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From: "Zhang, Qi Z" <qi.z.zhang@intel.com>
To: Thomas Monjalon <thomas@monjalon.net>,
	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>,
	"Yigit, Ferruh" <ferruh.yigit@intel.com>
Subject: Re: [dpdk-dev] [PATCH] net/i40e: fix counters
Date: Tue, 24 Nov 2020 09:42:58 +0000
Message-ID: <7958eb303ef7422bb1f7bac77b914d49@intel.com> (raw)
In-Reply-To: <2232269.sFVF7DV9YO@thomas>



> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Thomas Monjalon
> Sent: Tuesday, November 24, 2020 4:25 PM
> 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>; Yigit,
> Ferruh <ferruh.yigit@intel.com>
> Subject: Re: [dpdk-dev] [PATCH] net/i40e: fix counters
> 
> I will follow the recommendation of Ferruh and i40e maintainers.
> It is risky but it can be applied just before the release.

I will suggest not to merge this patch in this release cycle, we need time to fully test it and it can always be captured in following LTS release if no issue be found.

Thanks
Qi
> 
> 
> 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  9:43 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
2020-11-24  9:42       ` Zhang, Qi Z [this message]
2020-11-24 10:07         ` Igor Ryzhov
2020-12-23  8:03 ` Zhang, Qi Z

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