diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /Documentation/networking/smc-sysctl.rst | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'Documentation/networking/smc-sysctl.rst')
| -rw-r--r-- | Documentation/networking/smc-sysctl.rst | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/Documentation/networking/smc-sysctl.rst b/Documentation/networking/smc-sysctl.rst new file mode 100644 index 000000000..93cc6244f --- /dev/null +++ b/Documentation/networking/smc-sysctl.rst @@ -0,0 +1,140 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========== +SMC Sysctl +========== + +/proc/sys/net/smc/* Variables +============================= + +autocorking_size - INTEGER + Setting SMC auto corking size: + SMC auto corking is like TCP auto corking from the application's + perspective of view. When applications do consecutive small + write()/sendmsg() system calls, we try to coalesce these small writes + as much as possible, to lower total amount of CDC and RDMA Write been + sent. + autocorking_size limits the maximum corked bytes that can be sent to + the under device in 1 single sending. If set to 0, the SMC auto corking + is disabled. + Applications can still use TCP_CORK for optimal behavior when they + know how/when to uncork their sockets. + + Default: 64K + +smcr_buf_type - INTEGER + Controls which type of sndbufs and RMBs to use in later newly created + SMC-R link group. Only for SMC-R. + + Default: 0 (physically contiguous sndbufs and RMBs) + + Possible values: + + - 0 - Use physically contiguous buffers + - 1 - Use virtually contiguous buffers + - 2 - Mixed use of the two types. Try physically contiguous buffers first. + If not available, use virtually contiguous buffers then. + +smcr_testlink_time - INTEGER + How frequently SMC-R link sends out TEST_LINK LLC messages to confirm + viability, after the last activity of connections on it. Value 0 means + disabling TEST_LINK. + + Default: 30 seconds. + +wmem - INTEGER + Initial size of send buffer used by SMC sockets. + + The minimum value is 16KiB and there is no hard limit for max value, but + only allowed 512KiB for SMC-R and 1MiB for SMC-D. + + Default: 64KiB + +rmem - INTEGER + Initial size of receive buffer (RMB) used by SMC sockets. + + The minimum value is 16KiB and there is no hard limit for max value, but + only allowed 512KiB for SMC-R and 1MiB for SMC-D. + + Default: 64KiB + +smcr_max_links_per_lgr - INTEGER + Controls the max number of links can be added to a SMC-R link group. Notice that + the actual number of the links added to a SMC-R link group depends on the number + of RDMA devices exist in the system. The acceptable value ranges from 1 to 2. Only + for SMC-R v2.1 and later. + + Default: 2 + +smcr_max_conns_per_lgr - INTEGER + Controls the max number of connections can be added to a SMC-R link group. The + acceptable value ranges from 16 to 255. Only for SMC-R v2.1 and later. + + Default: 255 + +smcr_max_send_wr - INTEGER + So-called work request buffers are SMCR link (and RDMA queue pair) level + resources necessary for performing RDMA operations. Since up to 255 + connections can share a link group and thus also a link and the number + of the work request buffers is decided when the link is allocated, + depending on the workload it can be a bottleneck in a sense that threads + have to wait for work request buffers to become available. Before the + introduction of this control the maximal number of work request buffers + available on the send path used to be hard coded to 16. With this control + it becomes configurable. The acceptable range is between 2 and 2048. + + Please be aware that all the buffers need to be allocated as a physically + continuous array in which each element is a single buffer and has the size + of SMC_WR_BUF_SIZE (48) bytes. If the allocation fails, we keep retrying + with half of the buffer count until it is either successful or (unlikely) + we dip below the old hard coded value which is 16 where we give up much + like before having this control. + + Default: 16 + +smcr_max_recv_wr - INTEGER + So-called work request buffers are SMCR link (and RDMA queue pair) level + resources necessary for performing RDMA operations. Since up to 255 + connections can share a link group and thus also a link and the number + of the work request buffers is decided when the link is allocated, + depending on the workload it can be a bottleneck in a sense that threads + have to wait for work request buffers to become available. Before the + introduction of this control the maximal number of work request buffers + available on the receive path used to be hard coded to 48. With this control + it becomes configurable. The acceptable range is between 2 and 2048. + + Please be aware that all the buffers need to be allocated as a physically + continuous array in which each element is a single buffer and has the size + of SMC_WR_BUF_SIZE (48) bytes. If the allocation fails, we keep retrying + with half of the buffer count until it is either successful or (unlikely) + we dip below the old hard coded value which is 48 where we give up much + like before having this control. + + Default: 48 + +limit_smc_hs - INTEGER + Whether to limit SMC handshake for newly created sockets. + + When enabled, SMC listen path applies handshake limitation based on + handshake worker congestion and queued SMC handshake load. + + Possible values: + + - 0 - Disable handshake limitation + - 1 - Enable handshake limitation + + Default: 0 (disable) + +hs_ctrl - STRING + Select the SMC handshake control profile by name. + + This string refers to the name of a user-implemented + BPF struct_ops instance of type smc_hs_ctrl. + + The selected profile controls whether SMC options are advertised + during TCP SYN/SYN-ACK handshake. + + Only available when CONFIG_SMC_HS_CTRL_BPF is enabled. + Write an empty string to clear the current profile. + + Default: empty string |
