Subject: [alpine-devel] switch to segmexec or stay on 2.6.38.2

From: Natanael Copa <[email-masked]>
Date: Mon, 2 May 2011 15:50:16 +0200

Hi,

So, there is a regression in the pageexec feaure we are using in our
kernel config so kernels after 2.6.38.2 does not work (at least not on
the VIA cpu's I have tested)

So, as I understand, we have the following options:
* switch to SEGMEXEC
* stay on 2.6.38.2 (til pageexec is fixed)

I talked with PAX developer on IRC and it will not be fixed anytime
soon, atleast not til the 2.2.0 release tomorrow.

The drawback with SEGMEXEC are:
* not tested in alpine linux and we release tomorrow.
* applications are limited to 1.5GB address space instead of the normal
  3GB.

The benefit with SEGMEXEC is that there are a theoretical performance
increase (i doubt people will notice)

So, with SEGMEXEC people who have an application that uses more than
1.5G will break, even if it used to work. Those should probably switch
to x86_64 anyways.

So what do you guys think: we switch to segmexec now in last minute or
we stay on 2.6.38.2?

-nc

---
Unsubscribe:  [email-masked]
Help:         [email-masked]
---

---

From: Natanael Copa <[email-masked]>
Date: Mon, 2 May 2011 19:29:48 +0200

On Mon, 2 May 2011 15:50:16 +0200

> So what do you guys think: we switch to segmexec now in last minute or

FWIW, I tested to enable both SEGMEXEC and PAGEEXEC. I think this will
make the kernel use SEGMEXEC when cpu has no NX support and PAGEEXEC
otherwise.

This seems to work so far.

Do you think its ok we do this for 2.2.0 release tomorrow?

The kernel is in testing.

-nc

---