Dear Experts:
I have some questions about the linux timers: Dear Experts: I have some questions about the linux timers: 1. If one linux platform does not enable CONFIG_HIGH_RES_TIMERS, it means the platform does not support high resulution timer, what is the side effect? Is there any exact examples that can let me know the necessary of hrtimer? For example, if hrtimer is not enabled in code, the video 1080P will not work? I need these kind of examples to judge whether to enable hrtimer. Dear Experts: I have some questions about the linux timers: 1. Suppose in one linux platform, the timer HW is far from CPU core, if CPU wants to access timer register, it needs to go through several bus(AXI, AHB, APB), finally the access arrives at timer register, in this example, if I enable CONFIG_TICK_ONESHOT, and if the HZ == 512, it means CPU core needs to call function set_next_event 512 times per second, and the access latency caused by HW design will be large, how to mitigate this? Dear Experts: I have some questions about the linux timers: 1. Suppose in one linux platform, the system counter HW is far from CPU core, if CPU wants to access system counter, it needs to go though several bus(AXI, AHB, APB), fianally the access arrives at counter register, as far as I know, kernel will call update_wall_time based on HZ, suppose HZ == 512, it means the update_wall_time will be called 512 times per second. And inside function update_wall_time, it will read system counter register. So the access latency caused by system counter HW design will be large, how to mitigate this? Thanks in advance.
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