{Bp-13444} arm: g_current_regs is only used to determine if we are in irq #13972
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
…other functionalities removed. reason: by doing this we can reduce context switch time, When we exit from an interrupt handler, we directly use tcb->xcp.regs before size nuttx text data bss dec hex filename 225920 409 30925 257254 3ece6 nuttx after text data bss dec hex filename 225604 409 30925 256938 3ebaa nuttx szie change -316 Signed-off-by: hujun5 <hujun5@xiaomi.com>
Signed-off-by: hujun5 <hujun5@xiaomi.com>
Signed-off-by: hujun5 <hujun5@xiaomi.com>
…h other functionalities removed. Signed-off-by: hujun5 <hujun5@xiaomi.com>
github-actions
bot
added
Arch: arm
|
This PR exceeds the recommended size of 1000 lines. Please make sure you are NOT addressing multiple issues with one PR. Note this PR might be rejected due to its size. |
xiaoxiang781216
approved these changes
Oct 9, 2024
|
apache/nuttx-apps#2661 needed |
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Outdated suggestions cannot be applied.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.
Summary
Why
When a context switch occurs currently, the context before the interrupt is fetched from the global variable g_current_regs and then stored in the corresponding tcb->xcp.regs. Subsequently, the new context is assigned to g_current_regs. When returning from the interrupt context, the context is retrieved from g_current_regs and used.
In reality, we do not necessarily require this intermediate variable g_current_regs to accomplish a context switch. Eliminating it avoids multiple assignments, especially during multiple context switches within interrupts, which can lead to repeated assignments.
All we need is to work directly with the context of the currently running task. This approach enhances the speed of context switching, reduces the code base, and optimizes signal handling logic. By simply leveraging the context of the active task, we can streamline the process and improve overall efficiency.
reason:
by doing this we can reduce context switch time,
When we exit from an interrupt handler, we directly use tcb->xcp.regs
Missing Information:
Related Issues: none
NuttX Apps Impact: none
Impact
RELEASE
Testing
CI