1. Windows 2000 and Solaris: Threads and SMP Management Submitted by: Rahul Bhuman

2. Solaris Processes Process is an abstraction that contains the environment for a user program Each process has a context and various items of state information that define the execution environment of the process A process’s context is further divided into a hardware and software context. Process contain one or more threads Kernel maintains a system wide process table, where by each process is uniquely identified by a positive integer called the process identification number.

3. K er ne l pr oc es s ta bl e Pro ces s Scheduling class and priority Process lineage (parents, children) Signals, handlers, disposition Process state Process ID (PID) Process group ID Parent process ID Open files Credentials (UID, GID) Hardware context (registers, stack) Address space Session information (control terminal, job control state) CPU(s) Memory I/O The basic process environment, minus the thread abstractions below.

4. Windows 2000 Process At the highest level of abstraction, windows 2000 process comprises the following: A private virtual address space An executable program A list of open handles to various system resources that are accessible to all threads in the process. A security context called an access token. A unique identifier called a process ID At least one thread of execution.

5. Structure of Executive Block

6. Kennel Process Block

7. Process Environment Block

8. Solaris Threads User-Level Threads (ULTs) Implemented through a threads library in the address space of a process Invisible to the OS Lightweight processes (LWPs) A mapping between ULTs and kernel threads Each LWP supports one or more ULTs and maps to one kernel thread Scheduled by the kernel independently May execute in parallel on multiprocessors Kernel threads Fundamental entities that can be scheduled and dispatched to run on one of the system processors

9. Unbound user threads are scheduled within the threads library, where the selected user thread is linked to an available LWP. Pr oc es s Software context: open file, credential, address space, process group, session control,… U se r th re ad L W P| Ma chi ne stat e Kt hr ea d CPUCPU Solaris Multithreaded process model

10. Windows 2000 Threads A thread is the entity within a process that Windows 2000 schedules for execution. Thread Includes: The contents of a set of CPU registers representing the state of the processor Two stacks A private storage area called thread-local storage (TLS) A unique identifier called a thread ID Threads sometimes have their own security context

11. Structure of ETHREAD block

12. Kernel Thread BlockThread Environment Block (TEB)

13. Solaris Thread States

14. Windows 2000 Thread States

15. Solaris Thread Scheduling 59 0 +60 -60 +60 interrupt System ints 10 1 Real Time interactive Time Share User Range priority 0 169 -60 Class Priority RangeGlobal Priority Range Scheduling Class 0 - 59000 – 059Time Share and Interactive 0 – 39060 – 099System 0 – 9100 – 109Interrupt Threads if the Real time class is not loaded 0 – 59100 – 159Real Time 0 – 9160 – 169Interrupt threads if the RT class is loaded

16. Windows 2000 Thread Scheduling

17. Windows 2000 Symmetric Multiprocessing

18. Windows 2000 is a symmetric multiprocessing (SMP) operating system. There is no master processor. Windows 2000 incorporates several features that are crucial to its success as a multiprocessor operating system: The ability to run operating system code on any available processor and on multiple processors at the same time Multiple threads of execution within a single process, each of which can execute simultaneously on different processors Fine-grained synchronization within the kernel as well as within device drivers and server processes, which allows more components to run concurrently on multiple processors

19. Solaris Symmetric Multiprocessing 1 2 3 A system interconnect, either bus or cross – bar design. Cache – coherent protocol for data transfers to/from memory, processors, and I/O. Very high, sustainable bandwidth with uniform access times (latency) 1 is CPU (s) 2 is Memory 3 is I/O A Single Multiprocessor system. Shared memory, symmetric system with uniform memory and I/O access. Single kernel image shared by all processes – single address space view.

20. Solaris supports shared memory architecture, which implements a single kernel shared by all the processors and single uniform memory address space. Symmetric Multiprocessor describes a system in which a peer-to- peer relationship exists among all the processors (CPUs) on the system All processors are equal Solaris Symmetric Multiprocessing

21. References Solaris Internals – Core Kernel Architecture Jim Mauro and Richard McDougall Inside Microsoft Windows 2000: Third Edition David A. Solomon and Mark E.Russinovich Operating Systems: Internals and Design Principles William Stallings