lkml.org 
[lkml]   [2021]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [patch 05/12] x86/irq: Provide macro for inlining irq stack switching
Date
On Mon, Feb 08 2021 at 14:42, Josh Poimboeuf wrote:
> On Thu, Feb 04, 2021 at 09:49:08PM +0100, Thomas Gleixner wrote:
>> #ifdef CONFIG_X86_64
>> +
>> +#ifdef CONFIG_UNWINDER_FRAME_POINTER
>> +# define IRQSTACK_CALL_CONSTRAINT , ASM_CALL_CONSTRAINT
>> +#else
>> +# define IRQSTACK_CALL_CONSTRAINT
>> +#endif
>
> Is this really needed? i.e. does ASM_CALL_CONSTRAINT actually affect
> code generation with !FRAME_POINTER?

The problem is that if the asm inline is the first operation in a
function some compilers insert the asm inline before setting up the
frame pointer.

That's actualy irrelevant here as the compiler cannot reorder against
the C code leading to the asm inline. So we can probably replace it with
a big fat comment.

Thanks,

tglx






\
 
 \ /
  Last update: 2021-02-09 16:13    [W:0.146 / U:1.428 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site