On Tue, Nov 21, 2000 at 05:28:40PM +0900, [EMAIL PROTECTED] wrote:
> @@ -47,6 +47,11 @@
>                       break;
>               tmp->elevator_sequence--;
>       }
> +     if (entry == head) {
> +             tmp = blkdev_entry_to_request(entry);
> +             if (IN_ORDER(req, tmp))
> +                     entry = real_head->prev;
> +     }
>       list_add(&req->queue, entry);
>  }

This patch is buggy. head with scsi doesn't point to a request so it
doesn't make sense to compare it.

> To implement a complete elevator scheduling, preparing an alternate

Complete elevator scheduling is _just_ implemented, but it's enterely disabled.
You should always enable it before running a 2.4.x kernel. To do that use
elvtune or apply this patch:

--- 2.4.0-test11-pre6/include/linux/elevator.h.~1~      Wed Jul 19 06:43:10 2000
+++ 2.4.0-test11-pre6/include/linux/elevator.h  Tue Nov 21 15:57:51 2000
@@ -100,8 +100,8 @@
 ((elevator_t) {                                                        \
        0,                              /* not used */          \
                                                                \
-       1000000,                                /* read passovers */    \
-       2000000,                                /* write passovers */   \
+       500,                            /* read passovers */    \
+       1000,                           /* write passovers */   \
        0,                              /* max_bomb_segments */ \
                                                                \
        0,                              /* not used */          \


The "DoS" attack is the bug that is been fixed by implementing the new elevator
with proper scheduling.

Andrea
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