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

From: Chen, Yu C
Date: Mon Dec 21 2015 - 20:03:53 EST


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?

thanks,
Yu