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Hi Subin:<BR> <BR> 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.<BR> 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.<BR> so the thread which is interrupted by interrupt, it's kernel mode stack will be choosed as the interrupt context of current interrupt.<BR> <BR> <BR><div><div id="SkyDrivePlaceholder"></div>> Date: Tue, 21 Feb 2012 19:18:32 -0700<br>> Subject: Re: pagetables used in interrupt context<br>> From: subingangadharan@gmail.com<br>> To: dhylands@gmail.com<br>> CC: kernelnewbies@kernelnewbies.org<br>> <br>> Thank you for clearing my doubt.<br>> <br>> On Mon, Feb 20, 2012 at 8:39 PM, Dave Hylands <dhylands@gmail.com> wrote:<br>> > Hi Subin,<br>> ><br>> > On Mon, Feb 20, 2012 at 6:47 PM, subin gangadharan<br>> > <subingangadharan@gmail.com> wrote:<br>> >> Hi All,<br>> >><br>> >> Please correct me if I am wrong. In linux each process will have its<br>> >> own page tables, so when a interrupt happens processor will switch to<br>> >> interrupt context<br>> >> and execute the proper handler. So my doubt, if this is the case,<br>> >> interrupt hanlder will be using the pagetables of the interrupted<br>> >> process or is there a separate page table for this.<br>> ><br>> > Yep - that's right. Conceptually you can imagine that the kernel page<br>> > tables are replicated in each process, so when the interrupt occurs,<br>> > the kernel mappings will always be in effect regardless of which task<br>> > is running. How this is actually achieved may vary from architecture<br>> > to architecture.<br>> ><br>> > --<br>> > Dave Hylands<br>> > Shuswap, BC, Canada<br>> > http://www.davehylands.com<br>> <br>> <br>> <br>> -- <br>> With Regards<br>> Subin Gangadharan<br>> <br>> I am not afraid and I am also not afraid of being afraid.<br>> <br>> _______________________________________________<br>> Kernelnewbies mailing list<br>> Kernelnewbies@kernelnewbies.org<br>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies<br></div> </div></body>
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