but its operation can be controlled by writing one of the
following integer strings to the file
.IR /proc/sys/net/core/bpf_jit_enable :
-.IP 0 3
+.TP
+.B 0
Disable JIT compilation (default).
-.IP 1
+.TP
+.B 1
Normal compilation.
-.IP 2
+.TP
+.B 2
Debugging mode.
The generated opcodes are dumped in hexadecimal into the kernel log.
These opcodes can then be disassembled using the program
which governs what
screen blanking does:
.RS
-.IP 0: 3
+.TP
+.B 0
Screen blanking is disabled.
-.IP 1:
+.TP
+.B 1
The current video adapter
register settings are saved, then the controller is programmed to turn off
the vertical synchronization pulses.
This puts the monitor into "standby" mode.
If your monitor has an Off_Mode timer, then
it will eventually power down by itself.
-.IP 2:
+.TP
+.B 2
The current settings are saved, then both the vertical and horizontal
synchronization pulses are turned off.
This puts the monitor into "off" mode.
.I v2
are the addresses of appropriate resources, then the return value
is one of the following:
-.RS 4
-.IP 0 4
+.RS
+.TP
+.B 0
.I v1
is equal to
.IR v2 ;
in other words, the two processes share the resource.
-.IP 1
+.TP
+.B 1
.I v1
is less than
.IR v2 .
-.IP 2
+.TP
+.B 2
.I v1
is greater than
.IR v2 .
-.IP 3
+.TP
+.B 3
.I v1
is not equal to
.IR v2 ,
.IP
The possible values of this field are the following:
.RS
-.IP 0 3
+.TP
+.B 0
.B SAMPLE_IP
can have arbitrary skid.
-.IP 1
+.TP
+.B 1
.B SAMPLE_IP
must have constant skid.
-.IP 2
+.TP
+.B 2
.B SAMPLE_IP
requested to have 0 skid.
-.IP 3
+.TP
+.B 3
.B SAMPLE_IP
must have 0 skid.
See also the description of
.IP
.PD 0
.RS
-.IP 2 4
+.TP
+.B 2
allow only user-space measurements (default since Linux 4.6).
.\" default changed in commit 0161028b7c8aebef64194d3d73e43bc3b53b5c66
-.IP 1
+.TP
+.B 1
allow both kernel and user measurements (default before Linux 4.6).
-.IP 0
+.TP
+.B 0
allow access to CPU-specific data but not raw tracepoint samples.
-.IP \-1
+.TP
+.B \-1
no restrictions.
.RE
.PD
kernel buffer, implemented within the kernel using the same type
of buffer that is used for a pipe.
In overview, these system calls perform the following tasks:
-.IP \(bu 2
+.TP
.BR splice ()
moves data from the buffer to an arbitrary file descriptor, or vice versa,
or from one buffer to another.
-.IP \(bu
+.TP
.BR tee (2)
"copies" the data from one buffer to another.
-.IP \(bu
+.TP
.BR vmsplice (2)
"copies" data from user space into the buffer.
.PP
.\"
.\"
.SS "Architecture-specific details: Alpha"
-.IP * 3
+.TP
.BR getxgid (2)
returns a pair of GID and effective GID via registers
\fBr0\fP and \fBr20\fP; it is provided
instead of
\fBgetgid\fP(2) and \fBgetegid\fP(2).
-.IP *
+.TP
.BR getxpid (2)
returns a pair of PID and parent PID via registers
\fBr0\fP and \fBr20\fP; it is provided instead of
\fBgetpid\fP(2) and \fBgetppid\fP(2).
-.IP *
+.TP
.BR old_adjtimex (2)
is a variant of \fBadjtimex\fP(2) that uses \fIstruct timeval32\fP,
for compatibility with OSF/1.
-.IP *
+.TP
.BR getxuid (2)
returns a pair of GID and effective GID via registers
\fBr0\fP and \fBr20\fP; it is provided instead of
\fBgetuid\fP(2) and \fBgeteuid\fP(2).
-.IP *
+.TP
.BR sethae (2)
is used for configuring the Host Address Extension register on
low-cost Alphas in order to access address space beyond first 27 bits.
.BR timer_create ()
are commonly known as "POSIX (interval) timers".
The POSIX timers API consists of the following interfaces:
-.IP * 3
-.BR timer_create ():
+.TP
+.BR timer_create ()
Create a timer.
-.IP *
-.BR timer_settime (2):
+.TP
+.BR timer_settime (2)
Arm (start) or disarm (stop) a timer.
-.IP *
-.BR timer_gettime (2):
+.TP
+.BR timer_gettime (2)
Fetch the time remaining until the next expiration of a timer,
along with the interval setting of the timer.
-.IP *
-.BR timer_getoverrun (2):
+.TP
+.BR timer_getoverrun (2)
Return the overrun count for the last timer expiration.
-.IP *
-.BR timer_delete (2):
+.TP
+.BR timer_delete (2)
Disarm and delete a timer.
.PP
Since Linux 3.10, the
The value of
.I pid
can be:
-.IP "< \-1"
+.TP
+.RB "< " \-1
meaning wait for any child process whose process group ID is
equal to the absolute value of
.IR pid .
-.IP \-1
+.TP
+.B \-1
meaning wait for any child process.
-.IP 0
+.TP
+.B 0
meaning wait for any child process whose process group ID is
equal to that of the calling process at the time of the call to
.BR waitpid ().
-.IP "> 0"
+.TP
+.RB "> " 0
meaning wait for the child whose process ID is equal to the
value of
.IR pid .
and
.I id
arguments select the child(ren) to wait for, as follows:
-.IP "\fIidtype\fP == \fBP_PID\fP"
+.TP
+.IR idtype " == " \fBP_PID\fP
Wait for the child whose process ID matches
.IR id .
-.IP "\fIidtype\fP == \fBP_PIDFD\fP (since Linux 5.4)"
+.TP
+.IR idtype " == " \fBP_PIDFD\fP " (since Linux 5.4)"
.\" commit 3695eae5fee0605f316fbaad0b9e3de791d7dfaf
Wait for the child referred to by the PID file descriptor specified in
.IR id .
(See
.BR pidfd_open (2)
for further information on PID file descriptors.)
-.IP "\fIidtype\fP == \fBP_PGID\fP"
+.TP
+.IR idtype " == " \fBP_PGID\fP
Wait for any child whose process group ID matches
.IR id .
Since Linux 5.4,
.I id
is zero, then wait for any child that is in the same process group
as the caller's process group at the time of the call.
-.IP "\fIidtype\fP == \fBP_ALL\fP"
+.TP
+.IR idtype " == " \fBP_ALL\fP
Wait for any child;
.I id
is ignored.
throughput by causing system resources to be used more
efficiently, especially in contention situations.
The available unprivileged states are covered by the following functions:
-.IP * 3
+.TP
.BR __ppc_set_ppr_med ()
sets the Program Priority Register value to
.I medium
(default).
-.IP *
+.TP
.BR __ppc_set_ppr_very_low ()
sets the Program Priority Register value to
.IR "very low" .
-.IP *
+.TP
.BR __ppc_set_ppr_low ()
sets the Program Priority Register value to
.IR low .
-.IP *
+.TP
.BR __ppc_set_ppr_med_low ()
sets the Program Priority Register value to
.IR "medium low" .
.I medium high
may also be set during certain time intervals by problem-state (unprivileged)
programs, with the following function:
-.IP * 3
+.TP
.BR __ppc_set_ppr_med_high ()
sets the Program Priority to
.IR "medium high" .
structure.)
.SH RETURN VALUE
This function returns one of the following:
-.IP * 3
-.BR EINPROGRESS ,
+.TP
+.B EINPROGRESS
if the request has not been
completed yet.
-.IP *
-.BR ECANCELED ,
+.TP
+.B ECANCELED
if the request was canceled.
-.IP *
-0, if the request completed successfully.
-.IP *
+.TP
+.B 0
+if the request completed successfully.
+.TP
+.RB "> " 0
A positive error number, if the asynchronous I/O operation failed.
This is the same value that would have been stored in the
.I errno
.I cmsghdr
structures should never be accessed directly.
Instead, use only the following macros:
-.IP * 3
+.TP
.BR CMSG_FIRSTHDR ()
returns a pointer to the first
.I cmsghdr
It returns NULL if there isn't enough space for a
.I cmsghdr
in the buffer.
-.IP *
+.TP
.BR CMSG_NXTHDR ()
returns the next valid
.I cmsghdr
that buffer should first be zero-initialized
to ensure the correct operation of
.BR CMSG_NXTHDR ().
-.IP *
+.TP
.BR CMSG_ALIGN (),
given a length, returns it including the required alignment.
This is a
constant expression.
-.IP *
+.TP
.BR CMSG_SPACE ()
returns the number of bytes an ancillary element with payload of the
passed data length occupies.
This is a constant expression.
-.IP *
+.TP
.BR CMSG_DATA ()
returns a pointer to the data portion of a
.IR cmsghdr .
but should instead use
.BR memcpy (3)
to copy data to or from a suitably declared object.
-.IP *
+.TP
.BR CMSG_LEN ()
returns the value to store in the
.I cmsg_len
.SS List of error names
In the list of the symbolic error names below,
various names are marked as follows:
-.IP * 3
-.IR POSIX.1-2001 :
+.TP
+.IR POSIX.1-2001
The name is defined by POSIX.1-2001,
and is defined in later POSIX.1 versions, unless otherwise indicated.
-.IP *
-.IR POSIX.1-2008 :
+.TP
+.IR POSIX.1-2008
The name is defined in POSIX.1-2008,
but was not present in earlier POSIX.1 standards.
-.IP *
-.IR C99 :
+.TP
+.IR C99
The name is defined by C99.
.PP
Below is a list of the symbolic error names that are defined on Linux:
which indicates the implementation-defined rounding
behavior for floating-point addition.
This identifier has one of the following values:
-.IP \-1
+.TP
+.B \-1
The rounding mode is not determinable.
-.IP 0
+.TP
+.B 0
Rounding is toward 0.
-.IP 1
+.TP
+.B 1
Rounding is toward nearest number.
-.IP 2
+.TP
+.B 2
Rounding is toward positive infinity.
-.IP 3
+.TP
+.B 3
Rounding is toward negative infinity.
.PP
Other values represent machine-dependent, nonstandard rounding modes.
the following numeric values are meaningful for
.BR M_CHECK_ACTION :
.RS 12
-.IP 0 3
+.TP
+.B 0
Ignore error conditions; continue execution (with undefined results).
-.IP 1
+.TP
+.B 1
Print a detailed error message and continue execution.
-.IP 2
+.TP
+.B 2
Abort the program.
-.IP 3
+.TP
+.B 3
Print detailed error message, stack trace, and memory mappings,
and abort the program.
-.IP 5
+.TP
+.B 5
Print a simple error message and continue execution.
-.IP 7
+.TP
+.B 7
Print simple error message, stack trace, and memory mappings,
and abort the program.
.RE
differs only on the point just described.
.PP
The remaining arguments to these two functions are as follows:
-.IP * 3
-The
+.TP
.I pid
-argument points to a buffer that is used to return the process ID
+points to a buffer that is used to return the process ID
of the new child process.
-.IP *
-The
+.TP
.I file_actions
-argument points to a
+points to a
.I "spawn file actions object"
that specifies file-related actions to be performed in the child
between the
and the
.BR posix_spawn_file_actions_* ()
functions.
-.IP *
-The
+.TP
.I attrp
-argument points to an
+points to an
.I attributes objects
that specifies various attributes of the created child process.
This object is initialized and populated before the
and the
.BR posix_spawnattr_* ()
functions.
-.IP *
-The
+.TP
.I argv
-and
+.TQ
.I envp
-arguments specify the argument list and environment for the program
+specify the argument list and environment for the program
that is executed in the child process, as for
.BR execve (2).
.PP
required from the underlying hardware that is not available) from the
\fItermios\fP structure referred to by \fItermios_p\fP.
\fIoptional_actions\fP specifies when the changes take effect:
-.IP \fBTCSANOW\fP
+.TP
+.B TCSANOW
the change occurs immediately.
-.IP \fBTCSADRAIN\fP
+.TP
+.B TCSADRAIN
the change occurs after all output written to
.I fd
has been transmitted.
This option should be used when changing
parameters that affect output.
-.IP \fBTCSAFLUSH\fP
+.TP
+.B TCSAFLUSH
the change occurs after all output written to the object referred by
.I fd
has been transmitted, and all input that has been received but not read
but not transmitted, or data received but not read, depending on the
value of
.IR queue_selector :
-.IP \fBTCIFLUSH\fP
+.TP
+.B TCIFLUSH
flushes data received but not read.
-.IP \fBTCOFLUSH\fP
+.TP
+.B TCOFLUSH
flushes data written but not transmitted.
-.IP \fBTCIOFLUSH\fP
+.TP
+.B TCIOFLUSH
flushes both data received but not read, and data written but not
transmitted.
.PP
.IR fd ,
depending on the value of
.IR action :
-.IP \fBTCOOFF\fP
+.TP
+.B TCOOFF
suspends output.
-.IP \fBTCOON\fP
+.TP
+.B TCOON
restarts suspended output.
-.IP \fBTCIOFF\fP
+.TP
+.B TCIOFF
transmits a STOP character, which stops the terminal device from
transmitting data to the system.
-.IP \fBTCION\fP
+.TP
+.B TCION
transmits a START character, which starts the terminal device
transmitting data to the system.
.PP
returns the output baud rate stored in the \fItermios\fP structure.
.PP
All other functions return:
-.IP 0
+.TP
+.B 0
on success.
-.IP \-1
+.TP
+.B \-1
on failure and set
.I errno
to indicate the error.
.BR ioctl (2)
calls are used to control the
\fIdsp56k\fP device:
-.IP \fBDSP56K_UPLOAD\fP
+.TP
+.B DSP56K_UPLOAD
resets the DSP56001 and uploads a program.
The third
.BR ioctl (2)
argument must be a pointer to a \fIstruct dsp56k_upload\fP with members
\fIbin\fP pointing to a DSP56001 binary program, and \fIlen\fP set to
the length of the program, counted in 24-bit words.
-.IP \fBDSP56K_SET_TX_WSIZE\fP
+.TP
+.B DSP56K_SET_TX_WSIZE
sets the transmit word size.
Allowed values are in the range 1 to 4,
and is the number of bytes that will be sent at a time to the
These data quantities will either be padded with bytes containing zero,
or truncated to fit the native 24-bit data format of the
DSP56001.
-.IP \fBDSP56K_SET_RX_WSIZE\fP
+.TP
+.B DSP56K_SET_RX_WSIZE
sets the receive word size.
Allowed values are in the range 1 to 4,
and is the number of bytes that will be received at a time from the
DSP56001.
These data quantities will either truncated, or padded with
a null byte (\(aq\e0\(aq) to fit the native 24-bit data format of the DSP56001.
-.IP \fBDSP56K_HOST_FLAGS\fP
+.TP
+.B DSP56K_HOST_FLAGS
read and write the host flags.
The host flags are four
general-purpose bits that can be read by both the hosting computer and
to the host flags.
The state of all host flags will be returned in
the lower four bits of the \fIstatus\fP member.
-.IP \fBDSP56K_HOST_CMD\fP
+.TP
+.B DSP56K_HOST_CMD
sends a host command.
Allowed values are in the range 0 to 31, and is a
user-defined command handled by the program running in the DSP56001.
The following
.BR ioctl (2)
calls are supported by \fBfd\fP devices:
-.IP \fBFDCLRPRM\fP
+.TP
+.B FDCLRPRM
clears the media information of a drive (geometry of disk in drive).
-.IP \fBFDSETPRM\fP
+.TP
+.B FDSETPRM
sets the media information of a drive.
The media information will be
lost when the media is changed.
-.IP \fBFDDEFPRM\fP
+.TP
+.B FDDEFPRM
sets the media information of a drive (geometry of disk in drive).
The media information will not be lost when the media is changed.
This will disable autodetection.
In order to reenable autodetection, you
have to issue an \fBFDCLRPRM\fP.
-.IP \fBFDGETDRVTYP\fP
+.TP
+.B FDGETDRVTYP
returns the type of a drive (name parameter).
For formats which work
in several drive types, \fBFDGETDRVTYP\fP returns a name which is
appropriate for the oldest drive type which supports this format.
-.IP \fBFDFLUSH\fP
+.TP
+.B FDFLUSH
invalidates the buffer cache for the given drive.
-.IP \fBFDSETMAXERRS\fP
+.TP
+.B FDSETMAXERRS
sets the error thresholds for reporting errors, aborting the operation,
recalibrating, resetting, and reading sector by sector.
-.IP \fBFDSETMAXERRS\fP
+.TP
+.B FDSETMAXERRS
gets the current error thresholds.
-.IP \fBFDGETDRVTYP\fP
+.TP
+.B FDGETDRVTYP
gets the internal name of the drive.
-.IP \fBFDWERRORCLR\fP
+.TP
+.B FDWERRORCLR
clears the write error statistics.
-.IP \fBFDWERRORGET\fP
+.TP
+.B FDWERRORGET
reads the write error statistics.
These include the total number of
write errors, the location and disk of the first write error, and the
location and disk of the last write error.
Disks are identified by a
generation number which is incremented at (almost) each disk change.
-.IP \fBFDTWADDLE\fP
+.TP
+.B FDTWADDLE
Switch the drive motor off for a few microseconds.
This might be
needed in order to access a disk whose sectors are too close together.
-.IP \fBFDSETDRVPRM\fP
+.TP
+.B FDSETDRVPRM
sets various drive parameters.
-.IP \fBFDGETDRVPRM\fP
+.TP
+.B FDGETDRVPRM
reads these parameters back.
-.IP \fBFDGETDRVSTAT\fP
+.TP
+.B FDGETDRVSTAT
gets the cached drive state (disk changed, write protected et al.)
-.IP \fBFDPOLLDRVSTAT\fP
+.TP
+.B FDPOLLDRVSTAT
polls the drive and return its state.
-.IP \fBFDGETFDCSTAT\fP
+.TP
+.B FDGETFDCSTAT
gets the floppy controller state.
-.IP \fBFDRESET\fP
+.TP
+.B FDRESET
resets the floppy controller under certain conditions.
-.IP \fBFDRAWCMD\fP
+.TP
+.B FDRAWCMD
sends a raw command to the floppy controller.
.PP
For more precise information, consult also the \fI<linux/fd.h>\fP and
The following
.BR ioctl (2)
calls are supported:
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPTIME, int \fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPTIME, int " arg )
Sets the amount of time that the driver sleeps before rechecking the printer
when the printer's buffer appears to be filled to
.IR arg .
This is in hundredths of a second, the default 2
being 0.02 seconds.
It influences only the polling driver.
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPCHAR, int \fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPCHAR, int " arg )
Sets the maximum number of busy-wait iterations which the polling driver does
while waiting for the printer to get ready for receiving a character to
.IR arg .
system gets too slow, decrease this number.
The default is 1000.
It influences only the polling driver.
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPABORT, int \fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPABORT, int " arg )
If
.I arg
is 0, the printer driver will retry on errors, otherwise
it will abort.
The default is 0.
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPABORTOPEN, int \fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPABORTOPEN, int " arg )
If
.I arg
is 0,
.BR open (2)
will be aborted on error, otherwise error will be ignored.
The default is to ignore it.
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPCAREFUL, int \fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPCAREFUL, int " arg )
If
.I arg
is 0, then the out-of-paper, offline, and error signals are
required to be false on all writes, otherwise they are ignored.
The default is to ignore them.
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPWAIT, int \fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPWAIT, int " arg )
Sets the number of busy waiting iterations to wait before strobing the
printer to accept a just-written character, and the number of iterations to
wait before turning the strobe off again,
For that reason, the default value is 0.
.\" FIXME . Actually, since Linux 2.2, the default is 1
This is used for both the polling and the interrupt driver.
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPSETIRQ, int \fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPSETIRQ, int " arg )
This
.BR ioctl (2)
requires superuser privileges.
When
.I arg
is 0, the polling driver will be used, which is also default.
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPGETIRQ, int *\fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPGETIRQ, int *" arg )
Stores the currently used IRQ in
.IR arg .
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPGETSTATUS, int *\fP\fIarg\fP\fB)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPGETSTATUS, int *" arg )
Stores the value of the status port in
.IR arg .
The bits have the following meaning:
.IP
Refer to your printer manual for the meaning of the signals.
Note that undocumented bits may also be set, depending on your printer.
-.IP "\fBint ioctl(int \fP\fIfd\fP\fB, LPRESET)\fP"
+.TP
+.BR "int ioctl(int " fd ", LPRESET)"
Resets the printer.
No argument is used.
.SH FILES
A value having zeros in the high-order 4 bits will be used to set the
drive's buffering mode.
The buffering modes are:
-.RS 12
-.IP 0 4
+.RS
+.TP
+.B 0
The drive will not report
.B GOOD
status on write commands until the data
blocks are actually written to the medium.
-.IP 1
+.TP
+.B 1
The drive may report
.B GOOD
status on write commands as soon as all the
data has been transferred to the drive's internal buffer.
-.IP 2
+.TP
+.B 2
The drive may report
.B GOOD
status on write commands as soon as (a) all
(3) \fIstate\fP \ %c
One of the following characters, indicating process state:
.RS
-.IP R 3
+.TP
+R
Running
-.IP S
+.TP
+S
Sleeping in an interruptible wait
-.IP D
+.TP
+D
Waiting in uninterruptible
disk sleep
-.IP Z
+.TP
+Z
Zombie
-.IP T
+.TP
+T
Stopped (on a signal) or (before Linux 2.6.33) trace stopped
-.IP t
+.TP
+t
.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29
Tracing stop (Linux 2.6.33 onward)
-.IP W
+.TP
+W
Paging (only before Linux 2.6.0)
-.IP X
+.TP
+X
Dead (from Linux 2.6.0 onward)
-.IP x
+.TP
+x
.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29
Dead (Linux 2.6.33 to
.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457
3.13 only)
-.IP K
+.TP
+K
.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29
Wakekill (Linux 2.6.33 to
.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457
3.13 only)
-.IP W
+.TP
+W
.\" commit 44d90df6b757c59651ddd55f1a84f28132b50d29
Waking (Linux 2.6.33 to
.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457
3.13 only)
-.IP P
+.TP
+P
.\" commit f2530dc71cf0822f90bb63ea4600caaef33a66bb
Parked (Linux 3.9 to
.\" commit 74e37200de8e9c4e09b70c21c3f13c2071e77457
3.13 only)
-.IP I
+.TP
+I
.\" commit 06eb61844d841d0032a9950ce7f8e783ee49c0d0
Idle (Linux 4.14 onward)
.RE
(on architectures that support ASLR).
Three values are supported for this file:
.RS
-.IP 0 3
+.TP
+.B 0
Turn ASLR off.
This is the default for architectures that don't support ASLR,
and when the kernel is booted with the
.I norandmaps
parameter.
-.IP 1
+.TP
+.B 1
Make the addresses of
.BR mmap (2)
allocations, the stack, and the VDSO page randomized.
at a randomized address.
This value is the default if the kernel was configured with
.BR CONFIG_COMPAT_BRK .
-.IP 2
+.TP
+.B 2
(Since Linux 2.6.25)
.\" commit c1d171a002942ea2d93b4fbd0c9583c56fce0772
Also support heap randomization.
This file contains 4 numbers defining limits for System V IPC semaphores.
These fields are, in order:
.RS
-.IP SEMMSL 8
+.TP
+SEMMSL
The maximum semaphores per semaphore set.
-.IP SEMMNS 8
+.TP
+SEMMNS
A system-wide limit on the number of semaphores in all semaphore sets.
-.IP SEMOPM 8
+.TP
+SEMOPM
The maximum number of operations that may be specified in a
.BR semop (2)
call.
-.IP SEMMNI 8
+.TP
+SEMMNI
A system-wide limit on the maximum number of semaphore identifiers.
.RE
.TP
.IP
The file has one of the following values:
.RS
-.IP 1: 4
+.TP
+.B 1
Kill all processes that have the corrupted-and-not-reloadable page mapped
as soon as the corruption is detected.
Note that this is not supported for a few types of pages,
such as kernel internally
allocated data or the swap cache, but works for the majority of user pages.
-.IP 0: 4
+.TP
+.B 0
Unmap the corrupted page from all processes and kill a process
only if it tries to access the page.
.RE
.\" The following is based on the text in Documentation/sysctl/vm.txt
Enable memory failure recovery (when supported by the platform).
.RS
-.IP 1: 4
+.TP
+.B 1
Attempt recovery.
-.IP 0: 4
+.TP
+.B 0
Always panic on a memory failure.
.RE
.IP
0 Null character.
A \exxx specifies the octal character xxx.
.RE
-.IP i
+.TP
+i
Increments parameters by one.
-.IP r
+.TP
+r
Single parameter capability
-.IP +
+.TP
++
Add value of next character to this parameter and do binary output
-.IP 2
+.TP
+2
Do ASCII output of this parameter with a field with of 2
-.IP d
+.TP
+d
Do ASCII output of this parameter with a field with of 3
-.IP %
+.TP
+%
Print a \(aq%\(aq
.PP
If you use binary output, then you should avoid the null character (\(aq\e0\(aq)
because it terminates the string.
You should reset tabulator expansion
if a tabulator can be the binary output of a parameter.
-.IP Warning:
+.TP
+Warning:
The above metacharacters for parameters may be wrong: they document Minix
termcap which may not be compatible with Linux termcap.
.PP
The block graphic characters can be specified by three string capabilities:
-.IP as
+.TP
+as
start the alternative charset
-.IP ae
+.TP
+ae
end the alternative charset
-.IP ac
+.TP
+ac
pairs of characters.
The first character is the name of the block graphic
symbol and the second characters is its definition.
.PP
where:
.RS 4
-.IP P() 6
+.TP
+P()
denotes the value of a thread capability set before the
.BR execve (2)
-.IP P'()
+.TP
+P'()
denotes the value of a thread capability set after the
.BR execve (2)
-.IP F()
+.TP
+F()
denotes a file capability set
.RE
.PP
have the following meanings.
.PP
.PD 0
-.IP \fB(1)\fR 4
+.TP
+.B 1
Perform immediate load balancing across Hyper-Thread
siblings on the same core.
-.IP \fB(2)\fR
+.TP
+.B 2
Perform immediate load balancing across other cores in the same package.
-.IP \fB(3)\fR
+.TP
+.B 3
Perform immediate load balancing across other CPUs
on the same node or blade.
-.IP \fB(4)\fR
+.TP
+.B 4
Perform immediate load balancing across over several
(implementation detail) nodes [On NUMA systems].
-.IP \fB(5)\fR
+.TP
+.B 5
Perform immediate load balancing across over all CPUs
in system [On NUMA systems].
.PD
where each directory contains a set of hard links to files.
.PP
Various operations (system calls) may be applied only to keyrings:
-.IP Adding
+.TP
+Adding
A key may be added to a keyring by system calls that create keys.
This prevents the new key from being immediately deleted
when the system call releases its last reference to the key.
-.IP Linking
+.TP
+Linking
A link may be added to a keyring pointing to a key that is already known,
provided this does not create a self-referential cycle.
-.IP Unlinking
+.TP
+Unlinking
A link may be removed from a keyring.
When the last link to a key is removed,
that key will be scheduled for deletion by the garbage collector.
-.IP Clearing
+.TP
+Clearing
All the links may be removed from a keyring.
-.IP Searching
+.TP
+Searching
A keyring may be considered the root of a tree or subtree in which keyrings
form the branches and non-keyrings the leaves.
This tree may be searched for a key matching
The first three sets are mutually exclusive.
One and only one will be in force for a particular access check.
In order of descending priority, these three sets are:
-.IP \fIuser\fR
+.TP
+.I user
The set specifies the rights granted
if the key's user ID matches the caller's filesystem user ID.
-.IP \fIgroup\fR
+.TP
+.I group
The set specifies the rights granted
if the user ID didn't match and the key's group ID matches the caller's
filesystem GID or one of the caller's supplementary group IDs.
-.IP \fIother\fR
+.TP
+.I other
The set specifies the rights granted
if neither the key's user ID nor group ID matched.
.PP
The fourth set of rights is:
-.IP \fIpossessor\fR
+.TP
+.I possessor
The set specifies the rights granted
if a key is determined to be possessed by the caller.
.PP
Flags (2)
A set of flags describing the state of the key:
.RS
-.IP I 4
+.TP
+I
.\" KEY_FLAG_INSTANTIATED
The key has been instantiated.
-.IP R
+.TP
+R
.\" KEY_FLAG_REVOKED
The key has been revoked.
-.IP D
+.TP
+D
.\" KEY_FLAG_DEAD
The key is dead (i.e., the key type has been unregistered).
.\" unregister_key_type() in the kernel source
(A key may be briefly in this state during garbage collection.)
-.IP Q
+.TP
+Q
.\" KEY_FLAG_IN_QUOTA
The key contributes to the user's quota.
-.IP U
+.TP
+U
.\" KEY_FLAG_USER_CONSTRUCT
The key is under construction via a callback to user space;
see
.BR request\-key (2).
-.IP N
+.TP
+N
.\" KEY_FLAG_NEGATIVE
The key is negatively instantiated.
-.IP i
+.TP
+i
.\" KEY_FLAG_INVALIDATED
The key has been invalidated.
.RE
The
.B man
package has the following predefined strings:
-.IP \e*R
+.TP
+\e*R
Registration Symbol: \*R
-.IP \e*S
+.TP
+\e*S
Change to default font size
-.IP \e*(Tm
+.TP
+\e*(Tm
Trademark Symbol: \*(Tm
-.IP \e*(lq
+.TP
+\e*(lq
Left angled double quote: \*(lq
-.IP \e*(rq
+.TP
+\e*(rq
Right angled double quote: \*(rq
.SS Safe subset
Although technically
.in
.PP
The fields of this structure are as follows:
-.IP * 3
+.TP
.I sll_protocol
is the standard ethernet protocol type in network byte order as defined
in the
.I <linux/if_ether.h>
include file.
It defaults to the socket's protocol.
-.IP *
+.TP
.I sll_ifindex
is the interface index of the interface
(see
is an ARP type as defined in the
.I <linux/if_arp.h>
include file.
-.IP *
+.TP
.I sll_pkttype
contains the packet type.
Valid types are
for a packet originating from the local host that is looped back to a packet
socket.
These types make sense only for receiving.
-.IP *
+.TP
.I sll_addr
-and
+.TQ
.I sll_halen
contain the physical-layer (e.g., IEEE 802.3) address and its length.
The exact interpretation depends on the device.
.I <sys/queue.h>
header file provides a set of macros that
define and operate on the following data structures:
-.IP * 3
-singly linked lists (SLIST)
-.IP *
-doubly linked lists (LIST)
-.IP *
-singly linked tail queues (STAILQ)
-.IP *
-doubly linked tail queues (TAILQ)
-.IP *
-doubly linked circular queues (CIRCLEQ)
+.TP
+SLIST
+singly linked lists
+.TP
+LIST
+doubly linked lists
+.TP
+STAILQ
+singly linked tail queues
+.TP
+TAILQ
+doubly linked tail queues
+.TP
+CIRCLEQ
+doubly linked circular queues
.PP
All structures support the following functionality:
.IP * 3
.PP
The entries in the "Action" column of the table below specify
the default disposition for each signal, as follows:
-.IP Term
+.TP
+Term
Default action is to terminate the process.
-.IP Ign
+.TP
+Ign
Default action is to ignore the signal.
-.IP Core
+.TP
+Core
Default action is to terminate the process and dump core (see
.BR core (5)).
-.IP Stop
+.TP
+Stop
Default action is to stop the process.
-.IP Cont
+.TP
+Cont
Default action is to continue the process if it is currently stopped.
.PP
A process can change the disposition of a signal using
more slowly in response to partial acknowledgements.
Possible values are:
.RS
-.IP 0 3
+.TP
+.B 0
increase
.I cwnd
once per acknowledgement (no ABC)
-.IP 1
+.TP
+.B 1
increase
.I cwnd
once per acknowledgement of full sized segment
-.IP 2
+.TP
+.B 2
allow increase
.I cwnd
by two if acknowledgement is
.IP
This file can have one of the following values:
.RS
-.IP 0
+.TP
+.B 0
Disable ECN.
Neither initiate nor accept ECN.
This was the default up to and including Linux 2.6.30.
-.IP 1
+.TP
+.B 1
Enable ECN when requested by incoming connections and also
request ECN on outgoing connection attempts.
-.IP 2
+.TP
+.B 2
.\" commit 255cac91c3c9ce7dca7713b93ab03c75b7902e0e
Enable ECN when requested by incoming connections,
but do not request ECN on outgoing connections.
.IP
This file can have one of the following values:
.RS
-.IP 0 3
+.TP
+.B 0
Disabled.
This was the default up to and including Linux 2.6.23.
-.IP 1
+.TP
+.B 1
The basic version F-RTO algorithm is enabled.
-.IP 2
+.TP
+.B 2
.\" commit c96fd3d461fa495400df24be3b3b66f0e0b152f9
Enable SACK-enhanced F-RTO if flow uses SACK.
The basic version can be used also when
TCP has several options concerning what to do next.
Possible values are:
.RS
-.IP 0 3
+.TP
+.B 0
Rate halving based; a smooth and conservative response,
results in halved congestion window
.RI ( cwnd )
and slow-start threshold
.RI ( ssthresh )
after one RTT.
-.IP 1
+.TP
+.B 1
Very conservative response; not recommended because even
though being valid, it interacts poorly with the rest of Linux TCP; halves
.I cwnd
and
.I ssthresh
immediately.
-.IP 2
+.TP
+.B 2
Aggressive response; undoes congestion-control measures
that are now known to be unnecessary
(ignoring the possibility of a lost retransmission that would require
This parameter controls TCP Packetization-Layer Path MTU Discovery.
The following values may be assigned to the file:
.RS
-.IP 0 3
+.TP
+.B 0
Disabled
-.IP 1
+.TP
+.B 1
Disabled by default, enabled when an ICMP black hole detected
-.IP 2
+.TP
+.B 2
Always enabled, use initial MSS of
.IR tcp_base_mss .
.RE
.IR tcp_abort_on_overflow .
Set to one of the following values:
.RS
-.IP 0 3
+.TP
+.B 0
Disable TCP syncookies.
-.IP 1
+.TP
+.B 1
Send out syncookies when the syn backlog queue of a socket overflows.
-.IP 2
+.TP
+.B 2
(since Linux 3.12)
.\" commit 5ad37d5deee1ff7150a2d0602370101de158ad86
Send out syncookies unconditionally.
Set to one of the following values to enable or disable RFC\ 1323
TCP timestamps:
.RS
-.IP 0 3
+.TP
+.B 0
Disable timestamps.
-.IP 1
+.TP
+.B 1
Enable timestamps as defined in RFC1323 and use random offset for
each connection rather than only using the current time.
-.IP 2
+.TP
+.B 2
As for the value 1, but without random offsets.
.\" commit 25429d7b7dca01dc4f17205de023a30ca09390d0
Setting
Three types of address are distinguished in the
.I sockaddr_un
structure:
-.IP * 3
-.IR pathname :
+.TP
+pathname
a UNIX domain socket can be bound to a null-terminated
filesystem pathname using
.BR bind (2).
expression more portably describes the size of the address structure.)
.IP
For further details of pathname sockets, see below.
-.IP *
-.IR unnamed :
+.TP
+unnamed
A stream socket that has not been bound to a pathname using
.BR bind (2)
has no name.
should not be inspected.
.\" There is quite some variation across implementations: FreeBSD
.\" says the length is 16 bytes, HP-UX 11 says it's zero bytes.
-.IP *
-.IR abstract :
+.TP
+abstract
an abstract socket address is distinguished (from a pathname socket)
by the fact that
.I sun_path[0]
.UE
for more information on the LDAP URL scheme.
The components of this URL are:
-.IP hostport 12
+.TP
+hostport
the LDAP server to query, written as a hostname optionally followed by
a colon and the port number.
The default LDAP port is TCP port 389.
If empty, the client determines which the LDAP server to use.
-.IP dn
+.TP
+dn
the LDAP Distinguished Name, which identifies
the base object of the LDAP search (see
.UR http://www.ietf.org\:/rfc\:/rfc2253.txt
RFC\ 2253
.UE
section 3).
-.IP attributes
+.TP
+attributes
a comma-separated list of attributes to be returned;
see RFC\ 2251 section 4.1.5.
If omitted, all attributes should be returned.
-.IP scope
+.TP
+scope
specifies the scope of the search, which can be one of
"base" (for a base object search), "one" (for a one-level search),
or "sub" (for a subtree search).
If scope is omitted, "base" is assumed.
-.IP filter
+.TP
+filter
specifies the search filter (subset of entries
to return).
If omitted, all entries should be returned.
RFC\ 2254
.UE
section 4.
-.IP extensions
+.TP
+extensions
a comma-separated list of type=value
pairs, where the =value portion may be omitted for options not
requiring it.
projects / thirdparty / man-pages.git / commitdiff
