xen-devel.lists.xenproject.org archive mirror
 help / color / mirror / Atom feed
From: David Vrabel <david.vrabel@citrix.com>
To: David Sutton <kantras@gmail.com>
Cc: "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: Re: [PATCH 1/2] Revert "xen: properly account for _PAGE_NUMA during xen pte translations"
Date: Tue, 25 Mar 2014 17:13:51 +0000	[thread overview]
Message-ID: <5331B94F.9020601@citrix.com> (raw)
In-Reply-To: <CAPCj91+c8kE8dgp7U3N1ti=XOzFrgcg3Z3S9dYK4AG1tEMqsaA@mail.gmail.com>

On 25/03/14 15:28, David Sutton wrote:
> David,
> 
>> This reverts commit a9c8e4beeeb64c22b84c803747487857fe424b68.
>>
> Please note: this particular patch also helped to resolve an issue
> reported by some of the people using the xen package under Arch Linux,
> where they would see stability issues running certain software
> (particularly firefox) under dom0 - the software would start crashing
> under relatively light usage, with a kernel BUG message.

We are aware that Xen PV guests will not work if CONFIG_NUMA_BALANCING
is enabled with this revert.  But that patch introduced fundamental
breakage to how a guest must read/write non-present page tables entries
which caused even worse breakage.

I suspect that the problematic patch 1667918b6483 ("mm: numa: clear numa
hinting information on mprotect") is not needed on x86 and could be
safely reverted as a temporarily fix.

David

  reply	other threads:[~2014-03-25 17:13 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-25 15:28 [PATCH 1/2] Revert "xen: properly account for _PAGE_NUMA during xen pte translations" David Sutton
2014-03-25 17:13 ` David Vrabel [this message]
2014-03-25 18:19   ` Konrad Rzeszutek Wilk
     [not found]   ` <20140325181939.GA11073@phenom.dumpdata.com>
2014-03-25 18:30     ` David Vrabel
2014-03-25 19:03   ` David Sutton
2014-03-25 19:12     ` David Vrabel
  -- strict thread matches above, loose matches on Subject: below --
2014-03-21 18:18 [RFC PATCH 0/2] x86: fix Xen PV regression caused by NUMA page migration David Vrabel
2014-03-21 18:18 ` [PATCH 1/2] Revert "xen: properly account for _PAGE_NUMA during xen pte translations" David Vrabel

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=5331B94F.9020601@citrix.com \
    --to=david.vrabel@citrix.com \
    --cc=kantras@gmail.com \
    --cc=xen-devel@lists.xen.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).