Re: [PATCH v4 7/7] ACPI / x86: introduce acpi_os_readable() support

From: Andy Lutomirski
Date: Tue Dec 22 2015 - 17:49:37 EST


On Mon, Dec 21, 2015 at 5:03 PM, Chen, Yu C <yu.c.chen@xxxxxxxxx> wrote:
> Hi Andy,
> thanks for your review,
>
>> -----Original Message-----
>> From: Andy Lutomirski [mailto:luto@xxxxxxxxxxxxxx]
>> Sent: Friday, December 18, 2015 1:00 AM
>> To: Zheng, Lv
>> Cc: Chen, Yu C; Moore, Robert; Wysocki, Rafael J; Brown, Len; Andy
>> Lutomirski; Lv Zheng; linux-kernel@xxxxxxxxxxxxxxx; Linux ACPI; H. Peter
>> Anvin; Borislav Petkov
>> Subject: Re: [PATCH v4 7/7] ACPI / x86: introduce acpi_os_readable() support
>>
> [cut]
>>
>> I think that hpa or Borislav [cc'd] could address the memory map details
>> better than I could. However, this functionality seems strange.
>>
>> Are these physical addresses or virtual addresses that are being dumped?
> [Yu] They are virtual addresses to be dumped.
>> In either case, ISTM that using something iike page_is_ram might be a lot
>> simpler.
> [Yu] if i understand correctly, this API is used to check if the address is a valid
> 'kmalloc' style address, but not 'kmap' or 'vmalloc' address, and page_is_ram
> might treat the latter as valid address?
>

I'm a bit puzzled as to why this matters, but I have no fundamental
objection to doing it that way.

What's the use case, though? That is, what goes wrong if the function
just always returns false?

--Andy

> thanks,
> Yu



--
Andy Lutomirski
AMA Capital Management, LLC
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/