Re: [PATCH] mm: warn about allocations which stall for too long

[Dave Hansen]

On 09/23/2016 01:15 AM, Michal Hocko wrote:
> +     /* Make sure we know about allocations which stall for too long */
> +     if (!(gfp_mask & __GFP_NOWARN) && time_after(jiffies, alloc_start + 
> stall_timeout)) {
> +             pr_warn("%s: page alloction stalls for %ums: order:%u 
> mode:%#x(%pGg)\n",
> +                             current->comm, 
> jiffies_to_msecs(jiffies-alloc_start),
> +                             order, gfp_mask, &gfp_mask);
> +             stall_timeout += 10 * HZ;
> +             dump_stack();
> +     }

This would make an awesome tracepoint.  There's probably still plenty of
value to having it in dmesg, but the configurability of tracepoints is
hard to beat.