task/schedule: Free init stack during first context switch #593
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Using stack_base + STACK_TOTAL_SIZE is not the correct way to derive a VMKernelStack's top-of-stack address because there are unmapped guard pages on both ends of the stack. Use the output of VMKernelStack::top_of_stack() instead during context switches. Fixes: a448d45 ("schedule: switch to special stack during context switches") Signed-off-by: Peter Fang <[email protected]>
init_stack is now completely unused by the BSP and stops being used by any CPU after switching to the idle task in schedule_init(). Free up these memory pages during context switching. Since a Rust function is called for this purpose, make sure callee-saved registers are used for switch_context's input arguments. Signed-off-by: Peter Fang <[email protected]>
joergroedel
approved these changes
Jan 22, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
init_stackis now completely unused by the BSP and stops being used by any CPU after switching to the idle task inschedule_init(). Free up these memory pages during context switching. Since a Rust function is called for this purpose, make sure callee-saved registers are used forswitch_context's input arguments.