4/14/2023 0 Comments Kernel retrieve timeslice used![]() ![]() The first argument is the inode structure, which is used to retrieve information such as the user ID, group ID, access time, size, the major and minor number of a device, etc. Two arguments are passed in the my_open function. Opening the device is the first operation performed on the device file. This delay provides enough time to capture the behaviour on the screen. The delay mentioned in the above function at Line 25 is used to demonstrate how the code works, with screenshots. ![]() Copy_from_user is used for this data transfer. Here, data is transferred from the user space to the kernel space. The function my_write is similar to read. copy_to_user accepts three arguments-a pointer to the user buffer, a pointer to the kernel buffer and the size of the data to be transferred. When an application program issues the read system call, this function is invoked, and the data is to be copied from the kernel space to the user space using the copy_to_user function. The third is the size of the data to be read, while the fourth is the file pointer position. Four arguments should be passed in the read function-the first and second are pointers to the file structure and user buffer, respectively. A non-negative return value represents the number of bytes successfully read (the return value is a ‘signed size’ type, usually the native integer type for the target platform). The my_read function is used to retrieve data from the device. WithoutLock.c: In the source code, Lines 1 to 9 represent header files. We have used a pre-emptible (low-latency desktop) model as shown in Figure 2. The vanilla kernel offers the following three options for the pre-emptible kernel. This experimental work is done on Ubuntu 16.04 with kernel version 4.15, and a core processor with 8GB RAM. Figure 6: High executes after low completes execution in CS Figure 7: Low process priority gets inherited What if M is a CPU bound process which needs a lot of CPU time? In this case, M keeps on executing and apparently, L is waiting for M to get executed, and indirectly H too is waiting on M.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |