0227f058aa
Currently, SMC uses smc->sk.sk_{rcv|snd}buf to create buffers for
send buffer and RMB. And the values of buffer size are from tcp_{w|r}mem
in clcsock.
The buffer size from TCP socket doesn't fit SMC well. Generally, buffers
are usually larger than TCP for SMC-R/-D to get higher performance, for
they are different underlay devices and paths.
So this patch unbinds buffer size from TCP, and introduces two sysctl
knobs to tune them independently. Also, these knobs are per net
namespace and work for containers.
Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
62 lines
1.9 KiB
ReStructuredText
62 lines
1.9 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
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==========
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SMC Sysctl
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==========
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/proc/sys/net/smc/* Variables
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=============================
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autocorking_size - INTEGER
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Setting SMC auto corking size:
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SMC auto corking is like TCP auto corking from the application's
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perspective of view. When applications do consecutive small
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write()/sendmsg() system calls, we try to coalesce these small writes
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as much as possible, to lower total amount of CDC and RDMA Write been
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sent.
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autocorking_size limits the maximum corked bytes that can be sent to
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the under device in 1 single sending. If set to 0, the SMC auto corking
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is disabled.
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Applications can still use TCP_CORK for optimal behavior when they
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know how/when to uncork their sockets.
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Default: 64K
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smcr_buf_type - INTEGER
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Controls which type of sndbufs and RMBs to use in later newly created
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SMC-R link group. Only for SMC-R.
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Default: 0 (physically contiguous sndbufs and RMBs)
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Possible values:
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- 0 - Use physically contiguous buffers
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- 1 - Use virtually contiguous buffers
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- 2 - Mixed use of the two types. Try physically contiguous buffers first.
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If not available, use virtually contiguous buffers then.
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smcr_testlink_time - INTEGER
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How frequently SMC-R link sends out TEST_LINK LLC messages to confirm
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viability, after the last activity of connections on it. Value 0 means
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disabling TEST_LINK.
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Default: 30 seconds.
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wmem - INTEGER
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Initial size of send buffer used by SMC sockets.
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The default value inherits from net.ipv4.tcp_wmem[1].
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The minimum value is 16KiB and there is no hard limit for max value, but
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only allowed 512KiB for SMC-R and 1MiB for SMC-D.
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Default: 16K
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rmem - INTEGER
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Initial size of receive buffer (RMB) used by SMC sockets.
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The default value inherits from net.ipv4.tcp_rmem[1].
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The minimum value is 16KiB and there is no hard limit for max value, but
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only allowed 512KiB for SMC-R and 1MiB for SMC-D.
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Default: 128K
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