Hello, some private discussion (that was continuing some kernel-summit-discuss thread) ended in the below patch. I also liked a textual "disable" instead of value "-17" (internally to the kernel it could be represented the same way, but the /proc parsing would be more complicated). If you prefer textual "disable" we can change this of course.
Comments welcome. From: Andrea Arcangeli <[EMAIL PROTECTED]> Subject: oom killer protection iscsi/lvm2/multipath needs guaranteed protection from the oom-killer. Signed-off-by: Andrea Arcangeli <[EMAIL PROTECTED]> --- 2.6.12-seccomp/fs/proc/base.c.~1~ 2005-03-25 05:13:28.000000000 +0100 +++ 2.6.12-seccomp/fs/proc/base.c 2005-04-01 23:47:22.000000000 +0200 @@ -751,7 +751,7 @@ static ssize_t oom_adjust_write(struct f if (copy_from_user(buffer, buf, count)) return -EFAULT; oom_adjust = simple_strtol(buffer, &end, 0); - if (oom_adjust < -16 || oom_adjust > 15) + if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE) return -EINVAL; if (*end == '\n') end++; --- 2.6.12-seccomp/include/linux/mm.h.~1~ 2005-03-25 05:13:28.000000000 +0100 +++ 2.6.12-seccomp/include/linux/mm.h 2005-04-01 23:53:11.000000000 +0200 @@ -856,5 +856,8 @@ int in_gate_area_no_task(unsigned long a #define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);}) #endif /* __HAVE_ARCH_GATE_AREA */ +/* /proc/<pid>/oom_adj set to -17 protects from the oom-killer */ +#define OOM_DISABLE -17 + #endif /* __KERNEL__ */ #endif /* _LINUX_MM_H */ --- 2.6.12-seccomp/mm/oom_kill.c.~1~ 2005-03-08 01:02:30.000000000 +0100 +++ 2.6.12-seccomp/mm/oom_kill.c 2005-04-01 23:46:18.000000000 +0200 @@ -145,7 +145,7 @@ static struct task_struct * select_bad_p do_posix_clock_monotonic_gettime(&uptime); do_each_thread(g, p) /* skip the init task with pid == 1 */ - if (p->pid > 1) { + if (p->pid > 1 && p->oomkilladj != OOM_DISABLE) { unsigned long points; /* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/