pagetables used in interrupt context

[卜弋天]

Hi Subin:     for kernel version 2.6.35, ARM architecture, when interrupt occurs, kernel will change from USER/SVC mode to IRQ mode,backup some registers and change to SVC mode immediately, handle the real interrupt handler in SVC mode, which people say in interrupt context.    kernel will use the stack(interrupt context) of interrupted thread to handle the interrupt, and there is no MMU operation which do page table switch.    so the thread which is interrupted by interrupt, it's kernel mode stack will be choosed as the interrupt context of current interrupt.  > Date: Tue, 21 Feb 2012 19:18:32 -0700
> Subject: Re: pagetables used in interrupt context
> From: subingangadharan at gmail.com
> To: dhylands at gmail.com
> CC: kernelnewbies at kernelnewbies.org
> 
> Thank you for clearing my doubt.
> 
> On Mon, Feb 20, 2012 at 8:39 PM, Dave Hylands <dhylands at gmail.com> wrote:
> > Hi Subin,
> >
> > On Mon, Feb 20, 2012 at 6:47 PM, subin gangadharan
> > <subingangadharan at gmail.com> wrote:
> >> Hi All,
> >>
> >> Please correct me if I am wrong. In linux each process will have its
> >> own page tables, so when a interrupt happens processor will switch to
> >> interrupt context
> >> and execute the proper handler. So my doubt, if this is the case,
> >> interrupt hanlder will be using the pagetables of the interrupted
> >> process or is there a separate page table for this.
> >
> > Yep - that's right. Conceptually you can imagine that the kernel page
> > tables are replicated in each process, so when the interrupt occurs,
> > the kernel mappings will always be in effect regardless of which task
> > is running. How this is actually achieved may vary from architecture
> > to architecture.
> >
> > --
> > Dave Hylands
> > Shuswap, BC, Canada
> > http://www.davehylands.com
> 
> 
> 
> -- 
> With Regards
> Subin Gangadharan
> 
> I am not afraid and I am also not afraid of being afraid.
> 
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20120223/253c11e6/attachment.html