Re: [PATCH] Prevent OOM from killing init

[Kevin Buhr]

Leif Sawyer <[e-mail]> writes:
> 
> What happens when init is not pid == 1, as is often the case
> during installs, booting off of cdrom, etc..

Well, after spending hours scrutinizing Patrick's one-line patch, I'll
guess that, in these cases, the patch does not prevent init from being
killed by an OOM error.  But, I'll bet that was a rhetorical question.

In any event, whatever process has pid == 1, it can't voluntarily exit
without a panic, and it's the reaper of all orphaned children, so it
makes sense not to kill it.  As Eli points out, the patch is cleaner
if rewritten:

--- xxx/linux-2.4.3-pre6/mm/oom_kill.c  Tue Nov 14 13:56:46 2000
+++ linux-2.4.3-pre6/mm/oom_kill.c      Wed Mar 21 15:25:03 2001
@@ -123,7 +123,7 @@

         read_lock(&tasklist_lock);
         for_each_task(p) {
-               if (p->pid) {
+               if (p->pid > 1) {
                         int points = badness(p);
                         if (points > maxpoints) {
                                 chosen = p;

since no valid pid is ever negative.

I don't see a valid reason for *not* making this change, but I'm
batting zero for two on my last two patch submissions, so I've
probably missed something.

Kevin <[e-mail]>