DPDK patches and discussions
 help / color / mirror / Atom feed
From: Ferruh Yigit <ferruh.yigit@intel.com>
To: Dharmik Thakkar <Dharmik.Thakkar@arm.com>,
	Zhou Zhenghua <zhenghuax.zhou@intel.com>
Cc: Wenzhuo Lu <wenzhuo.lu@intel.com>,
	Beilei Xing <beilei.xing@intel.com>,
	Bernard Iremonger <bernard.iremonger@intel.com>,
	dev <dev@dpdk.org>, dpdk stable <stable@dpdk.org>,
	nd <nd@arm.com>
Subject: Re: [dpdk-dev] [dpdk-stable] [PATCH] app/testpmd: don't allow to dynamic change nbcore
Date: Fri, 30 Oct 2020 10:46:31 +0000	[thread overview]
Message-ID: <3707ad7a-9375-4ee7-d275-25dad725edf4@intel.com> (raw)
In-Reply-To: <0507A11B-4C8A-4F7D-83E7-0B9EF42121C1@arm.com>

On 10/29/2020 4:43 AM, Dharmik Thakkar wrote:

<...>

>> On Oct 27, 2020, at 1:42 AM, Zhou Zhenghua <zhenghuax.zhou@intel.com> wrote:
>>
>> When changing the number of forwarding cores in runtime, two issues may be
>> encountered:
>>
>>   - If the setting nbcore little than current nbcore, the forwarding
>>     thread will still running on the extra cores. Therefore, trying to
>>     stop forwarding will hang testpmd, since it will wait for the extra
>>     cores to stop.
>>
>>   - If the setting nbcore greate than actual nbcore, the newly added
>>     cores are not allocated resources.
>>
>> This will face the problem of dynamic resource allocation, so it's not
>> allow to changes nbcore number when forwarding is running.
>>
>> Fixes: 0c0db76f42ed ("app/testpmd: separate forward config setup from display")
>> Cc: bernard.iremonger@intel.com
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Zhou Zhenghua <zhenghuax.zhou@intel.com>
> 
 > Hi Zhou,
 >
 > Although, I see that a few of the configuration options are checking for 
’test_done’, I am wondering if it is truly required.
 > Since, as per the documentation guidelines:
 > 'Configuration changes only become active when forwarding is started/restarted.’
 >
Yes documentation has it and I think that is what happens in below bullet 2 
(increase core count).

But it is easy to reproduce the hung mentioned in the first bullet, I am for 
having this fix.
And this won't contradict with the above document, the config options you can 
set will be taken account when forwarding is started/restarted, but this one 
won't be set because of added check, hence:
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>

@Zhou,
do you have any objection to remove bullet 2 while merging?

  reply	other threads:[~2020-10-30 10:46 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-27  6:42 [dpdk-dev] " Zhou Zhenghua
2020-10-29  4:43 ` Dharmik Thakkar
2020-10-30 10:46   ` Ferruh Yigit [this message]
2020-11-02 15:20     ` [dpdk-dev] [dpdk-stable] " Ferruh Yigit

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=3707ad7a-9375-4ee7-d275-25dad725edf4@intel.com \
    --to=ferruh.yigit@intel.com \
    --cc=Dharmik.Thakkar@arm.com \
    --cc=beilei.xing@intel.com \
    --cc=bernard.iremonger@intel.com \
    --cc=dev@dpdk.org \
    --cc=nd@arm.com \
    --cc=stable@dpdk.org \
    --cc=wenzhuo.lu@intel.com \
    --cc=zhenghuax.zhou@intel.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).