Re: Whether kernel page table is loaded in exception handler?

Re: Whether kernel page table is loaded in exception handler?

[Wang, Baojun]

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On Sunday 28 October 2007 22:58:29, Barisa Kisku wrote：
> Hi,
> Whether kernel page table is loaded during the execution of exception
> handling.I tried to understand that bit code, but could n't find out 
> during the execution of system call exception handling or  external
> interrupt exception handling.
>
>
> thanks in advance.
>
> Barisa Kisku

the external interrupt / syscall exception is not responsible for loading page 
tables. Depending on the type of exception, probably no more exception is 
allowed if the exception have disabled the MSR EE bit. Otherwise it's 
depending on the powerpc model, normally the kernel will search tlb first, if 
there is a (Data/Insn) miss, the kernel will search the page table 
entry(PTEs), if the PTE is founded, the kernel will reload tlb, otherwise it 
will raise a page fault exception, this may ask the kernel to load the page 
on demand, if the kernel could not load the requested the page, then we got a 
double fault (page fault). I'm not sure this is 100% corrent, but help it 
will help

Wang

-- 
Wang, Baojun                                        Lanzhou University
Distributed & Embedded System Lab              http://dslab.lzu.edu.cn
School of Information Science and Engeneering        wangbj@lzu.edu.cn
Tianshui South Road 222. Lanzhou 730000                     .P.R.China
Tel:+86-931-8912025                                Fax:+86-931-8912022

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Re: Whether kernel page table is loaded in exception handler?

[Wang, Baojun]

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On Sunday 28 October 2007 22:58:29, Barisa Kisku wrote：
> Hi,
> Whether kernel page table is loaded during the execution of exception
> handling.I tried to understand that bit code, but could n't find out 
> during the execution of system call exception handling or  external
> interrupt exception handling.
>
>
> thanks in advance.
>
> Barisa Kisku

the external interrupt / syscall exception is not responsible for loading page 
tables. Depending on the type of exception, probably no more exception is 
allowed if the exception have disabled the MSR EE bit. Otherwise it's 
depending on the powerpc model, normally the kernel will search tlb first, if 
there is a (Data/Insn) miss, the kernel will search the page table 
entry(PTEs), if the PTE is founded, the kernel will reload tlb, otherwise it 
will raise a page fault exception, this may ask the kernel to load the page 
on demand, if the kernel could not load the requested the page, then we got a 
double fault (page fault). I'm not sure this is 100% corrent, but help it 
will help

Wang

-- 
Wang, Baojun                                        Lanzhou University
Distributed & Embedded System Lab              http://dslab.lzu.edu.cn
School of Information Science and Engeneering        wangbj@lzu.edu.cn
Tianshui South Road 222. Lanzhou 730000                     .P.R.China
Tel:+86-931-8912025                                Fax:+86-931-8912022

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Whether kernel page table is loaded in exception handler?

[Barisa Kisku]

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Hi,
Whether kernel page table is loaded during the execution of exception
handling.I tried to understand that bit code, but could n't find out  during
the execution of system call exception handling or  external interrupt
exception handling.


thanks in advance.

Barisa Kisku

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