No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Joe Damato 25118cce66 tg3: Link IRQs to NAPI instances
Link IRQs to NAPI instances with netif_napi_set_irq. This information
can be queried with the netdev-genl API.

Begin by testing my tg3 device in its default state: 1 TX queue and 4 RX
queues.

Compare the output of /proc/interrupts for my tg3 device with the output of
netdev-genl after applying this patch:

$ cat /proc/interrupts | grep eth0
343: [...] eth0-tx-0
344: [...] eth0-rx-1
345: [...] eth0-rx-2
346: [...] eth0-rx-3
347: [...] eth0-rx-4

As you can see above, tg3 has named the IRQs such that there is a
dedicated tx IRQ and 4 dedicated rx IRQs, for a total of 5 IRQs.

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
			 --dump napi-get --json='{"ifindex": 2}'

[{'id': 8197, 'ifindex': 2, 'irq': 347},
 {'id': 8196, 'ifindex': 2, 'irq': 346},
 {'id': 8195, 'ifindex': 2, 'irq': 345},
 {'id': 8194, 'ifindex': 2, 'irq': 344},
 {'id': 8193, 'ifindex': 2, 'irq': 343}]

Netlink displays the same IRQs as above, noting that each is mapped to a
unique NAPI instance.

Now, reconfigure the NIC to have 4 TX queues and 4 RX queues:

$ sudo ethtool -L eth0 rx 4 tx 4
$ sudo ethtool -l eth0 | tail -5
Current hardware settings:
RX:		4
TX:		4
Other:		n/a
Combined:	n/a

Examine /proc/interrupts once again, noting that tg3 will now rename the
IRQs to suggest that they are combined tx and rx without allocating
additional IRQs, so the total IRQ count in /proc/interrupts is
unchanged:

343: [...] eth0-0
344: [...] eth0-txrx-1
345: [...] eth0-txrx-2
346: [...] eth0-txrx-3
347: [...] eth0-txrx-4

Check the output from netlink again:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump napi-get --json='{"ifindex": 2}'
[{'id': 8973, 'ifindex': 2, 'irq': 347},
 {'id': 8972, 'ifindex': 2, 'irq': 346},
 {'id': 8971, 'ifindex': 2, 'irq': 345},
 {'id': 8970, 'ifindex': 2, 'irq': 344},
 {'id': 8969, 'ifindex': 2, 'irq': 343}]

Signed-off-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20241009175509.31753-2-jdamato@fastly.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
History 2024-10-10 18:40:29 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-10 13:13:33 -07:00
block block-6.12-20241004 2024-10-04 10:43:44 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-10 13:13:33 -07:00
drivers
fs for-6.12-rc2-tag 2024-10-10 10:02:59 -07:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-10 13:13:33 -07:00
init cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig 2024-09-26 21:27:27 +02:00
io_uring io_uring/net: harden multishot termination case for recv 2024-09-30 08:26:59 -06:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel ring-buffer: Fix for 6.12 2024-10-10 12:25:32 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-10 13:13:33 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm mm: zswap: delete comments for "value" member of 'struct zswap_entry'. 2024-10-09 12:47:19 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-10 13:13:33 -07:00
rust Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-10 13:13:33 -07:00
samples [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
scripts kbuild: deb-pkg: Remove blank first line from maint scripts 2024-10-07 02:36:38 +09:00
security bcachefs: do not use PF_MEMALLOC_NORECLAIM 2024-10-09 12:47:18 -07:00
sound sound fixes for 6.12-rc2 2024-10-04 11:29:46 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-10 13:13:33 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt x86: 2024-09-28 09:20:14 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap .mailmap: update Fangrui's email 2024-10-09 12:47:19 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CREDITS: sort alphabetically by name 2024-10-09 12:47:19 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-10-10 13:13:33 -07:00
Makefile Linux 6.12-rc2 2024-10-06 15:32:27 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.