mirrors/pv
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Use copy_file_range() for transfers if it is available (#196).

Browse Source
This commit is contained in:
Andrew Wood
2026-05-31 22:18:18 +01:00
parent 85918358a5
commit 6130d65249
9 changed files with 557 additions and 185 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docs/pv.1
+24 -14
View File
@@ -290,23 +290,26 @@ better with specific buffer sizes such as 1024.
Implies \*(lq\fB\-\-no\-splice\fR\*(rq.
.TP
.B \-C, \-\-no-splice
Prevent the use of \fBsplice\fR(2), a system call normally used on systems
that support it to improve efficiency by eliminating the need for a transfer
buffer.
Prevent the use of \fBsplice\fR(2) and \fBcopy_file_range\fR(2), which are
normally used on systems that support it to improve efficiency by
eliminating the need for a transfer buffer.
.IP
In the default case that \fBsplice\fR(2) is used, the lack of a transfer
buffer prevents \*(lq\fB\-\-buffer\-percent\fR\*(rq and
In the default case that \fBsplice\fR(2) or \fBcopy_file_range\fR(2) are
used, the lack of a transfer buffer prevents
\*(lq\fB\-\-buffer\-percent\fR\*(rq and
\*(lq\fB\-\-last\-written\fR\*(rq from working and makes
\*(lq\fB\-\-buffer\-size\fR\*(rq redundant, so using any of those options
automatically switches on \*(lq\fB\-\-no\-splice\fR\*(rq.
.IP
Sparse files cannot be written with \fBsplice\fR(2), so using
Sparse files cannot be written with \fBsplice\fR(2) or
\fBcopy_file_range\fR(2), so using
\*(lq\fB\-\-sparse\fR\*(rq automatically switches on
\*(lq\fB\-\-no\-splice\fR\*(rq.
.IP
Switching on \*(lq\fB\-\-no\-splice\fR\*(rq results in a small loss of
transfer efficiency.
It has no effect on systems where \fBsplice\fR(2) is unavailable.
It has no effect on systems where \fBsplice\fR(2) and
\fBcopy_file_range\fR(2) are unavailable.
.TP
.BI \-J\ BYTES \fR,\ \fB\-\-pipe\-buffer\-size\ BYTES
Attempt to set the size of the output pipe buffer, and the intermediate
@@ -349,7 +352,7 @@ end of input.
.TP
.B \-Y, \-\-sync
After every write operation, synchronise the buffer caches to disk with
\fBfdatasync\fR(2).
\fBsync\fR(2), or \fBfdatasync\fR(2) if possible.
This has no effect when the output is a pipe.
Using \*(lq\fB\-\-sync\fR\*(rq may improve the accuracy of the progress bar
when writing to a slow disk.
@@ -562,21 +565,26 @@ transferred by this side, in \*(lq\fB\-\-monitor\~both\fR\*(rq mode.
.TP
.BR %T ", " %{buffer\-percent}
Percentage of the transfer buffer in use.
Equivalent to \*(lq\fB\-\-buffer\-percent\fR\*(rq.
Displays \*(lq{\-\-\-\-}\*(rq if the transfer is being done with
\fBsplice\fR(2), since splicing to or from pipes does not use the buffer.
Equivalent to \*(lq\fB\-\-buffer\-percent\fR\*(rq, but using it does not
turn on \*(lq\fB\-\-no\-splice\fR\*(rq.
.IP
If the transfer is using \fBsplice\fR(2), displays \*(lq{\-\-\-\-}\*(rq; if
the transfer is using \fBsplice\fR(2) via an intermediate input pipe,
displays \*(lq{\-||\-}\*(rq; and if the transfer is using
\fBcopy_file_range\fR(2), displays \*(lq{\-\-\->}\*(rq.
.TP
.BR %nA ", " %n{last\-written}
Show the last \fIn\fR bytes written (for example, \*(lq\fB%16A\fR\*(rq shows
the last 16 bytes).
Shows only dots if the transfer is being done with \fBsplice\fR(2), since
splicing to or from pipes does not use the buffer.
Shows only dots if the transfer is using \fBsplice\fR(2) or
\fBcopy_file_range\fR(2), since these transfer modes do not use the buffer.
.TP
.BR %nL ", " %n{previous\-line}
Show the first \fIn\fR bytes of the most recently written line (for example,
\*(lq\fB%40L\fR\*(rq shows the first 40 bytes).
If no \fIn\fR is given, then this expands to fill the available space.
Shows only spaces if the transfer is being done with \fBsplice\fR(2).
Shows only spaces if the transfer is using \fBsplice\fR(2) or
\fBcopy_file_range\fR(2).
.TP
.BR %N ", " %{name}
Show the name prefix given by \*(lq\fB\-\-name\fR\*(rq.
@@ -912,6 +920,8 @@ Please report bugs or feature requests via the issue tracker linked from the
.SH "SEE ALSO"
.BR cat (1),
.BR splice (2),
.BR copy_file_range (2),
.BR fsync (2),
.BR fdatasync (2),
.BR open (2)
(for \fBO_DIRECT\fR),
docs/pv.1.md
+29 -24
View File
@@ -297,22 +297,23 @@ are explicitly switched on will be shown.
**-C, \--no-splice**
: Prevent the use of **splice**(2), a system call normally used on
systems that support it to improve efficiency by eliminating the
need for a transfer buffer.
: Prevent the use of **splice**(2) and **copy_file_range**(2), which
are normally used on systems that support it to improve efficiency
by eliminating the need for a transfer buffer.
In the default case that **splice**(2) is used, the lack of a
transfer buffer prevents "**\--buffer-percent**" and
"**\--last-written**" from working and makes "**\--buffer-size**"
redundant, so using any of those options automatically switches on
"**\--no-splice**".
In the default case that **splice**(2) or **copy_file_range**(2) are
used, the lack of a transfer buffer prevents "**\--buffer-percent**"
and "**\--last-written**" from working and makes
"**\--buffer-size**" redundant, so using any of those options
automatically switches on "**\--no-splice**".
Sparse files cannot be written with **splice**(2), so using
"**\--sparse**" automatically switches on "**\--no-splice**".
Sparse files cannot be written with **splice**(2) or
**copy_file_range**(2), so using "**\--sparse**" automatically
switches on "**\--no-splice**".
Switching on "**\--no-splice**" results in a small loss of transfer
efficiency. It has no effect on systems where **splice**(2) is
unavailable.
efficiency. It has no effect on systems where **splice**(2) and
**copy_file_range**(2) are unavailable.
**-J BYTES, \--pipe-buffer-size BYTES**
@@ -360,9 +361,9 @@ are explicitly switched on will be shown.
**-Y, \--sync**
: After every write operation, synchronise the buffer caches to disk
with **fdatasync**(2). This has no effect when the output is a pipe.
Using "**\--sync**" may improve the accuracy of the progress bar
when writing to a slow disk.
with **sync**(2), or **fdatasync**(2) if possible. This has no
effect when the output is a pipe. Using "**\--sync**" may improve
the accuracy of the progress bar when writing to a slow disk.
**-K, \--direct-io**
@@ -585,23 +586,27 @@ contain the following sequences:
**%T**, **%{buffer-percent}**
: Percentage of the transfer buffer in use. Equivalent to
"**\--buffer-percent**". Displays "{\-\-\--}" if the transfer is
being done with **splice**(2), since splicing to or from pipes does
not use the buffer.
"**\--buffer-percent**", but using it does not turn on
"**\--no-splice**".
If the transfer is using **splice**(2), displays "{\-\-\--}"; if the
transfer is using **splice**(2) via an intermediate input pipe,
displays "{-\|\|-}"; and if the transfer is using
**copy_file_range**(2), displays "{\-\--\>}".
**%nA**, **%n{last-written}**
: Show the last *n* bytes written (for example, "**%16A**" shows the
last 16 bytes). Shows only dots if the transfer is being done with
**splice**(2), since splicing to or from pipes does not use the
buffer.
last 16 bytes). Shows only dots if the transfer is using
**splice**(2) or **copy_file_range**(2), since these transfer modes
do not use the buffer.
**%nL**, **%n{previous-line}**
: Show the first *n* bytes of the most recently written line (for
example, "**%40L**" shows the first 40 bytes). If no *n* is given,
then this expands to fill the available space. Shows only spaces if
the transfer is being done with **splice**(2).
the transfer is using **splice**(2) or **copy_file_range**(2).
**%N**, **%{name}**
@@ -862,8 +867,8 @@ the [**pv** home page](https://ivarch.com/p/pv).
# SEE ALSO
**cat**(1), **splice**(2), **fdatasync**(2), **open**(2) (for
**O_DIRECT**), **console_codes**(4)
**cat**(1), **splice**(2), **copy_file_range**(2), **fsync**(2),
**fdatasync**(2), **open**(2) (for **O_DIRECT**), **console_codes**(4)
# COPYRIGHT