Messages in this thread | | | Date | Thu, 11 Apr 2013 10:58:44 +0800 | From | Simon Jeons <> | Subject | Re: [PATCH] x86: add phys addr validity check for /dev/mem mmap |
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Hi H.Peter, On 04/11/2013 10:48 AM, H. Peter Anvin wrote: > On 04/10/2013 07:40 PM, Simon Jeons wrote: >> Hi H.Peter, >> On 04/04/2013 09:13 AM, H. Peter Anvin wrote: >>> On 04/03/2013 06:11 PM, Simon Jeons wrote: >>>> Why we consider boot_cpu_data.x86_phys_bits instead of e820 map here? >>>> >>> Because x86_phys_bits is what controls how much address space the >>> processor has. e820 tells us how much *RAM* the machine has, or >>> specifically, how much RAM the machine had on boot. >> I have 8GB memory in my machine, but when I accumulated every e820 >> ranges which dump in dmesg, there are 25MB memory less then 8GB(1024*8) >> memory, why 25MB miss? >> > For whatever reason your BIOS is stealing some memory, possibly for video.
Thanks for your quick response. ;-) My machine is new which have i7 cpu. How much memory video need? 8MB? Why I miss 25MB?
> > -hpa > >
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