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Subject: Re: Misleading OOM messages
From: Dave Hansen <dave@linux.vnet.ibm.com>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>, Pavel Machek <pavel@ucw.cz>,
       Andrew Morton <akpm@linux-foundation.org>,
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Date: Fri, 15 May 2009 11:23:27 -0700
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On Fri, 2009-05-15 at 13:58 -0400, Christoph Lameter wrote:
> On Thu, 14 May 2009, David Rientjes wrote:
> > > To me it at least adds the fact that more should be made *available* and
> > > not just that you're out of it.  So, definitely not perfect, but better
> > > than "out".
> > >
> >
> > I think "no allowable memory" followed by information on what is and is
> > not allowed in that specific context would remove any ambiguity.
> 
> Useful information to have. If a NUMA or cgroup restriction caused the
> failure then we should print that out.

We get a wee bit of info out for the cgroups case at least:

void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask)
{
...
        if (oom_kill_process(p, gfp_mask, 0, points, mem,
                                "Memory cgroup out of memory"))
                goto retry;

That can surely be improved, but it's a decent start.

-- Dave