Re: [nfs-utils RFC PATCH 2/2] gssd: add timeout for upcall threads

From: Olga Kornievskaia <aglo@umich.edu>
To: Steve Dickson <SteveD@redhat.com>
Cc: Scott Mayhew <smayhew@redhat.com>, linux-nfs <linux-nfs@vger.kernel.org>
Subject: Re: [nfs-utils RFC PATCH 2/2] gssd: add timeout for upcall threads
Date: Thu, 27 May 2021 12:47:02 -0400	[thread overview]
Message-ID: <CAN-5tyFG2douMOvKcERHa24hWp7VvgYB9XAN1c84JLsL+81pCA@mail.gmail.com> (raw)
In-Reply-To: <dbb64855-5ca5-0928-eda4-705a9f45c71b@RedHat.com>

On Thu, May 27, 2021 at 8:52 AM Steve Dickson <SteveD@redhat.com> wrote:
>
>
>
> On 5/27/21 7:40 AM, Scott Mayhew wrote:
> > On Wed, 26 May 2021, Steve Dickson wrote:
> >> If people are going to used the -C flag they are saying they want
> >> to ignore hung threads so I'm thinking with printerr(0) we would
> >> be filling up their logs about messages they don't care about.
> >> So I'm thinking we should change this to a printerr(1)
> >
> > Note that message could pop multiple times per thread even without the
> > -C flag because cancellation isn't immediate (a thread needs to hit a
> > cancellation point, which it won't actually do that until it comes back
> > from wherever it's hanging).  My thinking was leaving it with
> > printerr(0) would make it blatantly obvious when something was wrong and
> > needed to be investigated.  I have no issue with changing it to
> > printerr(1) though.
> It would... but I've craft the debugging for a single -v
> is errors only... Maybe I should mention that in the
> man page... And looking at what you mention in the
> man page for -C, it does say it will cause an error
> to be logged... So I guess it makes sense to leave
> it as is.
>
> >
> > Alternatively we could add another flag to struct upcall_thread_info to
> > ensure that message only gets logged once per thread.
> >
> I think it is good as is...
>
> >>
> >> Overall I think the code is very well written with
> >> one exception... The lack of comments. I think it
> >> would be very useful to let the reader know what
> >> you are doing and why.... But by no means is
> >> that a show stopper. Nice work!
> >
> > I can go back and add some comments.
> Well there aren't that many comments to
> begin with.... So you are just following
> the format... ;-)
>
> Don't worry about it... How I will finish my testing
> today... and do the commit with what we got..

Hi Steve,

Can you please provide a bit more time for review to happen?

> Again... Nice work!!

Yes, nice work. But, I object to the current code that sets canceling
threads as default. This way the code hides the problems that occur
instead of forcing people to fix them.

>
> steved.
>