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* [PATCH] man2/splice.2: document SPLICE_F_NOWAIT
@ 2023-09-26  7:04 Max Kellermann
  2023-09-26 12:01 ` Alejandro Colomar
  0 siblings, 1 reply; 4+ messages in thread
From: Max Kellermann @ 2023-09-26  7:04 UTC (permalink / raw)
  To: alx, linux-man, brauner, axboe
  Cc: linux-kernel, linux-api, libc-alpha, Max Kellermann

Patch for SPLICE_F_NOWAIT submitted to LKML:
 https://lore.kernel.org/lkml/20230926063609.2451260-1-max.kellermann@ionos.com/

In the HISTORY section, I declared Linux 6.7 as the first version to
have this feature, but this is only speculation, because
SPLICE_F_NOWAIT is still under discussion and has not yet been merged.

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
---
 man2/splice.2 | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/man2/splice.2 b/man2/splice.2
index e9a18e668..1e686b858 100644
--- a/man2/splice.2
+++ b/man2/splice.2
@@ -89,13 +89,27 @@ call);
 in the future, a correct implementation may be restored.
 .TP
 .B SPLICE_F_NONBLOCK
-Do not block on I/O.
+Do not block on I/O on pipes.
 This makes the splice pipe operations nonblocking, but
 .BR splice ()
 may nevertheless block because the file descriptors that
 are spliced to/from may block (unless they have the
 .B O_NONBLOCK
-flag set).
+flag set or
+.B SPLICE_F_NOWAIT
+is specified).
+.TP
+.B SPLICE_F_NOWAIT
+If no data is immediately available on
+.I fd_in
+and it is not a pipe, do not wait (e.g. for backing storage or locks),
+but return immediately with
+.B EAGAIN.
+This is analogous to the
+.B RWF_NOWAIT
+flag of
+.BR preadv2()
+.
 .TP
 .B SPLICE_F_MORE
 More data will be coming in a subsequent splice.
@@ -138,6 +152,8 @@ is set to indicate the error.
 .TP
 .B EAGAIN
 .B SPLICE_F_NONBLOCK
+or
+.B SPLICE_F_NOWAIT
 was specified in
 .I flags
 or one of the file descriptors had been marked as nonblocking
@@ -192,6 +208,9 @@ was required to be a pipe.
 Since Linux 2.6.31,
 .\" commit 7c77f0b3f9208c339a4b40737bb2cb0f0319bb8d
 both arguments may refer to pipes.
+.PP
+.B SPLICE_F_NOWAIT
+was added in Linux 6.7.
 .SH NOTES
 The three system calls
 .BR splice (),
-- 
2.39.2


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2023-09-27 11:29 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-09-26  7:04 [PATCH] man2/splice.2: document SPLICE_F_NOWAIT Max Kellermann
2023-09-26 12:01 ` Alejandro Colomar
2023-09-26 13:43   ` [PATCH v2] " Max Kellermann
2023-09-27 11:29     ` Alejandro Colomar

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