Messages in this thread | | | Date | Thu, 20 Dec 2007 22:39:06 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 0/5] x86: another attempt at x86 pagetable unification |
| |
* Jeremy Fitzhardinge <jeremy@goop.org> wrote:
> > found a couple of bugs. > > > > firstly, 64-bit wasnt so lucky, you broke > > iounmap()/change_page_attr() > > :-) > > Crap. Worked for me. I'll look into it.
well, there's an easy solution for unification patches: the resulting object files must have _exactly the same_ content as without the unification patches. (Modulo strings as WARN_ON()s referring to include-file names.)
If they differ then the unification did something wrong. With your patchset and the config i sent, the difference is visible in the image size already:
text data bss dec hex filename 7763766 967330 5812328 14543424 ddea40 vmlinux.after 7763811 967330 5812328 14543469 ddea6d vmlinux.before
also, reducing the size and scope of changes helps as well - because that way it can be bisected down to specific changes. Mistakes inevitably happen, especially if you do not enforce a rigid byte-for-byte correctness along the way. You did 5 rather large patches, and it's not testable because your unification steps were too coarse.
In other words: you were asking for trouble and you got it :-)
Ingo
| |