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165:. A pipe buffer is an in-kernel memory buffer that is opaque to the userspace process. A user process can splice the contents of a source file into this pipe buffer, then splice the pipe buffer into the destination file, all without moving any data through userspace.
873:
with sockets, the network controller (NIC) should support DMA, otherwise splice() will not deliver a large performance improvement. The reason for this is that each page of the pipe will just fill up to frame size (1460 bytes of the available 4096 bytes per page).
157:, one can move data from one file descriptor to another without incurring any copies from user space into kernel space, which is usually required to enforce system security and also to keep a simple interface for processes to read and write to files.
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performance. As linear addresses do not necessarily correspond to contiguous physical addresses, this may not be possible in all cases and on all hardware combinations.
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moves or copies data between a pipe and user space. Ideally, splice and vmsplice work by remapping pages and do not actually copy any data, which may improve
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is the last part of the trilogy. It duplicates one pipe to another, enabling forks in the way applications are connected with pipes.
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can map an application data area into a pipe (or vice versa), thus allowing transfers between pipes and user memory where
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and a pipe without a round trip to user space. The related system call
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splice implementation borrows some ideas from an original proposal by
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616:/* splice the data in the pipe (in kernel memory) into the file. */
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478:/* splice the file into the pipe (data in kernel memory). */
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Two new system calls: splice() and sync_file_range()
195:in 1998. The splice system calls first appeared in
46:. Unsourced material may be challenged and removed.
857:transfers between a file descriptor and a pipe.
292:/* Splice flags (not laid down in stone yet). */
845:is one of three system calls that complete the
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8:
933:. kerneltrap.org. 2006-04-21. Archived from
199:kernel version 2.6.17 and were written by
287:Some constants that are of interest are:
180:in a 2006 email, which was included in a
106:Learn how and when to remove this message
338:This is an example of splice in action:
919:
979:: CS1 maint: archived copy as title (
972:
931:"Linux: Explaining splice() and tee()"
7:
925:
923:
325:#define SPLICE_F_GIFT 0x08
316:#define SPLICE_F_MORE 0x04
307:#define SPLICE_F_NONBLOCK 0x02
298:#define SPLICE_F_MOVE 0x01
44:adding citations to reliable sources
343:/* Transfer from disk to a log. */
14:
881:Not all filesystem types support
20:
31:needs additional citations for
878:does not support UDP sockets.
1:
1051:
838:Complementary system calls
131:that moves data between a
304:#ifndef SPLICE_F_NONBLOCK
55:"Splice" system call
340:
289:
210:
889:sockets do not support
1030:Linux kernel features
1014:Some new system calls
322:#ifndef SPLICE_F_GIFT
313:#ifndef SPLICE_F_MORE
295:#ifndef SPLICE_F_MOVE
40:improve this article
1000:(kernelnewbies.org)
998:Linux kernel 2.6.17
161:works by using the
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133:file descriptor
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992:External links
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849:architecture.
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174:Linus Torvalds
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962:on 2016-03-04
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937:on 2013-05-21
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706:SPLICE_F_MOVE
700:SPLICE_F_MORE
553:SPLICE_F_MOVE
547:SPLICE_F_MORE
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57: –
56:
52:
51:Find sources:
45:
41:
35:
34:
29:This article
27:
23:
18:
17:
1035:System calls
964:. Retrieved
960:the original
950:
939:. Retrieved
935:the original
880:
868:
865:Requirements
855:sys_splice()
841:
337:
286:
186:
172:
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118:
117:
102:
93:
83:
76:
69:
62:
50:
38:Please help
33:verification
30:
903:System call
869:When using
193:Larry McVoy
163:pipe buffer
129:system call
1024:Categories
966:2016-02-28
941:2014-04-27
914:References
851:vmsplice()
358:log_handle
349:log_blocks
201:Jens Axboe
182:KernelTrap
176:described
138:vmsplice()
127:-specific
96:March 2011
66:newspapers
1016:(LWN.net)
908:Zero-copy
885:. Also,
688:fd_offset
207:Prototype
184:article.
975:cite web
897:See also
891:splice()
883:splice()
876:splice()
871:splice()
847:splice()
843:splice()
742:to_write
694:to_write
625:to_write
604:to_write
589:to_write
541:to_write
487:to_write
421:to_write
273:unsigned
178:splice()
159:splice()
155:splice()
149:Workings
120:splice()
1008:LWN.net
887:AF_UNIX
781:filedes
769:filedes
652:filedes
529:filedes
445:filedes
403:filedes
334:Example
258:off_out
213:ssize_t
169:Origins
80:scholar
823:return
811:return
682:handle
664:handle
646:splice
523:offset
508:splice
418:size_t
388:size_t
382:offset
379:loff_t
364:handle
355:struct
328:#endif
319:#endif
310:#endif
301:#endif
264:size_t
252:loff_t
246:fd_out
237:off_in
231:loff_t
216:splice
82:
75:
68:
61:
53:
859:tee()
817:errno
775:close
763:close
685:->
676:&
667:->
619:while
520:&
481:while
279:flags
225:fd_in
197:Linux
189:Linux
153:With
125:Linux
123:is a
87:JSTOR
73:books
981:link
802:<
757:pipe
739:else
733:pipe
730:goto
721:<
658:NULL
628:>
610:size
586:else
580:pipe
577:goto
568:<
535:NULL
490:>
469:goto
460:<
439:pipe
427:size
391:size
187:The
59:news
799:ret
787:out
748:ret
718:ret
640:ret
595:ret
565:ret
502:ret
472:out
457:ret
433:ret
412:ret
409:int
400:int
370:int
346:int
276:int
267:len
243:int
222:int
143:I/O
42:by
1026::
977:}}
973:{{
922:^
893:.
793:if
784:);
772:);
745:-=
712:if
709:);
691:),
670:fd
592:-=
559:if
556:);
514:fd
451:if
448:);
373:fd
282:);
203:.
1010:)
1006:(
983:)
969:.
944:.
832:}
829:;
826:0
820:;
814:-
808:)
805:0
796:(
790::
778:(
766:(
760::
754:}
751:;
736:;
727:)
724:0
715:(
703:|
697:,
679:(
673:,
661:,
655:,
649:(
643:=
637:{
634:)
631:0
622:(
613:;
607:=
601:}
598:;
583:;
574:)
571:0
562:(
550:|
544:,
538:,
532:,
526:,
517:,
511:(
505:=
499:{
496:)
493:0
484:(
475:;
466:)
463:0
454:(
442:(
436:=
430:;
424:=
415:;
406:;
397:{
394:)
385:,
376:,
367:,
361:*
352:(
270:,
261:,
255:*
249:,
240:,
234:*
228:,
219:(
109:)
103:(
98:)
94:(
84:·
77:·
70:·
63:·
36:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
