quilt and 2.6.12-ck[1|2]
2.6.12-ck1, the 'Baby Cigar', was out so i just tried it out. But it failed to compile:
kernel/sched.c: In function
inc_nr_running': kernel/sched.c:527: error: structure has no member namedmigration_thread' kernel/sched.c: In functiondec_nr_running': kernel/sched.c:537: error: structure has no member namedmigration_thread' make[2]: [kernel/sched.o] Error 1
make[1]: [kernel] Error 2
UP uses SMP-only stuff. It's easy to fix. A very trivial bug. I think Con might have been too happy/busy having a new baby that he has overlooked this. =)
We can simply add some #ifdef to comment out SMP code for UP. I dont want to mess this trivial fix patch with the 'official' ck patch so i use the quilt tool.
Simply put, quilt is a patch managing tool derived from Andrew Monton's patch scripts. It eases all the patch push/pop work in the process of developing/debugging/fixing/reverting.
Now, back to our case, we create our fix by the following command,
$ quilt new trivialfixsmp.diff
and then edit the file kernel/sched.c to add make some #ifdef,
$ quilt edit kernel/sched.c
and then we refrsesh the patch,
$ quilt refresh
and you'll see the patch at patches/trivialfixsmp.diff
Yeah, i made my patch, compiled the kernel, and found that Con noticed the issue too. And he soon (very soon, if you dont mind) released the ck2. And i found that Con's patch's a little bit different from mine (different patches to do the same thing, anyway). So to use the 'official' fix patch from ck2, we can first remove our patch,
$ quilt pop $ quilt delete trivialfixsmp.diff
and then import Con's patch for this
$ quilt import sched-fix_up_build.patch
and finally apply it,
$ quilt push
Quilt neat. =) For more information, you can read this pdf (it's in the quilt tar ball too).
