From: "Verma, Vishal L" <vishal.l.verma@intel.com>
To: "david@redhat.com" <david@redhat.com>,
"mhocko@kernel.org" <mhocko@kernel.org>
Cc: "Williams, Dan J" <dan.j.williams@intel.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>
Subject: Re: [PATCH v3] mm/memory_hotplug: refrain from adding memory into an impossible node
Date: Thu, 16 Apr 2020 16:18:37 +0000 [thread overview]
Message-ID: <f3e3efff8f9584c42bd0145d94cb6f37a5461e6f.camel@intel.com> (raw)
In-Reply-To: <16b04f11-f0d7-08e0-ac8c-72b1bd66f1c3@redhat.com>
On Thu, 2020-04-16 at 18:16 +0200, David Hildenbrand wrote:
> > >
> > > Doing that papers over something that is clearly a FW issue and makes
> > > it "my performance is suboptimal" deal with it OS problem. Really, is
> > > this something we have to care about. Your changelog talks about a Qemu
> > > misconfiguration which is trivial to fix. Has this ever been observed
> > > with a real HW?
> > >
> > Well - more of a qemu bug I think - I can share the details, but it just
> > looked like it was producing a bogus SRAT. I think it is plausible that
> > such a firmware bug can happen out in the wild. The NFIT tables would
> > just need to reference a 'proximity domain' that the SRAT hasn't
> > previously described, and hotplug will happily go add memory from the
> > NFIT and the backing node related data structures would be missing.
> >
> > I'm not too opposed to erroring out, so long as we are ok with the fact
> > that we will leave some memory stranded until there's a firmware fix.
>
> So let's reject it and print a warning, so we know it's a thing. If this
> actually shows up often in real live, we have good evidence that we
> should tolerate buggy firmwares instead of warning/rejecting.
>
> (rejecting from inside add_memory() still makes sense IMHO)
>
Sounds good, I'll send a v4.
prev parent reply other threads:[~2020-04-16 16:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-14 23:58 [PATCH v3] mm/memory_hotplug: refrain from adding memory into an impossible node Vishal Verma
2020-04-15 7:39 ` David Hildenbrand
2020-04-15 7:44 ` David Hildenbrand
2020-04-15 10:43 ` Michal Hocko
2020-04-15 20:32 ` Verma, Vishal L
2020-04-16 6:19 ` Michal Hocko
2020-04-16 16:13 ` Verma, Vishal L
2020-04-16 16:16 ` David Hildenbrand
2020-04-16 16:18 ` Verma, Vishal L [this message]
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=f3e3efff8f9584c42bd0145d94cb6f37a5461e6f.camel@intel.com \
--to=vishal.l.verma@intel.com \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=david@redhat.com \
--cc=linux-mm@kvack.org \
--cc=linux-nvdimm@lists.01.org \
--cc=mhocko@kernel.org \
/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).