Hi, Patch to make fork functions faster. Also improve readability of schedule() function. Greetings, Juan PREVIOUS OPERATION AND BUGS 1. Function "kernel/fork.c/find_empty_process()" search for an empty slot in "task" array. It examined every slot in the array and returned the index of the last empty slot, a very inefficient process. It also calculates the amount of empty slots. 2. Function "kernel/fork.c/get_pid()" returns a unique id number. It checked that the id number is unique by looking for it in all slots of the task array, even those marked as unused. It ran through the array using an index. 3. Function "kernel/sched.c/schedule()" used 2 different variables (prev and currentp) to hold the same information. Also, there was an unused variable at the top level of file sched.c. NEW OPERATION 1. A new variable keeps track of the amount of empty slots, modifying its value as slots are taken or released. Another new variable is a pointer to a slot very likely to be empty. The search stops with the first unused slot found, uses and return a pointer to "struct task_struct" instead of an integer index. As result, the new function is faster and more compact. 2. The new get_pid function does not check empty slots, and uses a pointer to "struct task_struct" instead of an integer index. Thus, it is faster and more compact. 3. In file schedule, consolidated the use of two variables with only one, improving readability. Removed unused top level variable. OTHER CHANGES 1. A small optimization to reduce code size was done in files irqtab.c, process.c and printk.c. There is a reduction in code size of 48 bytes. The Image builded without errors. The kernel was tested with QEMU and dioscuri emulators. Also in a PPro pc booting from floppy.
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