On Thu, Feb 23, 2012 at 6:52 AM, ??? [off-list ref] 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?

quoted

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

quoted

Thank you for clearing my doubt.

On Mon, Feb 20, 2012 at 8:39 PM, Dave Hylands [off-list ref] wrote:

quoted

Hi Subin,

On Mon, Feb 20, 2012 at 6:47 PM, subin gangadharan
[off-list ref] wrote:

quoted

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

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies at kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies