On Thu, 03 Jan 2008 12:13:32 -0500 Lee Schermerhorn <[EMAIL PROTECTED]> wrote:
> Yes, but the problem, when it occurs, is very awkward. The system just > hangs for hours/days spinning on the reverse mapping locks--in both > page_referenced() and try_to_unmap(). No pages get reclaimed and NO OOM > kill occurs because we never get that far. So, I'm not sure I'd call > any OOM kills resulting from this patch as "false". The memory is > effectively nonreclaimable. Now, I think that your anon pages SEQ > patch will eliminate the contention in page_referenced[_anon](), but we > could still hang in try_to_unmap(). I am hoping that Nick's ticket spinlocks will fix this problem. Would you happen to have any test cases for the above problem that I could use to reproduce the problem and look for an automatic fix? Any fix that requires the sysadmin to tune things _just_ right seems too dangerous to me - especially if a change in the workload can result in the system doing exactly the wrong thing... The idea is valid, but it just has to work automagically. Btw, if page_referenced() is called less, the locks that try_to_unmap() also takes should get less contention. -- All Rights Reversed -- 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/
