Re: [tip:x86/apic] x86, PCI, ACPI: Kill private function resource_to_addr() in arch/x86/pci/acpi.c

Yinghai Lu
2014-12-11T16:57:26Z

On Thu, Dec 11, 2014 at 8:36 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Wed, 10 Dec 2014, Yinghai Lu wrote:
>> On Wed, Dec 10, 2014 at 12:15 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
>> >> - struct resource r = {
>> >> - .flags = 0
>> >> - };
>> >> + struct resource r;
>> >>
>> >> + memset(&r, 0, sizeof(r));
>> >
>> > What's the point of this change? Both initialize r to 0. memset()
>> > generates better code, but that's irrelevant for the problem at hand.
>
> Did you actually read what I wrote?
>
> struct resource r = {
> .flags = 0
> };
>
> initializes r completely to 0. So how do you get a random pointer in r?

ok, I get it now.

I was thinking that compiler will generate code like
struct resource r;
r.flags = 0;

Thanks

Yinghai