2016-11-07 14:44:24 +00:00
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.\" Copyright (c) 2016 by Michael Kerrisk <mtk.manpages@gmail.com>
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.\"
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.\" %%%LICENSE_START(VERBATIM)
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getent.1, ldd.1, locale.1, localedef.1, memusage.1, memusagestat.1, mtrace.1, _exit.2, _syscall.2, accept.2, access.2, acct.2, add_key.2, adjtimex.2, alloc_hugepages.2, arch_prctl.2, bdflush.2, bind.2, bpf.2, brk.2, cacheflush.2, capget.2, chdir.2, chmod.2, chown.2, chroot.2, clock_getres.2, clock_nanosleep.2, clone.2, close.2, close_range.2, connect.2, copy_file_range.2, create_module.2, delete_module.2, dup.2, epoll_create.2, epoll_ctl.2, epoll_wait.2, eventfd.2, execve.2, execveat.2, fanotify_init.2, fanotify_mark.2, fcntl.2, flock.2, fork.2, fsync.2, futex.2, get_kernel_syms.2, get_mempolicy.2, get_robust_list.2, getcpu.2, getdents.2, getdomainname.2, getgid.2, getgroups.2, gethostname.2, getitimer.2, getpagesize.2, getpeername.2, getpid.2, getpriority.2, getrandom.2, getresuid.2, getrlimit.2, getrusage.2, getsid.2, getsockname.2, getsockopt.2, gettid.2, gettimeofday.2, getuid.2, getunwind.2, getxattr.2, idle.2, init_module.2, inotify_add_watch.2, inotify_rm_watch.2, io_cancel.2, io_destroy.2, io_getevents.2, io_setup.2, io_submit.2, ioctl.2, ioctl_console.2, ioctl_fat.2, ioctl_ficlonerange.2, ioctl_fideduperange.2, ioctl_fslabel.2, ioctl_getfsmap.2, ioctl_ns.2, ioctl_tty.2, ioctl_userfaultfd.2, ioperm.2, iopl.2, ipc.2, kcmp.2, kexec_load.2, keyctl.2, kill.2, link.2, listen.2, listxattr.2, llseek.2, lookup_dcookie.2, lseek.2, madvise.2, mbind.2, membarrier.2, memfd_create.2, migrate_pages.2, mincore.2, mkdir.2, mknod.2, mlock.2, mmap.2, mmap2.2, modify_ldt.2, mount.2, move_pages.2, mprotect.2, mq_getsetattr.2, mremap.2, msgctl.2, msgget.2, msgop.2, msync.2, nanosleep.2, nfsservctl.2, nice.2, open.2, open_by_handle_at.2, openat2.2, pause.2, pciconfig_read.2, perf_event_open.2, perfmonctl.2, personality.2, pidfd_getfd.2, pidfd_open.2, pidfd_send_signal.2, pipe.2, pivot_root.2, pkey_alloc.2, poll.2, posix_fadvise.2, prctl.2, pread.2, process_vm_readv.2, ptrace.2, query_module.2, quotactl.2, read.2, readahead.2, readdir.2, readlink.2, readv.2, reboot.2, recv.2, remap_file_pages.2, removexattr.2, rename.2, request_key.2, restart_syscall.2, rmdir.2, rt_sigqueueinfo.2, s390_guarded_storage.2, s390_pci_mmio_write.2, s390_runtime_instr.2, s390_sthyi.2, sched_get_priority_max.2, sched_rr_get_interval.2, sched_setaffinity.2, sched_setattr.2, sched_setparam.2, sched_setscheduler.2, sched_yield.2, seccomp.2, select.2, select_tut.2, semctl.2, semget.2, semop.2, send.2, sendfile.2, set_thread_area.2, seteuid.2, setfsgid.2, setfsuid.2, setgid.2, setpgid.2, setresuid.2, setreuid.2, setsid.2, setuid.2, setup.2, setxattr.2, sgetmask.2, shmctl.2, shmget.2, shmop.2, shutdown.2, sigaction.2, sigaltstack.2, signal.2, signalfd.2, sigpending.2, sigprocmask.2, sigreturn.2, sigsuspend.2, sigwaitinfo.2, socket.2, socketcall.2, socketpair.2, splice.2, spu_create.2, spu_run.2, stat.2, statfs.2, statx.2, stime.2, subpage_prot.2, swapon.2, symlink.2, sync.2, sync_file_range.2, syscall.2, syscalls.2, sysctl.2, sysfs.2, sysinfo.2, syslog.2, time.2, timer_create.2, timer_delete.2, timer_getoverrun.2, timer_settime.2, timerfd_create.2, times.2, tkill.2, truncate.2, umask.2, umount.2, uname.2, unimplemented.2, unlink.2, unshare.2, uselib.2, userfaultfd.2, ustat.2, utime.2, utimensat.2, vfork.2, vhangup.2, vm86.2, vmsplice.2, wait.2, wait4.2, write.2, CPU_SET.3, __ppc_get_timebase.3, __ppc_set_ppr_med.3, __ppc_yield.3, __setfpucw.3, a64l.3, abort.3, abs.3, acos.3, acosh.3, addseverity.3, adjtime.3, aio_cancel.3, aio_error.3, aio_fsync.3, aio_read.3, aio_return.3, aio_suspend.3, aio_write.3, alloca.3, argz_add.3, asin.3, asinh.3, asprintf.3, assert.3, assert_perror.3, atan.3, atan2.3, atanh.3, atexit.3, atof.3, atoi.3, backtrace.3, basename.3, bcmp.3, bcopy.3, bindresvport.3, bsd_signal.3, bsearch.3, bstring.3, btowc.3, byteorder.3, bzero.3, cabs.3, cacos.3, cacosh.3, canonicalize_file_name.3, carg.3, casin.3, casinh.3, catan.3, catanh.3, catgets.3, catopen.3, cbrt.3, ccos.3, ccosh.3, ceil.3, cexp.3, cexp2.3, cfree.3, cimag.3, circleq.3, clearenv.3, clock.3, clock_getcpuclockid.3, clog.3, clog10.3, clog2.3, closedir.3, cmsg.3, confstr.3, conj.3, copysign.3, cos.3, cosh.3, cpow.3, cproj.3, creal.3, crypt.3, csin.3, csinh.3, csqrt.3, ctan.3, ctanh.3, ctermid.3, ctime.3, daemon.3, des_crypt.3, difftime.3, dirfd.3, div.3, dl_iterate_phdr.3, dladdr.3, dlerror.3, dlinfo.3, dlopen.3, dlsym.3, drand48.3, drand48_r.3, duplocale.3, dysize.3, ecvt.3, ecvt_r.3, encrypt.3, endian.3, envz_add.3, erf.3, erfc.3, err.3, errno.3, error.3, ether_aton.3, euidaccess.3, exec.3, exit.3, exp.3, exp10.3, exp2.3, expm1.3, fabs.3, fclose.3, fcloseall.3, fdim.3, fenv.3, ferror.3, fexecve.3, fflush.3, ffs.3, fgetc.3, fgetgrent.3, fgetpwent.3, fgetwc.3, fgetws.3, fileno.3, finite.3, flockfile.3, floor.3, fma.3, fmax.3, fmemopen.3, fmin.3, fmod.3, fmtmsg.3, fnmatch.3, fopen.3, fopencookie.3, fpathconf.3, fpclassify.3, fpurge.3, fputwc.3, fputws.3, fread.3, frexp.3, fseek.3, fseeko.3, ftime.3, ftok.3, fts.3, ftw.3, futimes.3, fwide.3, gamma.3, gcvt.3, get_nprocs_conf.3, get_phys_pages.3, getaddrinfo.3, getaddrinfo_a.3, getauxval.3, getcontext.3, getcwd.3, getdate.3, getdirentries.3, getdtablesize.3, getentropy.3, getenv.3, getfsent.3, getgrent.3, getgrent_r.3, getgrnam.3, getgrouplist.3, gethostbyname.3, gethostid.3, getifaddrs.3, getipnodebyname.3, getline.3, getloadavg.3, getlogin.3, getmntent.3, getnameinfo.3, getnetent.3, getnetent_r.3, getopt.3, getpass.3, getprotoent.3, getprotoent_r.3, getpt.3, getpw.3, getpwent.3, getpwent_r.3, getpwnam.3, getrpcent.3, getrpcent_r.3, getrpcport.3, gets.3, getservent.3, getservent_r.3, getspnam.3, getsubopt.3, getttyent.3, getumask.3, getusershell.3, getutent.3, getutmp.3, getw.3, getwchar.3, glob.3, gnu_get_libc_version.3, grantpt.3, group_member.3, gsignal.3, hsearch.3, hypot.3, iconv.3, iconv_close.3, iconv_open.3, if_nameindex.3, if_nametoindex.3, ilogb.3, index.3, inet.3, inet_net_pton.3, inet_ntop.3, inet_pton.3, initgroups.3, insque.3, isalpha.3, isatty.3, isfdtype.3, isgreater.3, iswalnum.3, iswalpha.3, iswblank.3, iswcntrl.3, iswctype.3, iswdigit.3, iswgraph.3, iswlower.3, iswprint.3, iswpunct.3, iswspace.3, iswupper.3, iswxdigit.3, j0.3, key_setsecret.3, killpg.3, ldexp.3, lgamma.3, lio_listio.3, list.3, localeconv.3, lockf.3, log.3, log10.3, log1p.3, log2.3, logb.3, login.3, lrint.3, lround.3, lsearch.3, lseek64.3, makecontext.3, makedev.3, mallinfo.3, malloc.3, malloc_get_state.3, malloc_hook.3, malloc_info.3, malloc_stats.3, malloc_trim.3, malloc_usable_size.3, mallopt.3, matherr.3, mblen.3, mbrlen.3, mbrtowc.3, mbsinit.3, mbsnrtowcs.3, mbsrtowcs.3, mbstowcs.3, mbtowc.3, mcheck.3, memccpy.3, memchr.3, memcmp.3, memcpy.3, memfrob.3, memmem.3, memmove.3, mempcpy.3, memset.3, mkdtemp.3, mkfifo.3, mkstemp.3, mktemp.3, modf.3, mpool.3, mq_close.3, mq_getattr.3, mq_notify.3, mq_open.3, mq_receive.3, mq_send.3, mq_unlink.3, mtrace.3, nan.3, newlocale.3, nextafter.3, nextup.3, nl_langinfo.3, ntp_gettime.3, on_exit.3, open_memstream.3, opendir.3, openpty.3, perror.3, popen.3, posix_fallocate.3, posix_madvise.3, posix_memalign.3, posix_openpt.3, posix_spawn.3, pow.3, pow10.3, printf.3, profil.3, psignal.3, pthread_attr_init.3, pthread_attr_setaffinity_np.3, pthread_attr_setdetachstate.3, pthread_attr_setguardsize.3, pthread_attr_setinheritsched.3, pthread_attr_setschedparam.3, pthread_attr_setschedpolicy.3, pthread_attr_setscope.3, pthread_attr_setsigmask_np.3, pthread_attr_setstack.3, pthread_attr_setstackaddr.3, pthread_attr_setstacksize.3, pthread_cancel.3, pthread_cleanup_push.3, pthread_cleanup_push_defer_np.3, pthread_create.3, pthread_detach.3, pthread_equal.3, pthread_exit.3, pthread_getattr_default_np.3, pthread_getattr_np.3, pthread_getcpuclockid.3, pthread_join.3, pthread_kill.3, pthread_kill_other_threads_np.3, pthread_mutex_consistent.3, pthread_mutexattr_getpshared.3, pthread_mutexattr_setrobust.3, pthread_rwlockattr_setkind_np.3, pthread_self.3, pthread_setaffinity_np.3, pthread_setcancelstate.3, pthread_setconcurrency.3, pthread_setname_np.3, pthread_setschedparam.3, pthread_setschedprio.3, pthread_sigmask.3, pthread_sigqueue.3, pthread_spin_init.3, pthread_spin_lock.3, pthread_testcancel.3, pthread_tryjoin_np.3, pthread_yield.3, ptsname.3, putenv.3, putgrent.3, putpwent.3, puts.3, putwchar.3, qecvt.3, qsort.3, raise.3, rand.3, random.3, random_r.3, rcmd.3, re_comp.3, readdir.3, readdir_r.3, realpath.3, regex.3, remainder.3, remove.3, remquo.3, resolver.3, rewinddir.3, rexec.3, rint.3, round.3, rpc.3, rpmatch.3, rtime.3, rtnetlink.3, scalb.3, scalbln.3, scandir.3, scanf.3, sched_getcpu.3, seekdir.3, sem_close.3, sem_destroy.3, sem_getvalue.3, sem_init.3, sem_open.3, sem_post.3, sem_unlink.3, sem_wait.3, setaliasent.3, setbuf.3, setenv.3, setjmp.3, setlocale.3, setlogmask.3, setnetgrent.3, shm_open.3, siginterrupt.3, signbit.3, significand.3, sigpause.3, sigqueue.3, sigset.3, sigsetops.3, sigvec.3, sigwait.3, sin.3, sincos.3, sinh.3, sleep.3, slist.3, sockatmark.3, sqrt.3, stailq.3, statvfs.3, stdarg.3, stdio.3, stdio_ext.3, stpcpy.3, stpncpy.3, strcasecmp.3, strcat.3, strchr.3, strcmp.3, strcoll.3, strcpy.3, strdup.3, strerror.3, strfmon.3, strfromd.3, strfry.3, strftime.3, string.3, strlen.3, strnlen.3, strpbrk.3, strptime.3, strsep.3, strsignal.3, strspn.3, strstr.3, strtod.3, strtoimax.3, strtok.3, strtol.3, strtoul.3, strverscmp.3, strxfrm.3, swab.3, sysconf.3, syslog.3, system.3, sysv_signal.3, tailq.3, tan.3, tanh.3, tcgetpgrp.3, tcgetsid.3, telldir.3, tempnam.3, termios.3, tgamma.3, timegm.3, timeradd.3, tmpfile.3, tmpnam.3, toascii.3, toupper.3, towctrans.3, towlower.3, towupper.3, trunc.3, tsearch.3, ttyname.3, ttyslot.3, tzset.3, ualarm.3, ulimit.3, undocumented.3, ungetwc.3, unlocked_stdio.3, unlockpt.3, updwtmp.3, uselocale.3, usleep.3, wcpcpy.3, wcpncpy.3, wcrtomb.3, wcscasecmp.3, wcscat.3, wcschr.3, wcscmp.3, wcscpy.3, wcscspn.3, wcsdup.3, wcslen.3, wcsncasecmp.3, wcsncat.3, wcsncmp.3, wcsncpy.3, wcsnlen.3, wcsnrtombs.3, wcspbrk.3, wcsrchr.3, wcsrtombs.3, wcsspn.3, wcsstr.3, wcstoimax.3, wcstok.3, wcstombs.3, wcswidth.3, wctob.3, wctomb.3, wctrans.3, wctype.3, wcwidth.3, wmemchr.3, wmemcmp.3, wmemcpy.3, wmemmove.3, wmemset.3, wordexp.3, wprintf.3, xcrypt.3, xdr.3, y0.3, cciss.4, console_codes.4, dsp56k.4, hpsa.4, initrd.4, loop.4, lp.4, msr.4, random.4, rtc.4, smartpqi.4, veth.4, wavelan.4, acct.5, core.5, elf.5, hosts.5, locale.5, proc.5, resolv.conf.5, rpc.5, slabinfo.5, sysfs.5, tmpfs.5, utmp.5, address_families.7, aio.7, attributes.7, bootparam.7, capabilities.7, cgroups.7, complex.7, ddp.7, environ.7, epoll.7, fanotify.7, feature_test_macros.7, hier.7, inode.7, inotify.7, ip.7, ipv6.7, keyrings.7, locale.7, man-pages.7, man.7, math_error.7, mount_namespaces.7, namespaces.7, netdevice.7, netlink.7, numa.7, packet.7, pkeys.7, pthreads.7, queue.7, raw.7, rtnetlink.7, sched.7, session-keyring.7, shm_overview.7, sigevent.7, signal-safety.7, signal.7, sock_diag.7, socket.7, spufs.7, symlink.7, system_data_types.7, tcp.7, time_namespaces.7, udp.7, udplite.7, unicode.7, unix.7, uri.7, user_namespaces.7, vdso.7, vsock.7, x25.7, iconvconfig.8, ld.so.8, ldconfig.8, sln.8, tzselect.8: tstamp
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2021-03-21 23:15:34 +00:00
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.TH TMPFS 5 2021-03-22 "Linux" "Linux Programmer's Manual"
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2016-11-07 14:44:24 +00:00
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.SH NAME
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tmpfs \- a virtual memory filesystem
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.SH DESCRIPTION
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The
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.B tmpfs
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facility allows the creation of filesystems whose contents reside
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in virtual memory.
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Since the files on such filesystems typically reside in RAM,
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file access is extremely fast.
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cpuid.4, fd.4, full.4, initrd.4, lirc.4, msr.4, null.4, vcs.4, charmap.5, core.5, dir_colors.5, filesystems.5, gai.conf.5, hosts.equiv.5, locale.5, motd.5, networks.5, nscd.conf.5, nss.5, proc.5, protocols.5, repertoiremap.5, services.5, tmpfs.5, ttytype.5, intro.8, nscd.8: ffix
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2017-08-17 22:59:55 +00:00
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.PP
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2016-11-07 14:44:24 +00:00
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The filesystem is automatically created when mounting
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a filesystem with the type
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.BR tmpfs
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via a command such as the following:
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2017-08-15 14:15:21 +00:00
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.PP
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.in +4n
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.EX
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2020-07-01 23:12:18 +00:00
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$ sudo mount \-t tmpfs \-o size=10M tmpfs /mnt/mytmpfs
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2017-08-15 14:15:21 +00:00
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.EE
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.in
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.PP
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2016-11-07 14:44:24 +00:00
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A
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.B tmpfs
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filesystem has the following properties:
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.IP * 3
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The filesystem can employ swap space when physical memory pressure
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demands it.
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.IP *
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The filesystem consumes only as much physical memory and swap space
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as is required to store the current contents of the filesystem.
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.IP *
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During a remount operation
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.RI ( "mount\ \-o\ remount" ),
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the filesystem size can be changed
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(without losing the existing contents of the filesystem).
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.PP
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If a
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.B tmpfs
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filesystem is unmounted, its contents are discarded (lost).
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2018-01-27 09:59:28 +00:00
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.\" See mm/shmem.c:shmem_parse_options for options it supports.
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.SS Mount options
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The
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.B tmpfs
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filesystem supports the following mount options:
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.TP
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.BR size "=\fIbytes\fP"
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Specify an upper limit on the size of the filesystem.
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The size is given in bytes, and rounded up to entire pages.
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2018-02-03 16:04:35 +00:00
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.IP
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2018-01-27 09:59:28 +00:00
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The size may have a
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.BR k ,
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.BR m ,
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or
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.B g
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2021-01-09 10:14:08 +00:00
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suffix for Ki, Mi, Gi (binary kilo (kibi), binary mega (mebi), and binary giga
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2018-01-27 09:59:28 +00:00
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(gibi)).
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2018-02-03 16:04:35 +00:00
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.IP
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2018-01-27 09:59:28 +00:00
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The size may also have a % suffix to limit this instance to a percentage of
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physical RAM.
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2018-02-03 16:04:35 +00:00
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.IP
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The default, when neither
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.B size
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nor
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.B nr_blocks
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is specified, is
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.IR size=50% .
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2018-01-27 09:59:28 +00:00
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.TP
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.BR nr_blocks "=\fIblocks\fP"
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The same as
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.BR size ,
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2018-02-03 16:04:35 +00:00
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but in blocks of
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.BR PAGE_CACHE_SIZE .
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.IP
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2018-01-27 09:59:28 +00:00
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Blocks may be specified with
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.BR k ,
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.BR m ,
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or
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.B g
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suffixes like
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.BR size ,
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but not a % suffix.
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.TP
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.BR nr_inodes "=\fIinodes\fP"
|
|
|
|
The maximum number of inodes for this instance.
|
|
|
|
The default is half of the number of your physical RAM pages, or (on a
|
|
|
|
machine with highmem) the number of lowmem RAM pages, whichever is smaller.
|
2018-02-03 16:04:35 +00:00
|
|
|
.IP
|
2018-01-27 09:59:28 +00:00
|
|
|
Inodes may be specified with
|
|
|
|
.BR k ,
|
|
|
|
.BR m ,
|
|
|
|
or
|
|
|
|
.B g
|
|
|
|
suffixes like
|
|
|
|
.BR size ,
|
|
|
|
but not a % suffix.
|
|
|
|
.TP
|
|
|
|
.BR mode "=\fImode\fP"
|
|
|
|
Set initial permissions of the root directory.
|
|
|
|
.TP
|
|
|
|
.BR gid "=\fIgid\fP (since Linux 2.5.7)"
|
|
|
|
.\" Technically this is also in some version of Linux 2.4.
|
|
|
|
.\" commit 099445b489625b80b1d6687c9b6072dbeaca4096
|
|
|
|
Set the initial group ID of the root directory.
|
|
|
|
.TP
|
|
|
|
.BR uid "=\fIuid\fP (since Linux 2.5.7)"
|
|
|
|
.\" Technically this is also in some version of Linux 2.4.
|
|
|
|
.\" commit 099445b489625b80b1d6687c9b6072dbeaca4096
|
|
|
|
Set the initial user ID of the root directory.
|
|
|
|
.TP
|
2018-02-04 07:42:09 +00:00
|
|
|
.BR huge "=\fIhuge_option\fR (since Linux 4.7.0)"
|
2018-01-27 09:59:28 +00:00
|
|
|
.\" commit 5a6e75f8110c97e2a5488894d4e922187e6cb343
|
|
|
|
Set the huge table memory allocation policy for all files in this instance (if
|
2018-02-03 16:04:35 +00:00
|
|
|
.B CONFIG_TRANSPARENT_HUGE_PAGECACHE
|
|
|
|
is enabled).
|
2018-02-04 07:42:09 +00:00
|
|
|
.IP
|
|
|
|
The
|
|
|
|
.I huge_option
|
|
|
|
value is one of the following:
|
|
|
|
.RS
|
|
|
|
.TP
|
|
|
|
.B never
|
2018-02-04 08:25:26 +00:00
|
|
|
Do not allocate huge pages.
|
|
|
|
This is the default.
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
|
|
|
.B always
|
2018-02-04 08:25:26 +00:00
|
|
|
Attempt to allocate huge pages every time a new page is needed.
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
|
|
|
.B within_size
|
2018-02-04 08:25:26 +00:00
|
|
|
Only allocate huge page if it will be fully within
|
|
|
|
.IR i_size .
|
|
|
|
Also respect
|
|
|
|
.BR fadvise (2)/ madvise (2)
|
|
|
|
hints
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
|
|
|
.B advise
|
2018-02-04 08:25:26 +00:00
|
|
|
Only allocate huge pages if requested with
|
|
|
|
.BR fadvise (2)/ madvise (2).
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
|
|
|
.B deny
|
2018-02-04 08:25:26 +00:00
|
|
|
For use in emergencies, to force the huge option off from all mounts.
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
|
|
|
.B force
|
2018-02-04 08:25:26 +00:00
|
|
|
Force the huge option on for all mounts; useful for testing.
|
2018-02-04 07:42:09 +00:00
|
|
|
.RE
|
2018-01-27 09:59:28 +00:00
|
|
|
.TP
|
2018-02-04 07:42:09 +00:00
|
|
|
.BR mpol "=\fImpol_option\fR (since Linux 2.6.15)"
|
2018-01-27 09:59:28 +00:00
|
|
|
.\" commit 7339ff8302fd70aabf5f1ae26e0c4905fa74a495
|
|
|
|
Set the NUMA memory allocation policy for all files in this instance (if
|
2018-02-03 16:04:35 +00:00
|
|
|
.B CONFIG_NUMA
|
|
|
|
is enabled).
|
2018-02-04 07:42:09 +00:00
|
|
|
.IP
|
|
|
|
The
|
|
|
|
.I mpol_option
|
|
|
|
value is one of the following:
|
|
|
|
.RS
|
|
|
|
.TP
|
|
|
|
.B default
|
2018-02-04 08:02:25 +00:00
|
|
|
Use the process allocation policy (see
|
|
|
|
.BR set_mempolicy (2)).
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
2018-02-04 08:02:25 +00:00
|
|
|
.BR prefer ":\fInode\fP"
|
|
|
|
Preferably allocate memory from the given
|
|
|
|
.IR node .
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
2018-02-04 08:02:25 +00:00
|
|
|
.BR bind ":\fInodelist\fP"
|
|
|
|
Allocate memory only from nodes in
|
|
|
|
.IR nodelist .
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
|
|
|
.B interleave
|
2018-02-04 08:02:25 +00:00
|
|
|
Allocate from each node in turn.
|
2018-02-04 07:42:09 +00:00
|
|
|
.TP
|
2018-02-04 08:02:25 +00:00
|
|
|
.BR interleave ":\fInodelist\fP"
|
|
|
|
Allocate from each node of
|
|
|
|
.I in
|
|
|
|
turn.
|
2018-02-04 08:08:07 +00:00
|
|
|
.TP
|
|
|
|
.B local
|
|
|
|
Preferably allocate memory from the local node.
|
2018-02-04 07:42:09 +00:00
|
|
|
.RE
|
2018-02-04 08:02:25 +00:00
|
|
|
.IP
|
|
|
|
In the above,
|
|
|
|
.I nodelist
|
|
|
|
is a comma-separated list of decimal numbers and ranges
|
|
|
|
that specify NUMA nodes.
|
|
|
|
A range is a pair of hyphen-separated decimal numbers,
|
|
|
|
the smallest and largest node numbers in the range.
|
|
|
|
For example,
|
|
|
|
.IR mpol=bind:0\-3,5,7,9\-15 .
|
2016-11-07 14:44:24 +00:00
|
|
|
.SH VERSIONS
|
|
|
|
The
|
|
|
|
.B tmpfs
|
|
|
|
facility was added in Linux 2.4, as a successor to the older
|
|
|
|
.B ramfs
|
|
|
|
facility, which did not provide limit checking or
|
|
|
|
allow for the use of swap space.
|
|
|
|
.SH NOTES
|
2017-03-30 15:29:41 +00:00
|
|
|
In order for user-space tools and applications to create
|
2016-11-07 14:44:24 +00:00
|
|
|
.B tmpfs
|
|
|
|
filesystems, the kernel must be configured with the
|
|
|
|
.B CONFIG_TMPFS
|
|
|
|
option.
|
cpuid.4, fd.4, full.4, initrd.4, lirc.4, msr.4, null.4, vcs.4, charmap.5, core.5, dir_colors.5, filesystems.5, gai.conf.5, hosts.equiv.5, locale.5, motd.5, networks.5, nscd.conf.5, nss.5, proc.5, protocols.5, repertoiremap.5, services.5, tmpfs.5, ttytype.5, intro.8, nscd.8: ffix
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2017-08-17 22:59:55 +00:00
|
|
|
.PP
|
2017-03-17 18:41:16 +00:00
|
|
|
The
|
|
|
|
.BR tmpfs
|
|
|
|
filesystem supports extended attributes (see
|
|
|
|
.BR xattr (7)),
|
|
|
|
but
|
|
|
|
.I user
|
|
|
|
extended attributes are not permitted.
|
cpuid.4, fd.4, full.4, initrd.4, lirc.4, msr.4, null.4, vcs.4, charmap.5, core.5, dir_colors.5, filesystems.5, gai.conf.5, hosts.equiv.5, locale.5, motd.5, networks.5, nscd.conf.5, nss.5, proc.5, protocols.5, repertoiremap.5, services.5, tmpfs.5, ttytype.5, intro.8, nscd.8: ffix
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2017-08-17 22:59:55 +00:00
|
|
|
.PP
|
2016-11-07 14:44:24 +00:00
|
|
|
An internal shared memory filesystem is used for
|
|
|
|
System V shared memory
|
2017-07-04 23:02:01 +00:00
|
|
|
.RB ( shmget (2))
|
2016-11-07 14:44:24 +00:00
|
|
|
and shared anonymous mappings
|
|
|
|
.RB ( mmap (2)
|
|
|
|
with the
|
|
|
|
.B MAP_SHARED
|
|
|
|
and
|
|
|
|
.BR MAP_ANONYMOUS
|
|
|
|
flags).
|
|
|
|
This filesystem is available regardless of whether
|
|
|
|
the kernel was configured with the
|
|
|
|
.B CONFIG_TMPFS
|
|
|
|
option.
|
cpuid.4, fd.4, full.4, initrd.4, lirc.4, msr.4, null.4, vcs.4, charmap.5, core.5, dir_colors.5, filesystems.5, gai.conf.5, hosts.equiv.5, locale.5, motd.5, networks.5, nscd.conf.5, nss.5, proc.5, protocols.5, repertoiremap.5, services.5, tmpfs.5, ttytype.5, intro.8, nscd.8: ffix
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2017-08-17 22:59:55 +00:00
|
|
|
.PP
|
2016-11-07 14:44:24 +00:00
|
|
|
A
|
|
|
|
.B tmpfs
|
|
|
|
filesystem mounted at
|
|
|
|
.IR /dev/shm
|
2018-02-04 09:05:14 +00:00
|
|
|
is used for the implementation of POSIX shared memory
|
2016-11-07 14:44:24 +00:00
|
|
|
.RB ( shm_overview (7))
|
|
|
|
and POSIX semaphores
|
|
|
|
.RB ( sem_overview (7)).
|
cpuid.4, fd.4, full.4, initrd.4, lirc.4, msr.4, null.4, vcs.4, charmap.5, core.5, dir_colors.5, filesystems.5, gai.conf.5, hosts.equiv.5, locale.5, motd.5, networks.5, nscd.conf.5, nss.5, proc.5, protocols.5, repertoiremap.5, services.5, tmpfs.5, ttytype.5, intro.8, nscd.8: ffix
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2017-08-17 22:59:55 +00:00
|
|
|
.PP
|
2016-11-07 14:44:24 +00:00
|
|
|
The amount of memory consumed by all
|
|
|
|
.B tmpfs
|
|
|
|
filesystems is shown in the
|
|
|
|
.I Shmem
|
|
|
|
field of
|
|
|
|
.IR /proc/meminfo
|
|
|
|
and in the
|
|
|
|
.I shared
|
|
|
|
field displayed by
|
|
|
|
.BR free (1).
|
cpuid.4, fd.4, full.4, initrd.4, lirc.4, msr.4, null.4, vcs.4, charmap.5, core.5, dir_colors.5, filesystems.5, gai.conf.5, hosts.equiv.5, locale.5, motd.5, networks.5, nscd.conf.5, nss.5, proc.5, protocols.5, repertoiremap.5, services.5, tmpfs.5, ttytype.5, intro.8, nscd.8: ffix
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2017-08-17 22:59:55 +00:00
|
|
|
.PP
|
2016-11-07 14:44:24 +00:00
|
|
|
The
|
|
|
|
.B tmpfs
|
|
|
|
facility was formerly called
|
|
|
|
.BR shmfs .
|
|
|
|
.SH SEE ALSO
|
|
|
|
.BR df (1),
|
|
|
|
.BR du (1),
|
2017-05-26 12:38:55 +00:00
|
|
|
.BR memfd_create (2),
|
|
|
|
.BR mmap (2),
|
2018-02-04 08:43:55 +00:00
|
|
|
.BR set_mempolicy (2),
|
2017-05-26 12:38:55 +00:00
|
|
|
.BR shm_open (3),
|
2016-11-07 14:44:24 +00:00
|
|
|
.BR mount (8)
|
|
|
|
.PP
|
2018-02-04 08:43:24 +00:00
|
|
|
The kernel source files
|
|
|
|
.IR Documentation/filesystems/tmpfs.txt
|
|
|
|
and
|
2021-01-21 08:29:38 +00:00
|
|
|
.IR Documentation/admin\-guide/mm/transhuge.rst .
|