{Bp-13444} arm: g_current_regs is only used to determine if we are in irq#13972
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…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>
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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
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Oct 9, 2024
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apache/nuttx-apps#2661 needed |
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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
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