From: Shrikrishna Khare <skhare@shri-linux.eng.vmware.com>
To: Nachi Prachanda <nprachan@Brocade.com>
Cc: Chas Williams III <ciwillia@Brocade.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"skhare@vmware.com" <skhare@vmware.com>
Subject: Re: [dpdk-dev] [PATCH 1/6] net/vmxnet3: retain counters on restart
Date: Thu, 25 May 2017 13:27:23 -0700 [thread overview]
Message-ID: <alpine.DEB.2.10.1705251319360.5989@shri-linux.eng.vmware.com> (raw)
In-Reply-To: <6c785a5767ff466293523fbc88c901f0@Hq1wp-exmb11.corp.brocade.com>
On Thu, 25 May 2017, Nachi Prachanda wrote:
> > From: Shrikrishna Khare [mailto:skhare@shri-linux.eng.vmware.com]
> > Sent: Wednesday, May 24, 2017 2:10 PM
> >
> > On Fri, 19 May 2017, Charles (Chas) Williams wrote:
> >
> > > From: Nachiketa Prachanda <nprachan@brocade.com>
> > >
> > > Most nics like virtio, igb/ixgbe etc. don't reset counters on
> > > dev_start and arguably this helps in monitoring the counters across a
> > > longer time span with multiple device start/stops.
> > > vmxnet3 behavior is opposite to that and counters are reset by the
> > > host side implementation each time the device is restarted.
> > >
> > > Change the driver to save the counters in its private context before
> > > it is reset by writing CMD_ACTIVATE to REG_CMD.
> > >
> > > Signed-off-by: Nachiketa Prachanda <nprachan@brocade.com>
> >
> > This won't be able to deal with vMotion or suspend/resume?
>
> Correct - this can't deal with the VM suspend/resume unless hypervisor maintains the counter. But this patch doesn't make that behavior any worse than what it was before.
The current code always resets stats, but am concerned that this patch
will make the behavior inconsistent for cases like suspend/resume.
Wondering if this will be better handled by the device emulation instead
of the driver (for igb/ixgbe, is this handled by the hardware?).
If we were to handle this in the device emulation, what would be the
goals/requirements:
- device start/stop should not reset stats?
- any other operations where we would like to maintain/reset stats?
- what might be the expectation around how accurate the stats need to be?
- any other requirement on the device?
Also, note that if we proceed with this patch, and later extend device
support to not reset stats, driver with this patch running on the extended
device will report incorrect stats.
Thanks,
Shri
next prev parent reply other threads:[~2017-05-25 20:27 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-19 17:55 Charles (Chas) Williams
2017-05-19 17:55 ` [dpdk-dev] [PATCH 2/6] net/vmxnet3: Implement retrieval of extended stats Charles (Chas) Williams
2017-05-24 0:17 ` Shrikrishna Khare
2017-05-19 17:55 ` [dpdk-dev] [PATCH 3/6] net/vmxnet3: Generate link-state change notifications Charles (Chas) Williams
2017-05-19 17:55 ` [dpdk-dev] [PATCH 4/6] net/vmxnet3: Make vmxnet3_process_events less noisy Charles (Chas) Williams
2017-05-23 21:44 ` Shrikrishna Khare
2017-05-19 17:55 ` [dpdk-dev] [PATCH 5/6] net/vmxnet3: receive queue lockup and memleak Charles (Chas) Williams
2017-06-01 12:24 ` Charles (Chas) Williams
2017-05-24 21:09 ` [dpdk-dev] [PATCH 1/6] net/vmxnet3: retain counters on restart Shrikrishna Khare
2017-05-25 18:31 ` Nachi Prachanda
2017-05-25 20:27 ` Shrikrishna Khare [this message]
2017-05-25 22:08 ` Nachi Prachanda
2017-05-26 17:29 ` Shrikrishna Khare
2017-05-26 19:01 ` Nachi Prachanda
2017-05-26 17:31 ` Shrikrishna Khare
2017-06-15 12:16 ` [dpdk-dev] [PATCH V2 0/6] some local vmxnet3 patches Charles (Chas) Williams
2017-06-15 12:16 ` [dpdk-dev] [PATCH v2 1/6] net/vmxnet3: retain counters on restart Charles (Chas) Williams
2017-06-15 12:16 ` [dpdk-dev] [PATCH v2 2/6] net/vmxnet3: Implement retrieval of extended stats Charles (Chas) Williams
2017-06-21 1:42 ` Shrikrishna Khare
2017-06-15 12:16 ` [dpdk-dev] [PATCH v2 3/6] net/vmxnet3: Generate link-state change notifications Charles (Chas) Williams
2017-06-27 13:52 ` Ferruh Yigit
2017-06-15 12:16 ` [dpdk-dev] [PATCH v2 4/6] net/vmxnet3: Make vmxnet3_process_events less noisy Charles (Chas) Williams
2017-06-28 11:30 ` [dpdk-dev] [PATCH V2 0/6] some local vmxnet3 patches Ferruh Yigit
2017-06-28 12:52 ` Ferruh Yigit
2017-06-28 13:09 ` Charles (Chas) Williams
2017-06-28 17:15 ` Charles (Chas) Williams
2017-06-28 17:54 ` Ferruh Yigit
2017-06-15 12:17 ` [dpdk-dev] [PATCH v2 5/6] net/vmxnet3: receive queue memory leak Charles (Chas) Williams
2017-06-23 23:00 ` Shrikrishna Khare
2017-06-15 12:17 ` [dpdk-dev] [PATCH v2 6/6] net/vmxnet3: preserve configured MAC address Charles (Chas) Williams
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