Messages in this thread |  | | Date | Thu, 08 May 2003 14:00:58 +0200 | From | Helge Hafting <> | Subject | Re: top stack (l)users for 2.5.69 |
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Richard B. Johnson wrote: > On Wed, 7 May 2003, Timothy Miller wrote:
>>On typical processors, when one gets an interrupt, the current program >>counter and processor state flags are pushed onto a stack. Which stack >>gets used for this? >> > > > In protected mode, the kernel stack. And, regardless of implimentation > details, there can only be one. It's the one whos stack-selector > is being used by the CPU. So, in the case of Linux, with multiple
A little contradiction there. "There can only be one" versus "the one whos stack-selector is being used by the CPU"
Of course there can only be one stack _at a time_, but the stack selector is switched as part of the context switch - so there is one stack per process.
The same applies to kernel stacks. There can only be one at a time, but the kernel stack pointer is updated on task switches so there is one kernel stack per process too.
> kernel stacks (!?????), one for each process, whatever process is > running in kernel mode (current) has it's SS active. It's the > one that gets hit with the interrupt.
Helge Hafting
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