DragonFlyBSD

:
:When under heavy load (Opengrok indexing, Hammer daily cleanup and bulk build
:running at the same time), its swap filled entirely
:
:This kernel message was logged on the console:
: swap_pager_getswapspace: failed

Ok, I believe I have fixed the problem.  fork() was causing a
    vm_object leak where old vm_object's were not being properly terminated,
    leaving vm_page's intact and slowly causing swap to fill up.  pkgbox64
    is now running a new kernel.

-Matt
                    Matthew Dillon 
                    <dillon@backplane.com>

On 2011/8/21 05:43 AM, Matthew Dillon wrote:

:
:When under heavy load (Opengrok indexing, Hammer daily cleanup and bulk build
:running at the same time), its swap filled entirely
:
:This kernel message was logged on the console:
: swap_pager_getswapspace: failed

Ok, I believe I have fixed the problem. fork() was causing a
vm_object leak where old vm_object's were not being properly terminated,
leaving vm_page's intact and slowly causing swap to fill up. pkgbox64
is now running a new kernel.

The fix (1f8fc82a) seems to fix my problem I was talking about
on kernel@ the other day, so I jumped in here :), but I started
seeing this occasional warning message on the console under load:

vm_prefault: Warning, backing object race averted lobject 0xffffffe062f5bf20

I also caught a panic in vm_object_deallocate_locked() afterwards:

#15 0xffffffff8052df79 in vm_object_deallocate_locked (
object=0xffffffe06298f420) at /usr/src/sys/vm/vm_object.c:601
601 LIST_REMOVE(object, shadow_list);
(kgdb) l
596 if (temp == object->backing_object)
597 break;
598 vm_object_unlock(temp);
599 }
600 if (temp) {
601 LIST_REMOVE(object, shadow_list);
602 temp->shadow_count--;
603 temp->generation++;
604 object->backing_object = NULL;
605 vm_object_lock_swap();

For my part, I consider the issue resolved

The machine memory consumption has not grown unreasonably even though it has
been under moderate to heavy I/O load for a few days

Swap usage stays just under the vm.swapcache.maxswappct limit

Thanks for the prompt fix!