To give you a deeper understanding of this interesting topic area, in this section, we delve further into it: we summarize the key differences between the standard (or mainline) and RTL kernels.
In the following table, we summarize some of the key differences between the standard (or mainline) and RTL kernels. A primary goal of the RTL project is to ultimately become fully integrated into the regular mainline kernel tree. As this process is evolutionary, the merging of patches from RTL into mainline is slow but steady; interestingly, as you can see from the rightmost column in the following table, most of (around 80% at the time of writing) the RTL work has actually been already merged into the mainline kernel, and it continues to be:
| Component / Feature | Standard or mainline (vanilla) Linux | RTL (fully preemptible / hard real-time Linux) | RT work merged into mainline? |
| Spinlocks | The spinlock critical section is non-preemptible... |
