat_update_48(struct i40e_hw *hw,
>  {
>         uint64_t new_data;
> 
> -       new_data = (uint64_t)I40E_READ_REG(hw, loreg);
> -       new_data |= ((uint64_t)(I40E_READ_REG(hw, hireg) &
> -                       I40E_16_BIT_MASK)) << I40E_32_BIT_WIDTH;
> +       if (hw->device_id == I40E_DEV_ID_QEMU) {
> +               new_data = (uint64_t)I40E_READ_REG(hw, loreg);
> +               new_data |= ((uint64_t)(I40E_READ_REG(hw, hireg) &
> +                               I40E_16_BIT_MASK)) << I40E_32_BIT_WIDTH;
> +       } else {
> +               new_data = I40E_READ_REG64(hw, loreg);
> +       }
> 
>         if (!offset_loaded)
>                 *offset = new_data;
> --
> 2.29.2
> 






  reply	other threads:[~2020-11-24  8:24 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-17  8:56 Igor Ryzhov
2020-11-19 18:27 ` Igor Ryzhov
2020-11-24  3:34   ` Guo, Jia
2020-11-24  8:24     ` Thomas Monjalon [this message]
2020-11-24  9:42       ` [dpdk-stable] [dpdk-dev] " Zhang, Qi Z
2020-11-24 10:07         ` Igor Ryzhov
2020-12-23  8:03 ` Zhang, Qi Z

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=2232269.sFVF7DV9YO@thomas \
    --to=thomas@monjalon.net \
    --cc=beilei.xing@intel.com \
    --cc=dev@dpdk.org \
    --cc=ferruh.yigit@intel.com \
    --cc=iryzhov@nfware.com \
    --cc=jia.guo@intel.com \
    --cc=stable@dpdk.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

patches for DPDK stable branches

This inbox may be cloned and mirrored by anyone:

	git clone --mirror http://inbox.dpdk.org/stable/0 stable/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 stable stable/ http://inbox.dpdk.org/stable \
		stable@dpdk.org
	public-inbox-index stable

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.stable


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git