Re: Fixed PR13146 by not allowing memory allocations to sleep (Was: [SCM] systemtap: system-wide probe/trace tool branch, master, updated. release-1.6-151-g8e794e9)

[Mark Wielaard <mjw at redhat dot com>]

Hi David,

On Thu, 2011-09-01 at 14:39 +0000, dsmith@sourceware.org wrote:
> commit 8e794e9dfeea5a48b84442b92dea6c17b9ef75d1
> Author: David Smith <dsmith@redhat.com>
> Date:   Thu Sep 1 09:39:15 2011 -0500
> 
>     Fixed PR13146 by not allowing memory allocations to sleep.
>     
>     * runtime/alloc.c:  Turn off __GFP_WAIT when allocating memory.
>     * runtime/transport/ring_buffer.c (__stp_alloc_ring_buffer): Ditto.
>     * runtime/counter.c (_stp_counter_init): Handles memory allocation failure
>       better.
>     * runtime/task_finder.c (__stp_call_mmap_callbacks_with_addr): Better
>       cleanup if memory allocation fails.

Sorry for the late reply. But I am suspecting this commit of causing
accasional (though not very frequent) test failures that say:
  ERROR: context (size 8352) allocation failed

I suspect that is caused because the context is one of the larger
allocations at systemtap_module_init time. And because we are no longer
allowed to GFP_WAIT it is more likely to fail now. Would it be
possible/make sense to allow GFP_WAIT for allocations made from context
like systemtap_module_init() that may sleep because they are made from
user context?

Thanks,

Mark