Student Information ------------------- Name: Pradyumna Kaushik Directory Contents ------------------ The project should contain the following files, 1. jprobe_fault.c --> The kernel probe to detect page faults. 2. qsort_test.c --> A quick sort program to generate page faults. 3. file_io_test.c --> A program that reads from a file and writes the contents to 2 other files. 4. input_file.txt --> Input file to file_io_test.c. 5. data_output_file.csv --> Data file fetched from kernel module using user space process. This file contains the page fault data for file_io_test.c. 6. data_output_file2.csv --> Data file fetched from kernel module using user space process. This file contains the page fault data for qsort_test.c. 7. data_output_file_graph.xlsx --> Contains scatter plot graphs for both data_output_file.csv and data_output_file2.csv. 8. user.c --> User program to read in data from /proc/data_file and store it in data_output_file.csv or data_output_file2.csv. 9. Makefile --> A makefile to compile the source programs and generate executables. Instructions to compile the programs, run the test programs and insert the module --------------------------------------------------------------------------------- 1. Compile the jprobe_fault.c, qsort_test.c, file_io_test.c, user.c using the following command, make 2. Run any of the test cases (either qsort_test.c or file_io_test.c) using the following commands, Run Quicksort --> ./qsort_test.o Run File IO Test --> ./file_io_test.o Each of these would print the corresponding PID of the process which can be used to insert the kernel module. 3. Insert the kernel module using the following command, sudo insmod jprobe_fault.ko pid=<PID of the process> Now, when page faults occur, the PID and the virtual address, at which the page fault occurred, are printed. 4. Fetch the page fault data, from user process, using the following command, ./user.o This would create a data_output_file.csv file that contains comma separated values corresponding to the PID and virtual address. Note on the Scatter Plot ------------------------ 1. The scatter plot of data_output_file2.csv shows that most of the page faults have occured when the process was loaded into memory. This is due to cold start penalty, where the TLB is flushed out, the cache is emptied and repopulated. So initially, the TLB would not contain any entry for a page. As and when the process faults on a page, the TLB is populated and the process cache is populated. After some amount of time, the cache and the TLB are hot and frequency of page faults reduces.