Re: [PATCH] perf core: Get rid of 'uses dynamic stack allocation' warning

From: Peter Zijlstra
Date: Fri Jan 22 2016 - 03:00:22 EST

On Fri, Jan 22, 2016 at 06:52:01AM +0000, Wang Nan wrote:
> On s390 with CONFIG_WARN_DYNAMIC_STACK set, 'uses dynamic stack
> allocation' warning is issued when defining 'struct perf_sample_data'
> local variable.
> This patch suppress this warning by allocating extra 255 bytes and
> compute aligned pointer manually.

I've seen the warning and always wondered wtf it was about. This
Changelog doesn't actually explain what the problem is, so I cannot
judge the solution.

That said, 255 extra bytes does sound excessive just to avoid a warn.