Based On The Research Of Linux Multi-core Process Scheduling

Nowadays, with the rapid development of computer technology, the processormulti-core technology has been enriched and developed, which affects our dailylives.Now, with the rising of the computer hardware performance, the complexity of thecomputer system have gone up, so the operating system must strive to make timely andeffective improvement in order to achieve the purpose of maximizing hardware resourceutilization, and scheduling systems as one of the most important subsystem in theoperating system, its performance is facing severe test. And select what kind ofalgorithm, how the SMP scheduling system load imbalance at a pinch, how to makeadjustments, as well as what kind of adjustments in order to makesoftware andhardware benefit each other, all of them are worth for us to ponder and explore.Firstly the background of this subject is introduced in the dissertation, and anoverview of the process of parallel operation of two technologies: multi-threadingtechnology (Simultaneous Multi-Threading, SMT) and chip multi-processors (ChipMulti-Processor, CMP), and introduces the processe, the thread and the conversion oftheir states, then the basics of common scheduling policy and scheduling algorithm hasbeen learned, besides some of the Linux kernel commonly used data structures andmacro operation, which offer a plenty preparation for the below research.Secondly, regarding the Linux2.6.36kernel as researching target, its currentscheduling system has been analyzed, completely fair scheduling system and SMPscheduling system. In order to have an overall understanding of the scheduling system,the scheduling system from the data structures and important functions of CFS in Linuxkernel have been studied, and the working principle of CFS have been studied.Again, through two key approaches, namely when to check the system load andhow to adjust for the load when imbalance occurs, the implementation of SMP in theLinux kernel has been parsed, and workflows of SMP have been summarized.Andaccording to the SMP analysis, an existing scheduling system model has beenimproved.Finally, using the scheduling model and scheduling principles of analysis,a wake-up-signal based optimization scheme for SMP scheduling system has beenpresented, in order to further enhance the cache hit rate. With FUTEX lock mechanism,the optimization has been designed, and Linux source code has been modified toimplement the optimization scheme, then using the optimization kernel and the standardkernel system were carried out comparison tests, and the results were validated andanalyzed.