Io uring and xdp enter 2024 - revision history

Dank: /* io_uring */

2024-03-09T07:24:12Z

io_uring

← Older revision		Revision as of 07:24, 9 March 2024
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	Also new is <tt>IORING_OP_WAITID</tt> for working with process state changes (though I would recommend use of [[pidfd\|pidfds]] for this kind of thing in new code).		Also new is <tt>IORING_OP_WAITID</tt> for working with process state changes (though I would recommend use of [[pidfd\|pidfds]] for this kind of thing in new code).

	[https://git.kernel.dk/cgit/linux/commit/?h=io_uring-send-queue&id=060845d3788f20b427631b64a6dbdbd249a0309b Kernel 6.8] introduces <tt>IORING_SEND_MULTISHOT</tt>, bringing the multishot pattern to the TX (<tt>send</tt> and <tt>sendmsg</tt>) side.		[https://git.kernel.dk/cgit/linux/commit/?h=io_uring-send-queue&id=060845d3788f20b427631b64a6dbdbd249a0309b Kernel 6.8] introduces <tt>IORING_SEND_MULTISHOT</tt>, bringing the multishot pattern to the TX (<tt>send</tt> and <tt>sendmsg</tt>) side. See Axboe's "[https://lore.kernel.org/io-uring/20240308235045.1014125-1-axboe@kernel.dk/ Send and receive bundles]" post for further optimization using "bundles" (these require registered buffers).

	<tt>IORING_SETUP_REGISTERED_FD_ONLY</tt> registers the ring fd for use with <tt>IORING_REGISTER_USE_REGISTERED_RING</tt>.		<tt>IORING_SETUP_REGISTERED_FD_ONLY</tt> registers the ring fd for use with <tt>IORING_REGISTER_USE_REGISTERED_RING</tt>.

Dank at 18:47, 20 February 2024

2024-02-20T18:47:28Z

← Older revision		Revision as of 18:47, 20 February 2024
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	'''[[Dankblog\|dankblog!]] 2024-02-15, 1452 EST, at [[Viewpoint\|the danktower]]'''		'''[[Dankblog\|dankblog!]] 2024-02-15, 1452 EST, at [[Viewpoint\|the danktower]]'''

	Last year (2023), I spent significant time writing code using [[XDP]] and [[io_uring]]. The latter was delightful, the former less so~~. My summary of io_uring through liburing 2.3 hit #1 on HackerNews (twice!) and the great [https://lwn.net/Articles/932568/ LWN], which pleased me--it's nice to know people are reading this~~. Work on these technologies has progressed, and it seems time for an update.		Last year (2023), I spent significant time writing code using [[XDP]] and [[io_uring]]. The latter was delightful, the former less so. Work on these technologies has progressed, and it seems time for an update.

	==XDP==		==XDP==

Dank: /* io_uring */

2024-02-20T18:30:17Z

io_uring

← Older revision		Revision as of 18:30, 20 February 2024
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	I used to have the following on my io_uring page:		I used to have the following on my io_uring page:

	It would be nice to have tight integration with condition variables or even mutex/futex (allow me to submit a request to get a lock, and when i get the CQE, i have that lock). Bonus points if the fast (uncontended) path never needs a system call (like mutexes built atop futexes today).		<q>It would be nice to have tight integration with condition variables or even mutex/futex (allow me to submit a request to get a lock, and when i get the CQE, i have that lock). Bonus points if the fast (uncontended) path never needs a system call (like mutexes built atop futexes today).</q>

	The new API appears to satisfy all my desires!		The new API appears to satisfy all my desires!

Dank: /* io_uring */

2024-02-20T17:31:35Z

io_uring

← Older revision		Revision as of 17:31, 20 February 2024
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	<tt>io_uring_prep_cmd_sock(2)</tt> configures <tt>IORING_OP_URING_CMD</tt> SQEs to perform <tt>setsockopt(2)</tt> operations.		<tt>io_uring_prep_cmd_sock(2)</tt> configures <tt>IORING_OP_URING_CMD</tt> SQEs to perform <tt>setsockopt(2)</tt> operations.

	<tt>io_uring_prep_getxattr(2)</tt> and <tt>io_uring_prep_setxattr(2) prep SQEs for <tt>getxattr(2)</tt> and <tt>setxattr(2)</tt> operations; <tt>io_uring_prep_fgetxattr(2)</tt> and <tt>io_uring_prep_fsetxattr(2)</tt> do exactly what you'd think.		<tt>io_uring_prep_getxattr(2)</tt> and <tt>io_uring_prep_setxattr(2)</tt> prep SQEs for <tt>getxattr(2)</tt> and <tt>setxattr(2)</tt> operations; <tt>io_uring_prep_fgetxattr(2)</tt> and <tt>io_uring_prep_fsetxattr(2)</tt> do exactly what you'd think.

	Making huge pages as unpleasant as possible to use is a central tenet (perhaps <i>the</i> central tenet) underpinning the entire Linux mission, but <tt>IORING_SETUP_NO_MMAP</tt> was [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=03d89a2de25b added in 6.5], huzzah!		Making huge pages as unpleasant as possible to use is a central tenet (perhaps <i>the</i> central tenet) underpinning the entire Linux mission, but <tt>IORING_SETUP_NO_MMAP</tt> was [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=03d89a2de25b added in 6.5], huzzah!

Dank: /* io_uring */

2024-02-20T16:17:13Z

io_uring

← Older revision		Revision as of 16:17, 20 February 2024
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	Also new is <tt>IORING_OP_WAITID</tt> for working with process state changes (though I would recommend use of [[pidfd\|pidfds]] for this kind of thing in new code).		Also new is <tt>IORING_OP_WAITID</tt> for working with process state changes (though I would recommend use of [[pidfd\|pidfds]] for this kind of thing in new code).

	Kernel 6.8 introduces <tt>IORING_SEND_MULTISHOT</tt>, bringing the multishot pattern to the TX side.		[https://git.kernel.dk/cgit/linux/commit/?h=io_uring-send-queue&id=060845d3788f20b427631b64a6dbdbd249a0309b Kernel 6.8] introduces <tt>IORING_SEND_MULTISHOT</tt>, bringing the multishot pattern to the TX (<tt>send</tt> and <tt>sendmsg</tt>) side.

	<tt>IORING_SETUP_REGISTERED_FD_ONLY</tt> registers the ring fd for use with <tt>IORING_REGISTER_USE_REGISTERED_RING</tt>.		<tt>IORING_SETUP_REGISTERED_FD_ONLY</tt> registers the ring fd for use with <tt>IORING_REGISTER_USE_REGISTERED_RING</tt>.

Dank: /* io_uring */

2024-02-20T16:16:09Z

io_uring

← Older revision		Revision as of 16:16, 20 February 2024
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	Also new is <tt>IORING_OP_WAITID</tt> for working with process state changes (though I would recommend use of [[pidfd\|pidfds]] for this kind of thing in new code).		Also new is <tt>IORING_OP_WAITID</tt> for working with process state changes (though I would recommend use of [[pidfd\|pidfds]] for this kind of thing in new code).

			Kernel 6.8 introduces <tt>IORING_SEND_MULTISHOT</tt>, bringing the multishot pattern to the TX side.

	<tt>IORING_SETUP_REGISTERED_FD_ONLY</tt> registers the ring fd for use with <tt>IORING_REGISTER_USE_REGISTERED_RING</tt>.		<tt>IORING_SETUP_REGISTERED_FD_ONLY</tt> registers the ring fd for use with <tt>IORING_REGISTER_USE_REGISTERED_RING</tt>.

Dank at 19:53, 15 February 2024

2024-02-15T19:53:38Z

@@ Line 1: / Line 1: @@
 Last year (2023), I spent significant time writing code using [[XDP]] and [[io_uring]]. The latter was delightful, the former less so. My summary of io_uring through liburing 2.3 hit #1 on HackerNews (twice!) and the great [https://lwn.net/Articles/932568/ LWN], which pleased me--it's nice to know people are reading this. Work on these technologies has progressed, and it seems time for an update.
@@ Line 25: / Line 27: @@
 ==See also==
 * [https://elixir.bootlin.com/linux/latest/source/Documentation/networking/af_xdp.rst AF_XDP] kernel documentation

Dank: /* io_uring */

2024-02-15T15:57:17Z

io_uring

← Older revision		Revision as of 15:57, 15 February 2024
Line 20:		Line 20:

	<tt>io_uring_prep_getxattr(2)</tt> and <tt>io_uring_prep_setxattr(2) prep SQEs for <tt>getxattr(2)</tt> and <tt>setxattr(2)</tt> operations; <tt>io_uring_prep_fgetxattr(2)</tt> and <tt>io_uring_prep_fsetxattr(2)</tt> do exactly what you'd think.		<tt>io_uring_prep_getxattr(2)</tt> and <tt>io_uring_prep_setxattr(2) prep SQEs for <tt>getxattr(2)</tt> and <tt>setxattr(2)</tt> operations; <tt>io_uring_prep_fgetxattr(2)</tt> and <tt>io_uring_prep_fsetxattr(2)</tt> do exactly what you'd think.

			Making huge pages as unpleasant as possible to use is a central tenet (perhaps <i>the</i> central tenet) underpinning the entire Linux mission, but <tt>IORING_SETUP_NO_MMAP</tt> was [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=03d89a2de25b added in 6.5], huzzah!

	==See also==		==See also==
	* [https://elixir.bootlin.com/linux/latest/source/Documentation/networking/af_xdp.rst AF_XDP] kernel documentation		* [https://elixir.bootlin.com/linux/latest/source/Documentation/networking/af_xdp.rst AF_XDP] kernel documentation

Dank: /* io_uring */

2024-02-15T14:59:22Z

io_uring

← Older revision		Revision as of 14:59, 15 February 2024
Line 18:		Line 18:

	<tt>io_uring_prep_cmd_sock(2)</tt> configures <tt>IORING_OP_URING_CMD</tt> SQEs to perform <tt>setsockopt(2)</tt> operations.		<tt>io_uring_prep_cmd_sock(2)</tt> configures <tt>IORING_OP_URING_CMD</tt> SQEs to perform <tt>setsockopt(2)</tt> operations.

			<tt>io_uring_prep_getxattr(2)</tt> and <tt>io_uring_prep_setxattr(2) prep SQEs for <tt>getxattr(2)</tt> and <tt>setxattr(2)</tt> operations; <tt>io_uring_prep_fgetxattr(2)</tt> and <tt>io_uring_prep_fsetxattr(2)</tt> do exactly what you'd think.

	==See also==		==See also==
	* [https://elixir.bootlin.com/linux/latest/source/Documentation/networking/af_xdp.rst AF_XDP] kernel documentation		* [https://elixir.bootlin.com/linux/latest/source/Documentation/networking/af_xdp.rst AF_XDP] kernel documentation

Dank: /* io_uring */

2024-02-15T14:53:23Z

io_uring

← Older revision		Revision as of 14:53, 15 February 2024
Line 16:		Line 16:

	<tt>IORING_SETUP_REGISTERED_FD_ONLY</tt> registers the ring fd for use with <tt>IORING_REGISTER_USE_REGISTERED_RING</tt>.		<tt>IORING_SETUP_REGISTERED_FD_ONLY</tt> registers the ring fd for use with <tt>IORING_REGISTER_USE_REGISTERED_RING</tt>.

			<tt>io_uring_prep_cmd_sock(2)</tt> configures <tt>IORING_OP_URING_CMD</tt> SQEs to perform <tt>setsockopt(2)</tt> operations.

	==See also==		==See also==
	* [https://elixir.bootlin.com/linux/latest/source/Documentation/networking/af_xdp.rst AF_XDP] kernel documentation		* [https://elixir.bootlin.com/linux/latest/source/Documentation/networking/af_xdp.rst AF_XDP] kernel documentation