Nogle PSS (principper i samtidighed og parallelitet for operative systemer) forvirringer og tanker

Disse nedenstående ting skete da jeg ville læse igennem til PSS kurset.
  Hvordan er det at file handleren pointer (eller peger) på den rigtige device driver fra fil objektet?
  Når man skal reactivate (enable) interrupts i fetch-loop instructions så kan man bruge bitmasking? (IRET)
  clock algorithm lige så god som LRU
  Forståede ting: brugbare ting med prioitised interrupts. Hvis nu der er flere interrupts så behøves ikke alle blive kaldt via ISR. Dette betyder at den højere prioitet kan få adgang.
  OS'en sørger for at der er ingen andre tråde som har adgang til memory rangen... "datum" = data på entels form.
  I/O manager omkring dataflow: sorting kan være en langsom operation eller unødig f.eks efter en merging af data: http://msdn.microsoft.com/en-us/library/ms141031.aspx
  Omkring device drivers of split-implementation: Top-Half: This is the critical section. The interrupt is disabled when this is executed. Bottom-Half: This is the less critical section. The interrupt is enable when this is executed. http://linuxforthenew.blogspot.dk/2011/07/top-bottom-halfs-in-linux-isr.html
  copy pastes: In computer software, an application binary interface (ABI) describes the low-level interface between a computer program and the operating system or another program.
  ABIs cover details such as:
  the sizes, layout, and alignment of data types the calling convention, which controls how functions' arguments are passed and return values retrieved; for example, whether all parameters are passed on the stack or some are passed in registers, which registers are used for which function parameters, and whether the first function parameter passed on the stack is pushed first or last onto the stack how an application should make system calls to the operating system and, if the ABI specifies direct system calls rather than procedure calls to system call stubs, the system call numbers and in the case of a complete operating system ABI, the binary format of object files, program libraries and so on.
  polling kan bruges sammen med busy waiting: Polling, or polled operation, in computer science, refers to actively sampling the status of an external device by a client program as a synchronous activity. Polling is most often used in terms of input/output (I/O), and is also referred to as polled I/O or software-driven I/O.
  CPU affinity Processor affinity or CPU pinning enables the binding and un-binding of a process or thread to a physical CPU or a range of CPUs, so that the process or thread in question will run only on the CPU or range of CPUs in question, rather than being able to run on any CPU.
 
 
 
 
 
 
  Processes and Threads: thread execution, multi-threading, atomicity, race conditions, mutual exclusion (algorithms, hardwar support), busy waiting vs. blocking Synchronisation and deadlock: mutual exclusion, semaphores, mutexes, monitors, relative time, synchronisation, Co man's conditions, deadlock prevention strategies Deadlock and deadlock handling: deadlock, Co man's conditions, deadlock prevention strategies, livelock, priority inversion PSS2013 (Lecture 12) \The Rest" 15 MAY 2013 3 / 3 Eksamensemner POSIX threads (pthreads) Files and lesystems: basic concepts, name space organisation, meta-data, inodes, hard links, symbolic links, disk block allocation Memory Management: virtual memory, address translation, paging, shared memory, page tables Memory Management: page replacement algorithms and frame allocation I/O, system calls, device drivers: I/O types, system calls (implementation and concepts), device driver (implementation, interfaces, concepts), I/O manager, I/O scheduling, interrupts,