On Thu, Feb 23, 2012 at 6:52 AM, 卜弋天 <buyit@xxxxxxx> wrote: > 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. > Thanks ! thats a terse explanation! Can you please mention why we do not have a IRQ stack (in terms of size of the stack) to do the processing? > >> Date: Tue, 21 Feb 2012 19:18:32 -0700 >> Subject: Re: pagetables used in interrupt context >> From: subingangadharan@xxxxxxxxx >> To: dhylands@xxxxxxxxx >> CC: kernelnewbies@xxxxxxxxxxxxxxxxx > >> >> Thank you for clearing my doubt. >> >> On Mon, Feb 20, 2012 at 8:39 PM, Dave Hylands <dhylands@xxxxxxxxx> wrote: >> > Hi Subin, >> > >> > On Mon, Feb 20, 2012 at 6:47 PM, subin gangadharan >> > <subingangadharan@xxxxxxxxx> 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@xxxxxxxxxxxxxxxxx >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
