Re: [PATCH 1/2 v2] bcachefs: do not use PF_MEMALLOC_NORECLAIM

Kent Overstreet
2024-09-02T09:51:06Z

On Mon, Sep 02, 2024 at 11:39:41AM GMT, Michal Hocko wrote:
> On Mon 02-09-24 04:52:49, Kent Overstreet wrote:
> > On Mon, Sep 02, 2024 at 10:41:31AM GMT, Michal Hocko wrote:
> > > On Sun 01-09-24 21:35:30, Kent Overstreet wrote:
> > > [...]
> > > > But I am saying that kmalloc(__GFP_NOFAIL) _should_ fail and return NULL
> > > > in the case of bugs, because that's going to be an improvement w.r.t.
> > > > system robustness, in exactly the same way we don't use BUG_ON() if it's
> > > > something that we can't guarantee won't happen in the wild - we WARN()
> > > > and try to handle the error as best we can.
> > >
> > > We have discussed that in a different email thread. And I have to say
> > > that I am not convinced that returning NULL makes a broken code much
> > > better. Why? Because we can expect that broken NOFAIL users will not have a
> > > error checking path. Even valid NOFAIL users will not have one because
> > > they _know_ they do not have a different than retry for ever recovery
> > > path.
> >
> > You mean where I asked you for a link to the discussion and rationale
> > you claimed had happened? Still waiting on that
>
> I am not your assistent to be tasked and search through lore archives.
> Find one if you need that.
>
> Anyway, if you read the email and even tried to understand what is
> written there rather than immediately started shouting a response then
> you would have noticed I have put actual arguments here. You are free to
> disagree with them and lay down your arguments. You have decided to
>
> [...]
>
> > Yeah, enough of this insanity.
>
> so I do not think you are able to do that. Again...

Michal, if you think crashing processes is an acceptable alternative to
error handling _you have no business writing kernel code_.

You have been stridently arguing for one bad idea after another, and
it's an insult to those of us who do give a shit about writing reliable
software.

You're arguing against basic precepts of kernel programming.

Get your head examined. And get the fuck out of here with this shit.