On Fri, 24 Feb 2012, Pekka Enberg wrote:

On Fri, 24 Feb 2012, Josef Bacik wrote:

quoted

quoted

Um well yeah, I'm rewriting a chunk of btrfs which was rapantly leaking memory
so the OOM just couldn't keep up with how much I was sucking down.  This is
strictly a developer is doing something stupid and needs help pointing out what
it is sort of moment, not a day to day OOM.

On Fri, Feb 24, 2012 at 11:45 PM, David Rientjes [off-list ref] wrote:

quoted

If you're debugging new kernel code and you realize that excessive amount
of memory is being consumed so that nothing can even fork, you may want to
try cat /proc/slabinfo before you get into that condition the next time
around, although I already suspect that you know the cache you're leaking.
It doesn't mean we need to add hundreds of lines of code to the kernel.
Try kmemleak.

Kmemleak is a wonderful tool but it's also pretty heavy-weight which
makes it inconvenient in many cases.

Too heavyweight to enable when debugging issues after "rewriting a chunk" 
of a filesystem that manipulates kernel memory?  I can't imagine a better 
time to enable it.