lkml.org 
[lkml]   [2014]   [May]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC 2/2] x86_64: expand kernel stack to 16K
    On Fri, May 30, 2014 at 10:21:13AM +1000, Dave Chinner wrote:
    > On Thu, May 29, 2014 at 08:06:49PM -0400, Dave Jones wrote:
    > > On Fri, May 30, 2014 at 09:53:08AM +1000, Dave Chinner wrote:
    > >
    > > > That sounds like a plan. Perhaps it would be useful to add a
    > > > WARN_ON_ONCE(stack_usage > 8k) (or some other arbitrary depth beyond
    > > > 8k) so that we get some indication that we're hitting a deep stack
    > > > but the system otherwise keeps functioning. That gives us some
    > > > motivation to keep stack usage down but isn't a fatal problem like
    > > > it is now....
    > >
    > > We have check_stack_usage() and DEBUG_STACK_USAGE for this.
    > > Though it needs some tweaking if we move to 16K
    >
    > Right, but it doesn't throw loud warnings when a specific threshold
    > is reached - it just issues a quiet message when a process exits
    > telling you what the maximum was without giving us a stack to chew
    > on....

    But we could enhance the inform so notice the risk to the user.
    as follow

    ...
    "kworker/u24:1 (94) used greatest stack depth: 8K bytes left, it means
    there is some horrible stack hogger in your kernel. Please report it
    the LKML and enable stacktrace to investigate who is culprit"


    >
    > Cheers,
    >
    > Dave.
    > --
    > Dave Chinner
    > david@fromorbit.com
    >
    > --
    > To unsubscribe, send a message with 'unsubscribe linux-mm' in
    > the body to majordomo@kvack.org. For more info on Linux MM,
    > see: http://www.linux-mm.org/ .
    > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

    --
    Kind regards,
    Minchan Kim


    \
     
     \ /
      Last update: 2014-05-30 03:21    [W:4.033 / U:0.180 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site