LinuxPPC-Dev Archive on lore.kernel.org
 help / color / Atom feed
From: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
To: Lijun Pan <lijunp213@gmail.com>
Cc: netdev@vger.kernel.org, Lijun Pan <ljp@linux.vnet.ibm.com>,
	Tom Falcon <tlfalcon@linux.ibm.com>,
	Paul Mackerras <paulus@samba.org>,
	Dany Madden <drt@linux.ibm.com>, Jakub Kicinski <kuba@kernel.org>,
	linuxppc-dev@lists.ozlabs.org, David Miller <davem@davemloft.net>
Subject: Re: [PATCH V2 net] ibmvnic: Continue with reset if set link down failed
Date: Wed, 21 Apr 2021 23:58:43 -0700
Message-ID: <20210422065843.GA2743610@us.ibm.com> (raw)
In-Reply-To: <CAOhMmr4ckVFTZtSeHFHNgGPUA12xYO8WcUoakx7WdwQfSKBJhA@mail.gmail.com>

Lijun Pan [lijunp213@gmail.com] wrote:
> > Now, sure we can attempt a "thorough hard reset" which also does
> > the same hcalls to reestablish the connection. Is there any
> > other magic in do_hard_reset()? But in addition, it also frees lot
> > more Linux kernel buffers and reallocates them for instance.
> 
> Working around everything in do_reset will make the code very difficult

We are not working around everything. We are doing in do_reset()
exactly what we would do in hard reset for this error (ignore the
set link down error and try to reestablish the connection with the
VIOS).

What we are avoiding is unnecessary work on the Linux side for a
communication problem on the VIOS side.

> to manage. Ultimately do_reset can do anything I am afraid, and do_hard_reset
> can be removed completely or merged into do_reset.
> 
> >
> > If we are having a communication problem with the VIOS, what is
> > the point of freeing and reallocating Linux kernel buffers? Beside
> > being inefficient, it would expose us to even more errors during
> > reset under heavy workloads?
> 
> No real customer runs the system under that heavy load created by
> HTX stress test, which can tear down any working system.

We need to talk to capacity planning and test architects about that,
but all I want to know is what hard reset would do differently to
fix this communication error with VIOS.

Sukadev

  reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-20 21:35 Dany Madden
2021-04-20 21:42 ` Lijun Pan
2021-04-21  6:45   ` Sukadev Bhattiprolu
2021-04-22  5:06     ` Lijun Pan
2021-04-22  6:58       ` Sukadev Bhattiprolu [this message]
2021-04-22  7:05       ` Rick Lindsley
2021-04-22 17:21       ` Michal Suchánek
2021-04-22 17:38         ` Lijun Pan
2021-04-23  2:26         ` Rick Lindsley
2021-05-04 19:05           ` Dany Madden
2021-04-21  7:54   ` Rick Lindsley
2021-04-22  5:12     ` Lijun Pan
2021-04-22  7:05       ` Rick Lindsley
2021-04-22  5:30 ` Lijun Pan
2021-04-22  7:07   ` Rick Lindsley
2021-04-22 17:01     ` Lijun Pan

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=20210422065843.GA2743610@us.ibm.com \
    --to=sukadev@linux.ibm.com \
    --cc=davem@davemloft.net \
    --cc=drt@linux.ibm.com \
    --cc=kuba@kernel.org \
    --cc=lijunp213@gmail.com \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=ljp@linux.vnet.ibm.com \
    --cc=netdev@vger.kernel.org \
    --cc=paulus@samba.org \
    --cc=tlfalcon@linux.ibm.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

LinuxPPC-Dev Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linuxppc-dev/0 linuxppc-dev/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 linuxppc-dev linuxppc-dev/ https://lore.kernel.org/linuxppc-dev \
		linuxppc-dev@lists.ozlabs.org linuxppc-dev@ozlabs.org
	public-inbox-index linuxppc-dev

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.ozlabs.lists.linuxppc-dev


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