Re: [PATCH] ring-buffer: Add set/clear_current_oom_origin() during allocations

[Joel Fernandes]

Hi Steve,

On Thu, Apr 5, 2018 at 12:57 PM, Joel Fernandes <joelaf@xxxxxxxxxx> wrote:
> On Thu, Apr 5, 2018 at 6:43 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>> On Wed, 4 Apr 2018 16:59:18 -0700
>> Joel Fernandes <joelaf@xxxxxxxxxx> wrote:
>>
>>> Happy to try anything else, BTW when the si_mem_available check
>>> enabled, this doesn't happen and the buffer_size_kb write fails
>>> normally without hurting anything else.
>>
>> Can you remove the RETRY_MAYFAIL and see if you can try again? It may
>> be that we just remove that, and if si_mem_available() is wrong, it
>> will kill the process :-/ My original code would only add MAYFAIL if it
>> was a kernel thread (which is why I created the mflags variable).
>
> Tried this. Dropping RETRY_MAYFAIL and the si_mem_available check
> destabilized the system and brought it down (along with OOM killing
> the victim).
>
> System hung for several seconds and then both the memory hog and bash
> got killed.

I think its still Ok to keep the OOM patch as a safe guard even though
its hard to test, and the si_mem_available on its own seem sufficient.
What do you think?

thanks,


- Joel