In time-sharing systems, context switches are performed rapidly, which makes it seem like multiple processes are being executed simultaneously on the same processor.
42.
L4 added about 5 % 10 % overhead, compared to Mach's 15 %, all the more interesting considering the double context switches needed.
43.
Much of the performance problem normally associated with microkernel systems are due to the context switches as messages are passed back and forth between applications.
44.
In preemptive multitasking, the operating system kernel can also initiate a context switch to satisfy the scheduling policy's priority constraint, thus preempting the active task.
45.
The process must then be repeated to return the results, adding up to a total of four context switches and memory mappings, plus two message verifications.
46.
However, kernel threading may force a context switch between threads at any time, and thus expose race hazards and concurrency bugs that would otherwise lie latent.
47.
When a context switch occurs, the contents of the " working registers " are simply copied into one of a set of registers for this purpose.
48.
The binary incompatibility problem, in addition to the complexity of implementing a full context switch, makes TTAs more suitable for embedded systems than for general purpose computing.
49.
One of those data copies use the CPU . Sending the same file via zero copy reduces the context switches to two and eliminates all CPU data copies.
50.
The implementation of synchronize _ rcu moves the caller of synchronize _ cpu to each CPU, thus blocking until all CPUs have been able to perform the context switch.
