Re: [Xen-devel] [PATCH] xen: drop the nop() macro

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 15.03.19 at 14:41, <wei.liu2@xxxxxxxxxx> wrote:
> On Fri, Mar 15, 2019 at 01:39:05PM +0000, Andrew Cooper wrote:
>> There isn't a plausible reason to insert nops like this into code.
>> 
>> The sole use is in do_debug_key(), and exists to prevent the compiler
>> optimising the tail of the function with 'jmp debugger_trap_fatal'
>> 
>> In practice, a compiler barrier suffices just as well to prevent the 
>> tailcall,
>> and doesn't involve inserting unnecessary instructions.
>> 
>> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> 
> Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>

Acked-by: Jan Beulich <jbeulich@xxxxxxxx>



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