Re: [RFC 2/2] x86_64: expand kernel stack to 16K

H. Peter Anvin
2014-05-30T15:28:40Z

On 05/29/2014 06:34 PM, Dave Chinner wrote:
>> ...
>> "kworker/u24:1 (94) used greatest stack depth: 8K bytes left, it means
>> there is some horrible stack hogger in your kernel. Please report it
>> the LKML and enable stacktrace to investigate who is culprit"
>
> That, however, presumes that a user can reproduce the problem on
> demand. Experience tells me that this is the exception rather than
> the norm for production systems, and so capturing the stack in real
> time is IMO the only useful thing we could add...
>

If we removed struct thread_info from the stack allocation then one
could do a guard page below the stack. Of course, we'd have to use IST
for #PF in that case, which makes it a non-production option.

-hpa