linux-systems.md

Memory

• What is basic memory layout of a process

Processes

• Describe how processes are created
• What's the difference between fork/ clone?

Resource Control

• What are the basic techniques for resource control?

Linux history

• What is POSIX
• What is the GNU Project
• What is the standard C library

Syscalls

• accept (2) - accept a connection on a socket
• accept4 (2) - accept a connection on a socket
• access (2) - check real user's permissions for a file
• acct (2) - switch process accounting on or off
• add_key (2) - add a key to the kernel's key management facility
• adjtimex (2) - tune kernel clock
• alarm (2) - set an alarm clock for delivery of a signal
• alloc_hugepages (2) - allocate or free huge pages
• arch_prctl (2) - set architecture-specific thread state
• arm_fadvise (2) - predeclare an access pattern for file data
• arm_fadvise64_64 (2) - predeclare an access pattern for file data
• arm_sync_file_range (2) - sync a file segment with disk
• bdflush (2) - start, flush, or tune buffer-dirty-flush daemon
• bind (2) - bind a name to a socket
• brk (2) - change data segment size
• cacheflush (2) - flush contents of instruction and/or data cache
• capget (2) - set/get capabilities of thread(s)
• capset (2) - set/get capabilities of thread(s)
• chdir (2) - change working directory
• chmod (2) - change permissions of a file
• chown (2) - change ownership of a file
• chown32 (2) - change ownership of a file
• chroot (2) - change root directory
• clock_getres (2) - clock and time functions
• clock_gettime (2) - clock and time functions
• clock_nanosleep (2) - high-resolution sleep with specifiable clock
• clock_settime (2) - clock and time functions
• clone2 (2) - create a child process
• clone2 (2) - create a child process
• clone (2) - create a child process
• close (2) - close a file descriptor
• connect (2) - initiate a connection on a socket
• creat (2) - open and possibly create a file or device
• create_module (2) - create a loadable module entry
• delete_module (2) - unload a kernel module
• dup2 (2) - duplicate a file descriptor
• dup (2) - duplicate a file descriptor
• dup3 (2) - duplicate a file descriptor
• epoll_create1 (2) - open an epoll file descriptor
• epoll_create (2) - open an epoll file descriptor
• epoll_ctl (2) - control interface for an epoll descriptor
• epoll_pwait (2) - wait for an I/O event on an epoll file descriptor
• epoll_wait (2) - wait for an I/O event on an epoll file descriptor
• eventfd2 (2) - create a file descriptor for event notification
• eventfd (2) - create a file descriptor for event notification
• execve (2) - execute program
• _exit (2) - terminate the calling process
• exit (2) - terminate the calling process
• _Exit (2) - terminate the calling process
• exit_group (2) - exit all threads in a process
• faccessat (2) - check user's permissions of a file relative to a direc...
• fadvise64 (2) - predeclare an access pattern for file data
• fadvise64_64 (2) - predeclare an access pattern for file data
• fallocate (2) - manipulate file space
• fanotify_init (2) - create and initialize fanotify group
• fchdir (2) - change working directory
• fchmod (2) - change permissions of a file
• fchmodat (2) - change permissions of a file relative to a directory f...
• fchown (2) - change ownership of a file
• fchown32 (2) - change ownership of a file
• fchownat (2) - change ownership of a file relative to a directory fil...
• fcntl (2) - manipulate file descriptor
• fcntl64 (2) - manipulate file descriptor
• fdatasync (2) - synchronize a file's in-core state with storage device
• finit_module (2) - load a kernel module
• flock (2) - apply or remove an advisory lock on an open file
• fork (2) - create a child process
• free_hugepages (2) - allocate or free huge pages
• fstat (2) - get file status
• fstat64 (2) - get file status
• fstatat (2) - get file status relative to a directory file descriptor
• fstatat64 (2) - get file status relative to a directory file descriptor
• fstatfs (2) - get file system statistics
• fstatfs64 (2) - get file system statistics
• fstatvfs (2) - get file system statistics
• fsync (2) - synchronize a file's in-core state with storage device
• ftruncate (2) - truncate a file to a specified length
• ftruncate64 (2) - truncate a file to a specified length
• futex (2) - fast user-space locking
• futimesat (2) - change timestamps of a file relative to a directory fi...
• getcontext (2) - get or set the user context
• getcpu (2) - determine CPU and NUMA node on which the calling threa...
• getcwd (2) - get current working directory
• getdents (2) - get directory entries
• getdents64 (2) - get directory entries
• getdomainname (2) - get/set NIS domain name
• getdtablesize (2) - get descriptor table size
• getegid (2) - get group identity
• getegid32 (2) - get group identity
• geteuid (2) - get user identity
• geteuid32 (2) - get user identity
• getgid (2) - get group identity
• getgid32 (2) - get group identity
• getgroups (2) - get/set list of supplementary group IDs
• getgroups32 (2) - get/set list of supplementary group IDs
• gethostid (2) - get or set the unique identifier of the current host
• gethostname (2) - get/set hostname
• getitimer (2) - get or set value of an interval timer
• get_kernel_syms (2) - retrieve exported kernel and module symbols
• get_mempolicy (2) - retrieve NUMA memory policy for a process
• getpagesize (2) - get memory page size
• getpeername (2) - get name of connected peer socket
• getpgid (2) - set/get process group
• getpgrp (2) - set/get process group
• getpid (2) - get process identification
• getppid (2) - get process identification
• getpriority (2) - get/set program scheduling priority
• getresgid (2) - get real, effective and saved user/group IDs
• getresgid32 (2) - get real, effective and saved user/group IDs
• getresuid (2) - get real, effective and saved user/group IDs
• getresuid32 (2) - get real, effective and saved user/group IDs
• getrlimit (2) - get/set resource limits
• get_robust_list (2) - get/set list of robust futexes
• getrusage (2) - get resource usage
• getsid (2) - get session ID
• getsockname (2) - get socket name
• getsockopt (2) - get and set options on sockets
• get_thread_area (2) - get a thread-local storage (TLS) area
• gettid (2) - get thread identification
• gettimeofday (2) - get / set time
• getuid (2) - get user identity
• getuid32 (2) - get user identity
• getunwind (2) - copy the unwind data to caller's buffer
• idle (2) - make process 0 idle
• inb (2) - port I/O
• inb_p (2) - port I/O
• init_module (2) - load a kernel module
• inl (2) - port I/O
• inl_p (2) - port I/O
• inotify_add_watch (2) - add a watch to an initialized inotify instance
• inotify_init1 (2) - initialize an inotify instance
• inotify_init (2) - initialize an inotify instance
• inotify_rm_watch (2) - remove an existing watch from an inotify instance
• insb (2) - port I/O
• insl (2) - port I/O
• insw (2) - port I/O
• intro (2) - introduction to system calls
• inw (2) - port I/O
• inw_p (2) - port I/O
• io_cancel (2) - cancel an outstanding asynchronous I/O operation
• ioctl (2) - control device
• ioctl_list (2) - list of ioctl calls in Linux/i386 kernel
• io_destroy (2) - destroy an asynchronous I/O context
• io_getevents (2) - read asynchronous I/O events from the completion queue
• ioperm (2) - set port input/output permissions
• iopl (2) - change I/O privilege level
• ioprio_get (2) - get/set I/O scheduling class and priority
• ioprio_set (2) - get/set I/O scheduling class and priority
• io_setup (2) - create an asynchronous I/O context
• io_submit (2) - submit asynchronous I/O blocks for processing
• ipc (2) - System V IPC system calls
• kcmp (2) - compare two processes to determine if they share a ker...
• kexec_load (2) - load a new kernel for later execution
• keyctl (2) - manipulate the kernel's key management facility
• kill (2) - send signal to a process
• killpg (2) - send signal to a process group
• lchown (2) - change ownership of a file
• lchown32 (2) - change ownership of a file
• link (2) - make a new name for a file
• linkat (2) - create a file link relative to directory file descriptors
• listen (2) - listen for connections on a socket
• _llseek (2) - reposition read/write file offset
• llseek (2) - reposition read/write file offset
• lookup_dcookie (2) - return a directory entry's path
• lseek (2) - reposition read/write file offset
• lstat (2) - get file status
• lstat64 (2) - get file status
• madvise (2) - give advice about use of memory
• mbind (2) - set memory policy for a memory range
• migrate_pages (2) - move all pages in a process to another set of nodes
• mincore (2) - determine whether pages are resident in memory
• mkdir (2) - create a directory
• mkdirat (2) - create a directory relative to a directory file descri...
• mknod (2) - create a special or ordinary file
• mknodat (2) - create a special or ordinary file relative to a direct...
• mlock (2) - lock and unlock memory
• mlockall (2) - lock and unlock memory
• mmap2 (2) - map files or devices into memory
• mmap (2) - map or unmap files or devices into memory
• modify_ldt (2) - get or set ldt
• mount (2) - mount file system
• move_pages (2) - move individual pages of a process to another node
• mprotect (2) - set protection on a region of memory
• mq_getsetattr (2) - get/set message queue attributes
• mq_notify (2) - register for notification when a message is available
• mq_open (2) - open a message queue
• mq_timedreceive (2) - receive a message from a message queue
• mq_timedsend (2) - send a message to a message queue
• mq_unlink (2) - remove a message queue
• mremap (2) - remap a virtual memory address
• msgctl (2) - System V message control operations
• msgget (2) - get a System V message queue identifier
• msgop (2) - System V message queue operations
• msgrcv (2) - System V message queue operations
• msgsnd (2) - System V message queue operations
• msync (2) - synchronize a file with a memory map
• munlock (2) - lock and unlock memory
• munlockall (2) - lock and unlock memory
• munmap (2) - map or unmap files or devices into memory
• nanosleep (2) - high-resolution sleep
• _newselect (2) - synchronous I/O multiplexing
• nfsservctl (2) - syscall interface to kernel nfs daemon
• nice (2) - change process priority
• oldfstat (2) - get file status
• oldlstat (2) - get file status
• oldolduname (2) - get name and information about current kernel
• oldstat (2) - get file status
• olduname (2) - get name and information about current kernel
• open (2) - open and possibly create a file or device
• openat (2) - open a file relative to a directory file descriptor
• outb (2) - port I/O
• outb_p (2) - port I/O
• outl (2) - port I/O
• outl_p (2) - port I/O
• outsb (2) - port I/O
• outsl (2) - port I/O
• outsw (2) - port I/O
• outw (2) - port I/O
• outw_p (2) - port I/O
• pause (2) - wait for signal
• perf_event_open (2) - set up performance monitoring
• perfmonctl (2) - interface to IA-64 performance monitoring unit
• personality (2) - set the process execution domain
• pipe2 (2) - create pipe
• pipe (2) - create pipe
• pivot_root (2) - change the root file system
• poll (2) - wait for some event on a file descriptor
• posix_fadvise (2) - predeclare an access pattern for file data
• ppoll (2) - wait for some event on a file descriptor
• prctl (2) - operations on a process
• pread (2) - read from or write to a file descriptor at a given offset
• pread64 (2) - read from or write to a file descriptor at a given offset
• preadv (2) - read or write data into multiple buffers
• process_vm_readv (2) - transfer data between process address spaces
• process_vm_writev (2) - transfer data between process address spaces
• pselect (2) - synchronous I/O multiplexing
• pselect6 (2) - synchronous I/O multiplexing
• ptrace (2) - process trace
• pwrite (2) - read from or write to a file descriptor at a given offset
• pwrite64 (2) - read from or write to a file descriptor at a given offset
• pwritev (2) - read or write data into multiple buffers
• query_module (2) - query the kernel for various bits pertaining to modules
• quotactl (2) - manipulate disk quotas
• read (2) - read from a file descriptor
• readahead (2) - perform file readahead into page cache
• readdir (2) - read directory entry
• readlink (2) - read value of a symbolic link
• readlinkat (2) - read value of a symbolic link relative to a directory ...
• readv (2) - read or write data into multiple buffers
• reboot (2) - reboot or enable/disable Ctrl-Alt-Del
• recv (2) - receive a message from a socket
• recvfrom (2) - receive a message from a socket
• recvmmsg (2) - receive multiple messages on a socket
• recvmsg (2) - receive a message from a socket
• remap_file_pages (2) - create a nonlinear file mapping
• rename (2) - change the name or location of a file
• renameat (2) - rename a file relative to directory file descriptors
• request_key (2) - request a key from the kernel's key management facility
• restart_syscall (2) - restart a system call after interruption by a stop signal
• rmdir (2) - delete a directory
• rtas (2) - Allows userspace to call RTAS (Run Time Abstraction Se...
• rt_sigaction (2) - examine and change a signal action
• rt_sigpending (2) - examine pending signals
• rt_sigprocmask (2) - examine and change blocked signals
• rt_sigqueueinfo (2) - queue a signal and data
• rt_sigreturn (2) - return from signal handler and cleanup stack frame
• rt_sigsuspend (2) - wait for a signal
• rt_sigtimedwait (2) - synchronously wait for queued signals
• rt_tgsigqueueinfo (2) - queue a signal and data
• s390_runtime_instr (2) - enable/disable s390 CPU run-time instrumentation
• sbrk (2) - change data segment size
• sched_getaffinity (2) - set and get a process's CPU affinity mask
• sched_getparam (2) - set and get scheduling parameters
• sched_get_priority_max (2) - get static priority range
• sched_get_priority_min (2) - get static priority range
• sched_getscheduler (2) - set and get scheduling policy/parameters
• sched_rr_get_interval (2) - get the SCHED_RR interval for the named process
• sched_setaffinity (2) - set and get a process's CPU affinity mask
• sched_setparam (2) - set and get scheduling parameters
• sched_setscheduler (2) - set and get scheduling policy/parameters
• sched_yield (2) - yield the processor
• select (2) - synchronous I/O multiplexing
• select_tut (2) - synchronous I/O multiplexing
• semctl (2) - System V semaphore control operations
• semget (2) - get a System V semaphore set identifier
• semop (2) - System V semaphore operations
• semtimedop (2) - System V semaphore operations
• send (2) - send a message on a socket
• sendfile (2) - transfer data between file descriptors
• sendfile64 (2) - transfer data between file descriptors
• sendmmsg (2) - send multiple messages on a socket
• sendmsg (2) - send a message on a socket
• sendto (2) - send a message on a socket
• setcontext (2) - get or set the user context
• setegid (2) - set effective user or group ID
• seteuid (2) - set effective user or group ID
• setfsgid (2) - set group identity used for file system checks
• setfsgid32 (2) - set group identity used for file system checks
• setfsuid (2) - set user identity used for file system checks
• setfsuid32 (2) - set user identity used for file system checks
• setgid (2) - set group identity
• setgid32 (2) - set group identity
• setgroups (2) - get/set list of supplementary group IDs
• setgroups32 (2) - get/set list of supplementary group IDs
• sethostid (2) - get or set the unique identifier of the current host
• sethostname (2) - get/set hostname
• setitimer (2) - get or set value of an interval timer
• set_mempolicy (2) - set default NUMA memory policy for a process and its c...
• setns (2) - reassociate thread with a namespace
• setpgid (2) - set/get process group
• setpgrp (2) - set/get process group
• setpriority (2) - get/set program scheduling priority
• setregid (2) - set real and/or effective user or group ID
• setregid32 (2) - set real and/or effective user or group ID
• setresgid (2) - set real, effective and saved user or group ID
• setresgid32 (2) - set real, effective and saved user or group ID
• setresuid (2) - set real, effective and saved user or group ID
• setresuid32 (2) - set real, effective and saved user or group ID
• setreuid (2) - set real and/or effective user or group ID
• setreuid32 (2) - set real and/or effective user or group ID
• set_robust_list (2) - get/set list of robust futexes
• setsid (2) - creates a session and sets the process group ID
• setsockopt (2) - get and set options on sockets
• set_thread_area (2) - set a thread local storage (TLS) area
• set_tid_address (2) - set pointer to thread ID
• settimeofday (2) - get / set time
• setuid (2) - set user identity
• setuid32 (2) - set user identity
• setup (2) - setup devices and file systems, mount root file system
• sgetmask (2) - manipulation of signal mask (obsolete)
• shmat (2) - System V shared memory operations
• shmctl (2) - System V shared memory control
• shmdt (2) - System V shared memory operations
• shmget (2) - allocates a System V shared memory segment
• shmop (2) - System V shared memory operations
• shutdown (2) - shut down part of a full-duplex connection
• sigaction (2) - examine and change a signal action
• sigaltstack (2) - set and/or get signal stack context
• signal (2) - ANSI C signal handling
• signalfd (2) - create a file descriptor for accepting signals
• signalfd4 (2) - create a file descriptor for accepting signals
• sigpending (2) - examine pending signals
• sigprocmask (2) - examine and change blocked signals
• sigqueue (2) - queue a signal and data to a process
• sigreturn (2) - return from signal handler and cleanup stack frame
• sigsuspend (2) - wait for a signal
• sigtimedwait (2) - synchronously wait for queued signals
• sigwaitinfo (2) - synchronously wait for queued signals
• socket (2) - create an endpoint for communication
• socketcall (2) - socket system calls
• socketpair (2) - create a pair of connected sockets
• splice (2) - splice data to/from a pipe
• spu_create (2) - create a new spu context
• spu_run (2) - execute an SPU context
• ssetmask (2) - manipulation of signal mask (obsolete)
• stat (2) - get file status
• stat64 (2) - get file status
• statfs (2) - get file system statistics
• statfs64 (2) - get file system statistics
• statvfs (2) - get file system statistics
• stime (2) - set time
• subpage_prot (2) - define a subpage protection for an address range
• swapcontext (2) - Swap out old context with new context
• swapoff (2) - start/stop swapping to file/device
• swapon (2) - start/stop swapping to file/device
• symlink (2) - make a new name for a file
• symlinkat (2) - create a symbolic link relative to a directory file de...
• sync (2) - commit buffer cache to disk
• sync_file_range2 (2) - sync a file segment with disk
• sync_file_range (2) - sync a file segment with disk
• syncfs (2) - commit buffer cache to disk
• syscall (2) - indirect system call
• _syscall (2) - invoking a system call without library support (OBSOLETE)
• syscalls (2) - Linux system calls
• _sysctl (2) - read/write system parameters
• sysctl (2) - read/write system parameters
• sysfs (2) - get file system type information
• sysinfo (2) - returns information on overall system statistics
• syslog (2) - read and/or clear kernel message ring buffer; set cons...
• tee (2) - duplicating pipe content
• tgkill (2) - send a signal to a thread
• time (2) - get time in seconds
• timer_create (2) - create a POSIX per-process timer
• timer_delete (2) - delete a POSIX per-process timer
• timerfd_create (2) - timers that notify via file descriptors
• timerfd_gettime (2) - timers that notify via file descriptors
• timerfd_settime (2) - timers that notify via file descriptors
• timer_getoverrun (2) - get overrun count for a POSIX per-process timer
• timer_gettime (2) - arm/disarm and fetch state of POSIX per-process timer
• timer_settime (2) - arm/disarm and fetch state of POSIX per-process timer
• times (2) - get process times
• tkill (2) - send a signal to a thread
• truncate (2) - truncate a file to a specified length
• truncate64 (2) - truncate a file to a specified length
• ugetrlimit (2) - get/set resource limits
• umask (2) - set file mode creation mask
• umount2 (2) - unmount file system
• umount (2) - unmount file system
• uname (2) - get name and information about current kernel
• unlink (2) - delete a name and possibly the file it refers to
• unlinkat (2) - remove a directory entry relative to a directory file ...
• unshare (2) - disassociate parts of the process execution context
• uselib (2) - load shared library
• ustat (2) - get file system statistics
• utime (2) - change file last access and modification times
• utimensat (2) - change file timestamps with nanosecond precision
• utimes (2) - change file last access and modification times
• vfork (2) - create a child process and block parent
• vhangup (2) - virtually hangup the current terminal
• vm86 (2) - enter virtual 8086 mode
• vm86old (2) - enter virtual 8086 mode
• vmsplice (2) - splice user pages into a pipe
• wait (2) - wait for process to change state
• wait3 (2) - wait for process to change state, BSD style
• wait4 (2) - wait for process to change state, BSD style
• waitid (2) - wait for process to change state
• waitpid (2) - wait for process to change state
• write (2) - write to a file descriptor
• writev (2) - read or write data into multiple buffers