Hi Linus,
This patch actually fixes the starvation bug in sys_wait4() by moving any
process which is serviced for stoppage to the end of the child list.
David
diff -uNr linux-256p1/kernel/exit.c-orig linux-wait-256p1/kernel/exit.c
--- linux-wait-256p1/kernel/exit.c-orig Fri Mar 15 19:05:47 2002
+++ linux-wait-256p1/kernel/exit.c Fri Mar 15 20:54:40 2002
@@ -592,6 +592,12 @@
if (!(options & WUNTRACED) && !(p->ptrace & PT_PTRACED))
continue;
read_unlock(&tasklist_lock);
+
+ /* move to end of parent's list to avoid starvation */
+ write_lock_irq(&tasklist_lock);
+ list_del(&p->sibling);
+ list_add_tail(&p->sibling,&p->parent->children);
+ write_unlock_irq(&tasklist_lock);
retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
if (!retval && stat_addr)
retval = put_user((p->exit_code << 8) | 0x7f, stat_addr);
-
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This archive was generated by hypermail 2b29 : Fri Mar 15 2002 - 22:00:21 EST