Hi, Please cc your reply to my email. many thanks I would appreciate any help on the following questions.
I have looked on disk scheduling algorithms <http://www.cs.princeton.edu/courses/archive/fall06/cos318/lectures/disks.pdf> and the main thing that striked me is that most of the algorithms that i have read in the textbooks (some are explained in the previous ) don't take into consideration the "priority of the process". Being the short seek time first, scan, or c-scan algorithm, all are explained through a string of block numbers, but no mention is given about the owner of these blocks.does it mean all the processes are treated equally?? In my opinion a sort of Multi level queue like with CPU scheduling algorithm can be used to schedule the processes according to their importance. any comment? My second question is about the implementation, i.e. how the different requests are actually aligned in the disk queue? if a process submit a disk I/O request, its PCB should be linked to the disk queue. My question is, in making the system call, and after checking the permission rights and identifying the sought data (block) address in the disk and the target address in the memory does the kernel store this information in the pcb, then link this pcb in the disk queue? By doing so and once the disk controller is free , the device driver checks the queue pcbs and read the requested blocks and depending on the current location of the disk head and the queue pcb block request, the driver orders the controller to process a certain block request of a certain process. The driver removes this request from the pcb content is that how it is implemented? Many thanks ____________________________________________________________________________________ Yahoo! Music Unlimited Access over 1 million songs. http://music.yahoo.com/unlimited - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/