All of lore.kernel.org
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Joerg Roedel <jroedel@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Meelis Roos <mroos@linux.ee>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-mm <linux-mm@kvack.org>,
	Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: 32-bit PTI with THP = userspace corruption
Date: Tue, 11 Sep 2018 08:20:33 -1000	[thread overview]
Message-ID: <CA+55aFzo3b2aChbJ2aOSvKbguYKMG8wv02NS8qzp6w2T5z8WTg@mail.gmail.com> (raw)
In-Reply-To: <20180911114927.gikd3uf3otxn2ekq@suse.de>

On Tue, Sep 11, 2018 at 1:49 AM Joerg Roedel <jroedel@suse.de> wrote:
>
> I had a look into the THP and the HugeTLBfs code, and that is not
> really easy to fix there. As I can see it now, there are a few options
> to fix that, but most of them are ugly:

Just do (4): disable PTI with PAE.

Then we can try to make people perhaps not use !PAE very much, and
warn if you have PAE disabled on a machine that supports it.

As you say, there shouldn't be much of a performance impact from PAE.
There is a more noticeable performance impact from HIGHMEM, not from
HIGHMEM_64G, iirc.

                Linus

  parent reply	other threads:[~2018-09-11 18:20 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-30 18:09 32-bit PTI with THP = userspace corruption Meelis Roos
2018-08-30 20:55 ` Joerg Roedel
2018-08-31  4:12   ` Meelis Roos
2018-08-31  7:07     ` Joerg Roedel
2018-09-08 10:24       ` Thomas Gleixner
2018-09-11 11:49         ` Joerg Roedel
2018-09-11 11:58           ` Meelis Roos
2018-09-11 12:12             ` Joerg Roedel
2018-09-18 13:00               ` Alan Cox
2018-10-21 12:37                 ` Pavel Machek
2018-10-22  7:56                   ` Joerg Roedel
2018-10-22 18:48                     ` Alan Cox
2018-10-23  9:11                       ` Not-so-old machines without PAE was " Pavel Machek
2018-10-22 20:56                     ` Pavel Machek
2018-09-11 18:20           ` Linus Torvalds [this message]
2018-08-31  7:10   ` Meelis Roos

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=CA+55aFzo3b2aChbJ2aOSvKbguYKMG8wv02NS8qzp6w2T5z8WTg@mail.gmail.com \
    --to=torvalds@linux-foundation.org \
    --cc=aarcange@redhat.com \
    --cc=jroedel@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mroos@linux.ee \
    --cc=tglx@linutronix.de \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.