A small patch to discuss, it's about killing an process in an out-of-memory
condition. First from the code I don't see any prohibition that it kills
init, if reaches maximum badness points, don't think thats something anybody
anytime wants. Sure for desktop systems this very unlikely to ever occur, but
for small embedded systems that could happen.
Second proposal is to give processes that are direct childs from init a
special bonus, normally that are those we don't want to get killed. They are
either important or get respawned eitherway creating an endless oom condition
loop when killing them.
A position to think about is to generally bonus processes from their distance
to init. The further down in the hirachy to more unlikely it is for the
process to be important.
Greetings, Axel
diff -ru linux-2.4.20-org/mm/oom_kill.c linux-2.4.20/mm/oom_kill.c
--- linux-2.4.20-org/mm/oom_kill.c Fri Nov 29 00:53:15 2002
+++ linux-2.4.20/mm/oom_kill.c Tue Feb 4 12:10:40 2003
@@ -62,6 +62,11 @@
if (!p->mm)
return 0;
/*
+ * Never kill init
+ */
+ if (p->pid == 1)
+ return 0:
+ /*
* The memory size of the process is the basis for the badness.
*/
points = p->mm->total_vm;
@@ -101,6 +106,15 @@
*/
if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_RAWIO))
points /= 4;
+
+ /*
+ * Give childs from init a bonus, they usually get respawned
+ * eitherway, killing them might not help to solve the out of memory
+ * condition in the long run.
+ */
+ if (p->p_pptr != NULL && p->p_pptr->pid == 1)
+ points /= 4;
+
#ifdef DEBUG
printk(KERN_DEBUG "OOMkill: task %d (%s) got %d points\n",
p->pid, p->comm, points);
-
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This archive was generated by hypermail 2b29 : Fri Feb 07 2003 - 22:00:14 EST