devmmap_paging

OS-II Kernel Programming Assignment

CS18BTECH11042
CS18BTECH11050

LIST OF FILES SUBMITTED

mykmod_main.c
memutil.cpp
README.md
Report.pdf

COMPILATION INSTRUCTIONS

BUILDING AND LOADING THE DRIVER

[root@cs3523 ~]# cd devmmap_paging
[root@cs3523 devmmap_paging]# make
make[1]: Entering directory `/root/devmmap_paging/kernel'
make -C /lib/modules/3.10.0-1062.9.1.el7.x86_64/build M=/root/devmmap_paging/kernel modules
make[2]: Entering directory `/usr/src/kernels/3.10.0-1062.9.1.el7.x86_64'
  CC [M]  /root/devmmap_paging/kernel/mykmod_main.o
/root/devmmap_paging/kernel/mykmod_main.c:19:0: warning: "PAGE_SIZE" redefined [enabled by default]
 #define PAGE_SIZE 4096
 ^
In file included from ./arch/x86/include/asm/ptrace.h:5:0,
                 from ./arch/x86/include/asm/alternative.h:10,
                 from ./arch/x86/include/asm/bitops.h:16,
                 from include/linux/bitops.h:37,
                 from include/linux/kernel.h:10,
                 from include/linux/sched.h:15,
                 from include/linux/uaccess.h:5,
                 from /root/devmmap_paging/kernel/mykmod_main.c:4:
./arch/x86/include/asm/page_types.h:10:0: note: this is the location of the previous definition
 #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
 ^
/root/devmmap_paging/kernel/mykmod_main.c: In function ‘mykmod_cleanup_module’:
/root/devmmap_paging/kernel/mykmod_main.c:91:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  int i = 0;
  ^
/root/devmmap_paging/kernel/mykmod_main.c: In function ‘mykmod_open’:
/root/devmmap_paging/kernel/mykmod_main.c:106:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  struct mykmod_dev_info *info; // Creating a struct of type mykmod_dev_info to be able to store the info of the devices
  ^
/root/devmmap_paging/kernel/mykmod_main.c:115:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
   int i = 0;
   ^
/root/devmmap_paging/kernel/mykmod_main.c: In function ‘mykmod_mmap’:
/root/devmmap_paging/kernel/mykmod_main.c:151:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  struct mykmod_vma_info *info; // Creating an struct of mykmod_vma_info type to allow for the mapping of data
  ^
/root/devmmap_paging/kernel/mykmod_main.c: In function ‘mykmod_vm_fault’:
/root/devmmap_paging/kernel/mykmod_main.c:188:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
   struct page *page; // Creating a struct of type page
   ^
  LD [M]  /root/devmmap_paging/kernel/mykmod.o
  Building modules, stage 2.
  MODPOST 1 modules
  CC      /root/devmmap_paging/kernel/mykmod.mod.o
  LD [M]  /root/devmmap_paging/kernel/mykmod.ko
make[2]: Leaving directory `/usr/src/kernels/3.10.0-1062.9.1.el7.x86_64'
make[1]: Leaving directory `/root/devmmap_paging/kernel'
make[1]: Entering directory `/root/devmmap_paging/util'
g++ -std=c++11 -I ../include -I ../lib -L ../lib -lrt -o memutil  memutil.cpp -g -lpthread
make[1]: Leaving directory `/root/devmmap_paging/util'

[root@cs3523 devmmap_paging]# insmod kernel/mykmod.ko
[root@cs3523 devmmap_paging]# grep mykmod /proc/devices
243 mykmod

INSTRUCTIONS TO RUN (NOT USING THE TEST SCRIPT)

SYNTAX

Usage: ./util/memutil [options] <devname>
Options:
--operation <optype>  : Where optype can be mapread, mapwrite
--message <message>   : Message to be written/read-compare to/from the device memory
--paging <ptype>      : Where ptype can be prefetch or demand
--help                : Show this help

SAMPLE OUTPUTS WITHOUT USING TEST SCRIPT

CASE 1: PREFETCH (READ ONLY)

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_pR6 c 243 10
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_pR6 --pt prefetch --op mapread
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  151.570537] mykmod_vm_open: vma=ffff9a0f787961b0 npagefaults:0
[  151.572697] mykmod_vm_close: vma=ffff9a0f787961b0 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_pR6

CASE 2: DEMAND (READ ONLY)

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_JZ1 c 243 11
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_JZ1 --pt demand --op mapread
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  248.623157] mykmod_vm_open: vma=ffff9a0f78796288 npagefaults:0
[  248.623164] mykmod_vm_close: vma=ffff9a0f78796288 npagefaults:0

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_JZ1

CASE 3a: PREFETCH (READ AND WRITE): MESSAGE LENGTH <= PAGESIZE

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_fBc c 243 20
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_fBc --pt prefetch --op mapwrite --op mapread --mes test2
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  368.153225] mykmod_vm_open: vma=ffff9a0f78796360 npagefaults:0
[  368.153907] mykmod_vm_close: vma=ffff9a0f78796360 npagefaults:256
[  368.153915] mykmod_vm_open: vma=ffff9a0f78796360 npagefaults:0
[  368.165094] mykmod_vm_close: vma=ffff9a0f78796360 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_fBc

CASE 3b: PREFETCH (READ AND WRITE): MESSAGE LENGTH > PAGESIZE

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_fAc c 243 21
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_fAc --pt prefetch --op mapwrite --op mapread --mes ThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisenthereforealwaysholdsiinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewistothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprinciofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleoThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleoThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleoThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleshello
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  472.266659] mykmod_vm_open: vma=ffff9a0f73fed5e8 npagefaults:0
[  472.275885] mykmod_vm_close: vma=ffff9a0f73fed5e8 npagefaults:256
[  472.275910] mykmod_vm_open: vma=ffff9a0f73fed5e8 npagefaults:0
[  472.278093] mykmod_vm_close: vma=ffff9a0f73fed5e8 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_fAc

CASE 4a: DEMAND (READ AND WRITE): MESSAGE LENGTH <= PAGESIZE

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_Ln5 c 243 22
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_Ln5 --pt demand --op mapwrite --op mapread --mes test2
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  740.551923] mykmod_vm_open: vma=ffff9a0ff8d9b1b0 npagefaults:0
[  740.551950] mykmod_vm_close: vma=ffff9a0ff8d9b1b0 npagefaults:256
[  740.551956] mykmod_vm_open: vma=ffff9a0ff8d9b1b0 npagefaults:0
[  740.551965] mykmod_vm_close: vma=ffff9a0ff8d9b1b0 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_Ln5

CASE 4b: DEMAND (READ AND WRITE): MESSAGE LENGTH > PAGESIZE

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_Ln6 c 243 23
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_Ln6 --pt demand --op mapwrite --op mapread --mes ThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisenthereforealwaysholdsiinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewistothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprinciofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleoThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleoThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleoThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleofselectionThewisemanthereforealwaysholdsinthesematterstothisprincipleshello
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  861.559056] mykmod_vm_open: vma=ffff9a0f787ed870 npagefaults:0
[  861.559109] mykmod_vm_close: vma=ffff9a0f787ed870 npagefaults:256
[  861.559115] mykmod_vm_open: vma=ffff9a0f787ed870 npagefaults:0
[  861.559145] mykmod_vm_close: vma=ffff9a0f787ed870 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_Ln6

CASE 5: MULTIPLE PROCESS READING USING MAPPING

CASE 5a: PREFETCH

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_krt c 243 30
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_krt --pt prefetch --op mapread
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_krt --pt prefetch --op mapread
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  270.523497] mykmod_vm_open: vma=ffff89d937ecae58 npagefaults:0
[  270.524166] mykmod_vm_close: vma=ffff89d937ecae58 npagefaults:256
[  274.155160] mykmod_vm_open: vma=ffff89d8b66e4948 npagefaults:0
[  274.155770] mykmod_vm_close: vma=ffff89d8b66e4948 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_krt

CASE 5b: DEMAND PAGING

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_grt c 243 31
[root@cs3523 devmmap_paging]# ./util/memutil mydev_grt --pt demand --op mapread
[root@cs3523 devmmap_paging]# ./util/memutil mydev_grt --pt demand --op mapread
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  625.281761] mykmod_vm_open: vma=ffff9cfcf5556e58 npagefaults:0
[  625.281770] mykmod_vm_close: vma=ffff9cfcf5556e58 npagefaults:0
[  628.452384] mykmod_vm_open: vma=ffff9cfcf5556af8 npagefaults:0
[  628.452465] mykmod_vm_close: vma=ffff9cfcf5556af8 npagefaults:0

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_grt

CASE 6: MULTIPLE PROCESS WRITING USING MAPPING

CASE 6a: PREFETCH

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_asd c 243 40
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_asd --pt prefetch --op mapwrite --op mapread --mes test2a
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_asd --pt prefetch --op mapwrite --op mapread --mes test2b
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  127.262445] mykmod_vm_open: vma=ffff9c2435ef2438 npagefaults:0
[  127.267992] mykmod_vm_close: vma=ffff9c2435ef2438 npagefaults:256
[  127.268002] mykmod_vm_open: vma=ffff9c2435ef2438 npagefaults:0
[  127.284860] mykmod_vm_close: vma=ffff9c2435ef2438 npagefaults:256
[  130.923799] mykmod_vm_open: vma=ffff9c23b5836798 npagefaults:0
[  130.928635] mykmod_vm_close: vma=ffff9c23b5836798 npagefaults:256
[  130.928642] mykmod_vm_open: vma=ffff9c23b5836798 npagefaults:0
[  130.932848] mykmod_vm_close: vma=ffff9c23b5836798 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_asd

CASE 6b: DEMAND PAGING

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_qwe c 243 41
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_qwe --pt demand --op mapwrite --op mapread --mes test2c
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_qwe --pt demand --op mapwrite --op mapread --mes test2d
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[  380.011792] mykmod_vm_open: vma=ffff9c23b5a9cd80 npagefaults:0
[  380.027935] mykmod_vm_close: vma=ffff9c23b5a9cd80 npagefaults:256
[  380.027964] mykmod_vm_open: vma=ffff9c23b5a9cd80 npagefaults:0
[  380.044239] mykmod_vm_close: vma=ffff9c23b5a9cd80 npagefaults:256
[  383.357414] mykmod_vm_open: vma=ffff9c23b5a9cbd0 npagefaults:0
[  383.366874] mykmod_vm_close: vma=ffff9c23b5a9cbd0 npagefaults:256
[  383.366896] mykmod_vm_open: vma=ffff9c23b5a9cbd0 npagefaults:0
[  383.380902] mykmod_vm_close: vma=ffff9c23b5a9cbd0 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_qwe

CASE 7: ONE PROCESS WRITING USING MAPPING AND OTHER PROCESS READING USING MAPPING

CASE 7a: PREFETCH

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_zxc c 243 50
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_zxc --pt prefetch --op mapwrite --mes test7a
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_zxc --pt prefetch --op mapread --mes test7a
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[ 1002.808937] mykmod_vm_open: vma=ffff9c23b8fcfa20 npagefaults:0
[ 1002.813644] mykmod_vm_close: vma=ffff9c23b8fcfa20 npagefaults:256
[ 1025.277486] mykmod_vm_open: vma=ffff9c24379a2e58 npagefaults:0
[ 1025.285407] mykmod_vm_close: vma=ffff9c24379a2e58 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_zxc

CASE 7b: DEMAND PAGING

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_rty c 243 51
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_rty --pt demand --op mapwrite --mes test7b
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_rty --pt demand --op mapread --mes test7b
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[ 1155.964341] mykmod_vm_open: vma=ffff9c23b8617e58 npagefaults:0
[ 1155.972578] mykmod_vm_close: vma=ffff9c23b8617e58 npagefaults:256
[ 1168.019982] mykmod_vm_open: vma=ffff9c23b8617438 npagefaults:0
[ 1168.028819] mykmod_vm_close: vma=ffff9c23b8617438 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev_rty

CASE 8: ONE PROCESS WRITING TO ONE DEV AND OTHER PROCESS READING FROM ANOTHER DEV

CASE 8a: PREFETCH

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_qw1 c 243 60
[root@cs3523 devmmap_paging]# mknod /tmp/mydev_qw2 c 243 70
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_qw1 --pt prefetch --op mapwrite --mes test8a
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_qw2 --pt prefetch --op mapread 2> /dev/null
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[ 1312.644292] mykmod_vm_open: vma=ffff9c23b8617bd0 npagefaults:0
[ 1312.671105] mykmod_vm_close: vma=ffff9c23b8617bd0 npagefaults:256
[ 1355.097147] mykmod_vm_open: vma=ffff9c23b8617798 npagefaults:0
[ 1355.098022] mykmod_vm_close: vma=ffff9c23b8617798 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev*

CASE 8b: DEMAND PAGING

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_aw1 c 243 61
[root@cs3523 devmmap_paging]# mknod /tmp/mydev_aw2 c 243 71
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_aw1 --pt demand --op mapwrite --mes test8b
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_aw2 --pt demand --op mapread 2> /dev/null
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close

[ 1564.113160] mykmod_vm_open: vma=ffff9c24379a2ca8 npagefaults:0
[ 1564.121769] mykmod_vm_close: vma=ffff9c24379a2ca8 npagefaults:256
[ 1583.809507] mykmod_vm_open: vma=ffff9c24379a2e58 npagefaults:0
[ 1583.809533] mykmod_vm_close: vma=ffff9c24379a2e58 npagefaults:0

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev*

CASE 9: MEMORY MAPPING WITH A NON ZERO OFFSET (Setting offset_t off = 4096 in memutil.cpp)

CASE 9a: PREFETCH

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_pR6 c 243 10
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_pR6 --pt prefetch --op mapread
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close
[   97.523685] mykmod_vm_open: vma=ffff8aa575d531b0 npagefaults:0
[   97.524498] mykmod_vm_close: vma=ffff8aa575d531b0 npagefaults:256
[root@cs3523 devmmap_paging]# mknod /tmp/mydev_fBc c 243 20
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_fBc --pt prefetch --op mapwrite --op mapread --mes test2
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close
[   97.523685] mykmod_vm_open: vma=ffff8aa575d531b0 npagefaults:0
[   97.524498] mykmod_vm_close: vma=ffff8aa575d531b0 npagefaults:256
[  118.309585] mykmod_vm_open: vma=ffff8aa5f8dff6c0 npagefaults:0
[  118.339803] mykmod_vm_close: vma=ffff8aa5f8dff6c0 npagefaults:256
[  118.339904] mykmod_vm_open: vma=ffff8aa677388a20 npagefaults:0
[  118.346404] mykmod_vm_close: vma=ffff8aa677388a20 npagefaults:256

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev*

CASE 9b: DEMAND PAGING:

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_JZl c 243 11
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_JZl --pt demand --op mapread
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close
[  124.246823] mykmod_vm_open: vma=ffff9517fab545e8 npagefaults:0
[  124.246849] mykmod_vm_close: vma=ffff9517fab545e8 npagefaults:0
[root@cs3523 devmmap_paging]# mknod /tmp/mydev_Ln5 c 243 21
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_Ln5 --pt demand --op mapwrite --op mapread --mes test2
[root@cs3523 devmmap_paging]# dmesg | grep -e mykmod_vm_open -e mykmod_vm_close
[  124.246823] mykmod_vm_open: vma=ffff9517fab545e8 npagefaults:0
[  124.246849] mykmod_vm_close: vma=ffff9517fab545e8 npagefaults:0
[  151.983395] mykmod_vm_open: vma=ffff9517fa8b0af8 npagefaults:0
[  151.991419] mykmod_vm_close: vma=ffff9517fa8b0af8 npagefaults:255
[  151.991431] mykmod_vm_open: vma=ffff9517fa8b0af8 npagefaults:0
[  151.996843] mykmod_vm_close: vma=ffff9517fa8b0af8 npagefaults:255

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev*

CASE 10: MEMORY MAPPING SUCH THAT IT EXCEEDS THE DEVICE FILE BOUNDS

[root@cs3523 devmmap_paging]# mknod /tmp/mydev_JZl c 243 11
[root@cs3523 devmmap_paging]# ./util/memutil /tmp/mydev_JZl --pt demand --op mapread
mmap read failed: Invalid argument

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev*

UNLOADING THE DRIVER

INSTRUCTIONS:

[root@cs3523 devmmap_paging]# rm -f /tmp/mydev*
[root@cs3523 devmmap_paging]# rmmod mykmod

SAMPLE OUTPUT USING THE TEST SCRIPT PROVIDED

BUILDING AND LOAD THE DRIVER AS PER INSTRUCTIONS ABOVE THEN EXECUTING THE TEST SCRIPT

[root@cs3523 ~]# cd devmmap_paging/
[root@cs3523 devmmap_paging]# make
make[1]: Entering directory `/root/devmmap_paging/kernel'
make -C /lib/modules/3.10.0-1062.9.1.el7.x86_64/build M=/root/devmmap_paging/kernel modules
make[2]: Entering directory `/usr/src/kernels/3.10.0-1062.9.1.el7.x86_64'
  CC [M]  /root/devmmap_paging/kernel/mykmod_main.o
/root/devmmap_paging/kernel/mykmod_main.c:19:0: warning: "PAGE_SIZE" redefined [enabled by default]
 #define PAGE_SIZE 4096
 ^
In file included from ./arch/x86/include/asm/ptrace.h:5:0,
                 from ./arch/x86/include/asm/alternative.h:10,
                 from ./arch/x86/include/asm/bitops.h:16,
                 from include/linux/bitops.h:37,
                 from include/linux/kernel.h:10,
                 from include/linux/sched.h:15,
                 from include/linux/uaccess.h:5,
                 from /root/devmmap_paging/kernel/mykmod_main.c:4:
./arch/x86/include/asm/page_types.h:10:0: note: this is the location of the previous definition
 #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
 ^
/root/devmmap_paging/kernel/mykmod_main.c: In function ‘mykmod_cleanup_module’:
/root/devmmap_paging/kernel/mykmod_main.c:91:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  int i = 0;
  ^
/root/devmmap_paging/kernel/mykmod_main.c: In function ‘mykmod_open’:
/root/devmmap_paging/kernel/mykmod_main.c:106:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  struct mykmod_dev_info *info; // Creating a struct of type mykmod_dev_info to be able to store the info of the devices
  ^
/root/devmmap_paging/kernel/mykmod_main.c:115:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
   int i = 0;
   ^
/root/devmmap_paging/kernel/mykmod_main.c: In function ‘mykmod_mmap’:
/root/devmmap_paging/kernel/mykmod_main.c:151:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  struct mykmod_vma_info *info; // Creating an struct of mykmod_vma_info type to allow for the mapping of data
  ^
/root/devmmap_paging/kernel/mykmod_main.c: In function ‘mykmod_vm_fault’:
/root/devmmap_paging/kernel/mykmod_main.c:188:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
   struct page *page; // Creating a struct of type page
   ^
  LD [M]  /root/devmmap_paging/kernel/mykmod.o
  Building modules, stage 2.
  MODPOST 1 modules
  CC      /root/devmmap_paging/kernel/mykmod.mod.o
  LD [M]  /root/devmmap_paging/kernel/mykmod.ko
make[2]: Leaving directory `/usr/src/kernels/3.10.0-1062.9.1.el7.x86_64'
make[1]: Leaving directory `/root/devmmap_paging/kernel'
make[1]: Entering directory `/root/devmmap_paging/util'
g++ -std=c++11 -I ../include -I ../lib -L ../lib -lrt -o memutil  memutil.cpp -g -lpthread
make[1]: Leaving directory `/root/devmmap_paging/util'
[root@cs3523 devmmap_paging]# chmod +x runtest.sh 
[root@cs3523 devmmap_paging]# ./runtest.sh 
PASS - Test 0 : Module loaded with majorno: 243
PASS - Test 1 : Single process reading using mapping
PASS - Test 2 : Single process writing using mapping
PASS - Test 3 : Multiple process reading using mapping
PASS - Test 4 : Multiple process writing using mapping
PASS - Test 5 : One process writing using mapping and other process reading using mapping
PASS - Test 6 : One process writing to one dev and other process reading from another dev

Name		Name	Last commit message	Last commit date
Latest commit History 42 Commits
include		include
kernel		kernel
util		util
CS18BTECH11042_CS18BTECH11050.zip		CS18BTECH11042_CS18BTECH11050.zip
Makefile		Makefile
Problem_Statement_Paging_on_Device_Memory.pdf		Problem_Statement_Paging_on_Device_Memory.pdf
README.md		README.md
Report.pdf		Report.pdf
memutil.cpp		memutil.cpp
mykmod_main.c		mykmod_main.c
runtest.sh		runtest.sh

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devmmap_paging

OS-II Kernel Programming Assignment

LIST OF FILES SUBMITTED

COMPILATION INSTRUCTIONS

BUILDING AND LOADING THE DRIVER

INSTRUCTIONS TO RUN (NOT USING THE TEST SCRIPT)

SYNTAX

SAMPLE OUTPUTS WITHOUT USING TEST SCRIPT

CASE 1: PREFETCH (READ ONLY)

CASE 2: DEMAND (READ ONLY)

CASE 3a: PREFETCH (READ AND WRITE): MESSAGE LENGTH <= PAGESIZE

CASE 3b: PREFETCH (READ AND WRITE): MESSAGE LENGTH > PAGESIZE

CASE 4a: DEMAND (READ AND WRITE): MESSAGE LENGTH <= PAGESIZE

CASE 4b: DEMAND (READ AND WRITE): MESSAGE LENGTH > PAGESIZE

CASE 5: MULTIPLE PROCESS READING USING MAPPING

CASE 5a: PREFETCH

CASE 5b: DEMAND PAGING

CASE 6: MULTIPLE PROCESS WRITING USING MAPPING

CASE 6a: PREFETCH

CASE 6b: DEMAND PAGING

CASE 7: ONE PROCESS WRITING USING MAPPING AND OTHER PROCESS READING USING MAPPING

CASE 7a: PREFETCH

CASE 7b: DEMAND PAGING

CASE 8: ONE PROCESS WRITING TO ONE DEV AND OTHER PROCESS READING FROM ANOTHER DEV

CASE 8a: PREFETCH

CASE 8b: DEMAND PAGING

CASE 9: MEMORY MAPPING WITH A NON ZERO OFFSET (Setting offset_t off = 4096 in memutil.cpp)

CASE 9a: PREFETCH

CASE 9b: DEMAND PAGING:

CASE 10: MEMORY MAPPING SUCH THAT IT EXCEEDS THE DEVICE FILE BOUNDS

UNLOADING THE DRIVER

INSTRUCTIONS:

SAMPLE OUTPUT USING THE TEST SCRIPT PROVIDED

BUILDING AND LOAD THE DRIVER AS PER INSTRUCTIONS ABOVE THEN EXECUTING THE TEST SCRIPT

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