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On long-running enterprise production servers, high-order contiguous
memory pages are usually very rare and in most cases we can only get
fragmented pages.
When replacing TCP with SMC-R in such production scenarios, attempting
to allocate high-order physically contiguous sndbufs and RMBs may result
in frequent memory compaction, which will cause unexpected hung issue
and further stability risks.
So this patch is aimed to allow SMC-R link group to use virtually
contiguous sndbufs and RMBs to avoid potential issues mentioned above.
Whether to use physically or virtually contiguous buffers can be set
by sysctl smcr_buf_type.
Note that using virtually contiguous buffers will bring an acceptable
performance regression, which can be mainly divided into two parts:
1) regression in data path, which is brought by additional address
translation of sndbuf by RNIC in Tx. But in general, translating
address through MTT is fast.
Taking 256KB sndbuf and RMB as an example, the comparisons in qperf
latency and bandwidth test with physically and virtually contiguous
buffers are as follows:
- client:
smc_run taskset -c <cpu> qperf <server> -oo msg_size:1:64K:*2\
-t 5 -vu tcp_{bw|lat}
- server:
smc_run taskset -c <cpu> qperf
[latency]
msgsize tcp smcr smcr-use-virt-buf
1 11.17 us 7.56 us 7.51 us (-0.67%)
2 10.65 us 7.74 us 7.56 us (-2.31%)
4 11.11 us 7.52 us 7.59 us ( 0.84%)
8 10.83 us 7.55 us 7.51 us (-0.48%)
16 11.21 us 7.46 us 7.51 us ( 0.71%)
32 10.65 us 7.53 us 7.58 us ( 0.61%)
64 10.95 us 7.74 us 7.80 us ( 0.76%)
128 11.14 us 7.83 us 7.87 us ( 0.47%)
256 10.97 us 7.94 us 7.92 us (-0.28%)
512 11.23 us 7.94 us 8.20 us ( 3.25%)
1024 11.60 us 8.12 us 8.20 us ( 0.96%)
2048 14.04 us 8.30 us 8.51 us ( 2.49%)
4096 16.88 us 9.13 us 9.07 us (-0.64%)
8192 22.50 us 10.56 us 11.22 us ( 6.26%)
16384 28.99 us 12.88 us 13.83 us ( 7.37%)
32768 40.13 us 16.76 us 16.95 us ( 1.16%)
65536 68.70 us 24.68 us 24.85 us ( 0.68%)
[bandwidth]
msgsize tcp smcr smcr-use-virt-buf
1 1.65 MB/s 1.59 MB/s 1.53 MB/s (-3.88%)
2 3.32 MB/s 3.17 MB/s 3.08 MB/s (-2.67%)
4 6.66 MB/s 6.33 MB/s 6.09 MB/s (-3.85%)
8 13.67 MB/s 13.45 MB/s 11.97 MB/s (-10.99%)
16 25.36 MB/s 27.15 MB/s 24.16 MB/s (-11.01%)
32 48.22 MB/s 54.24 MB/s 49.41 MB/s (-8.89%)
64 106.79 MB/s 107.32 MB/s 99.05 MB/s (-7.71%)
128 210.21 MB/s 202.46 MB/s 201.02 MB/s (-0.71%)
256 400.81 MB/s 416.81 MB/s 393.52 MB/s (-5.59%)
512 746.49 MB/s 834.12 MB/s 809.99 MB/s (-2.89%)
1024 1292.33 MB/s 1641.96 MB/s 1571.82 MB/s (-4.27%)
2048 2007.64 MB/s 2760.44 MB/s 2717.68 MB/s (-1.55%)
4096 2665.17 MB/s 4157.44 MB/s 4070.76 MB/s (-2.09%)
8192 3159.72 MB/s 4361.57 MB/s 4270.65 MB/s (-2.08%)
16384 4186.70 MB/s 4574.13 MB/s 4501.17 MB/s (-1.60%)
32768 4093.21 MB/s 4487.42 MB/s 4322.43 MB/s (-3.68%)
65536 4057.14 MB/s 4735.61 MB/s 4555.17 MB/s (-3.81%)
2) regression in buffer initialization and destruction path, which is
brought by additional MR operations of sndbufs. But thanks to link
group buffer reuse mechanism, the impact of this kind of regression
decreases as times of buffer reuse increases.
Taking 256KB sndbuf and RMB as an example, latency of some key SMC-R
buffer-related function obtained by bpftrace are as follows:
Function Phys-bufs Virt-bufs
smcr_new_buf_create() 67154 ns 79164 ns
smc_ib_buf_map_sg() 525 ns 928 ns
smc_ib_get_memory_region() 162294 ns 161191 ns
smc_wr_reg_send() 9957 ns 9635 ns
smc_ib_put_memory_region() 203548 ns 198374 ns
smc_ib_buf_unmap_sg() 508 ns 1158 ns
------------
Test environment notes:
1. Above tests run on 2 VMs within the same Host.
2. The NIC is ConnectX-4Lx, using SRIOV and passing through 2 VFs to
the each VM respectively.
3. VMs' vCPUs are binded to different physical CPUs, and the binded
physical CPUs are isolated by `isolcpus=xxx` cmdline.
4. NICs' queue number are set to 1.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch introduces a new SMC-R specific element buf_type
in struct smc_link_group, for recording the value of sysctl
smcr_buf_type when link group is created.
New created link group will create and reuse buffers of the
type specified by buf_type.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch introduces the sysctl smcr_buf_type for setting
the type of SMC-R sndbufs and RMBs.
Valid values includes:
- SMCR_PHYS_CONT_BUFS, which means use physically contiguous
buffers for better performance and is the default value.
- SMCR_VIRT_CONT_BUFS, which means use virtually contiguous
buffers in case of physically contiguous memory is scarce.
- SMCR_MIXED_BUFS, which means first try to use physically
contiguous buffers. If not available, then use virtually
contiguous buffers.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some CPU, such as Xeon, can guarantee DMA cache coherency.
So it is no need to use dma sync APIs to flush cache on such CPUs.
In order to avoid calling dma sync APIs on the IO path, use the
dma_need_sync to check whether smc_buf_desc needs dma sync when
creating smc_buf_desc.
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
smc_ib_sync_sg_for_cpu/device are the ops used for dma memory cache
consistency. Smc sndbufs are dma buffers, where CPU writes data to
it and PCIE device reads data from it. So for sndbufs,
smc_ib_sync_sg_for_device is needed and smc_ib_sync_sg_for_cpu is
redundant as PCIE device will not write the buffers. Smc rmbs
are dma buffers, where PCIE device write data to it and CPU read
data from it. So for rmbs, smc_ib_sync_sg_for_cpu is needed and
smc_ib_sync_sg_for_device is redundant as CPU will not write the buffers.
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We encountered some crashes caused by the race between SMC-R
link access and link clear that triggered by abnormal link
group termination, such as port error.
Here is an example of this kind of crashes:
BUG: kernel NULL pointer dereference, address: 0000000000000000
Workqueue: smc_hs_wq smc_listen_work [smc]
RIP: 0010:smc_llc_flow_initiate+0x44/0x190 [smc]
Call Trace:
<TASK>
? __smc_buf_create+0x75a/0x950 [smc]
smcr_lgr_reg_rmbs+0x2a/0xbf [smc]
smc_listen_work+0xf72/0x1230 [smc]
? process_one_work+0x25c/0x600
process_one_work+0x25c/0x600
worker_thread+0x4f/0x3a0
? process_one_work+0x600/0x600
kthread+0x15d/0x1a0
? set_kthread_struct+0x40/0x40
ret_from_fork+0x1f/0x30
</TASK>
smc_listen_work() __smc_lgr_terminate()
---------------------------------------------------------------
| smc_lgr_free()
| |- smcr_link_clear()
| |- memset(lnk, 0)
smc_listen_rdma_reg() |
|- smcr_lgr_reg_rmbs() |
|- smc_llc_flow_initiate() |
|- access lnk->lgr (panic) |
These crashes are similarly caused by clearing SMC-R link
resources when some functions is still accessing to them.
This patch tries to fix the issue by introducing reference
count of SMC-R links and ensuring that the sensitive resources
of links won't be cleared until reference count reaches zero.
The operation to the SMC-R link reference count can be concluded
as follows:
object [hold or initialized as 1] [put]
--------------------------------------------------------------------
links smcr_link_init() smcr_link_clear()
connections smc_conn_create() smc_conn_free()
Through this way, the clear of SMC-R links is later than the
free of all the smc connections above it, thus avoiding the
unsafe reference to SMC-R links.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is no longer suitable to identify whether a smc connection
is registered in a link group through checking if conn->lgr
is NULL, because conn->lgr won't be reset even the connection
is unregistered from a link group.
So this patch introduces a new helper smc_conn_lgr_valid() and
replaces all the check of conn->lgr in original implementation
with the new helper to judge if conn->lgr is valid to use.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We encountered some crashes caused by the race between the access
and the termination of link groups.
Here are some of panic stacks we met:
1) Race between smc_clc_wait_msg() and __smc_lgr_terminate()
BUG: kernel NULL pointer dereference, address: 00000000000002f0
Workqueue: smc_hs_wq smc_listen_work [smc]
RIP: 0010:smc_clc_wait_msg+0x3eb/0x5c0 [smc]
Call Trace:
<TASK>
? smc_clc_send_accept+0x45/0xa0 [smc]
? smc_clc_send_accept+0x45/0xa0 [smc]
smc_listen_work+0x783/0x1220 [smc]
? finish_task_switch+0xc4/0x2e0
? process_one_work+0x1ad/0x3c0
process_one_work+0x1ad/0x3c0
worker_thread+0x4c/0x390
? rescuer_thread+0x320/0x320
kthread+0x149/0x190
? set_kthread_struct+0x40/0x40
ret_from_fork+0x1f/0x30
</TASK>
smc_listen_work() abnormal case like port error
---------------------------------------------------------------
| __smc_lgr_terminate()
| |- smc_conn_kill()
| |- smc_lgr_unregister_conn()
| |- set conn->lgr = NULL
smc_clc_wait_msg() |
|- access conn->lgr (panic) |
2) Race between smc_setsockopt() and __smc_lgr_terminate()
BUG: kernel NULL pointer dereference, address: 00000000000002e8
RIP: 0010:smc_setsockopt+0x17a/0x280 [smc]
Call Trace:
<TASK>
__sys_setsockopt+0xfc/0x190
__x64_sys_setsockopt+0x20/0x30
do_syscall_64+0x34/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
</TASK>
smc_setsockopt() abnormal case like port error
--------------------------------------------------------------
| __smc_lgr_terminate()
| |- smc_conn_kill()
| |- smc_lgr_unregister_conn()
| |- set conn->lgr = NULL
mod_delayed_work() |
|- access conn->lgr (panic) |
There are some other panic places and they are caused by the
similar reason as described above, which is accessing link
group after termination, thus getting a NULL pointer or invalid
resource.
Currently, there seems to be no synchronization between the
link group access and a sudden termination of it. This patch
tries to fix this by introducing reference count of link group
and not freeing link group until reference count is zero.
Link group might be referred to by links or smc connections. So
the operation to the link group reference count can be concluded
as follows:
object [hold or initialized as 1] [put]
-------------------------------------------------------------------
link group smc_lgr_create() smc_lgr_free()
connections smc_conn_create() smc_conn_free()
links smcr_link_init() smcr_link_clear()
Througth this way, we extend the life cycle of link group and
ensure it is longer than the life cycle of connections and links
above it, so that avoid invalid access to link group after its
termination.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMC connections might fail to be registered in a link group due to
unable to find a usable link during its creation. As a result,
smc_conn_create() will return a failure and most resources related
to the connection won't be applied or initialized, such as
conn->abort_work or conn->lnk.
If smc_conn_free() is invoked later, it will try to access the
uninitialized resources related to the connection, thus causing
a warning or crash.
This patch tries to fix this by resetting conn->lgr to NULL if an
abnormal exit occurs in smc_lgr_register_conn(), thus avoiding the
access to uninitialized resources in smc_conn_free().
Meanwhile, the new created link group should be terminated if smc
connections can't be registered in it. So smc_lgr_cleanup_early() is
modified to take care of link group only and invoked to terminate
unusable link group by smc_conn_create(). The call to smc_conn_free()
is moved out from smc_lgr_cleanup_early() to smc_conn_abort().
Fixes: 56bc3b2094 ("net/smc: assign link to a new connection")
Suggested-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add comments for both smc_link_sendable() and smc_link_usable()
to help better distinguish and use them.
No function changes.
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, rdma device supports exclusive net namespace isolation,
however linkgroup doesn't know and support ibdev net namespace.
Applications in the containers don't want to share the nics if we
enabled rdma exclusive mode. Every net namespaces should have their own
linkgroups.
This patch introduce a new field net for linkgroup, which is standing
for the ibdev net namespace in the linkgroup. The net in linkgroup is
initialized with the net namespace of link's ibdev. It compares the net
of linkgroup and sock or ibdev before choose it, if no matched, create
new one in current net namespace. If rdma net namespace exclusive mode
is not enabled, it behaves as before.
Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We found smc_llc_send_link_delete_all() sometimes wait
for 2s timeout when testing with RDMA link up/down.
It is possible when a smc_link is in ACTIVATING state,
the underlaying QP is still in RESET or RTR state, which
cannot send any messages out.
smc_llc_send_link_delete_all() use smc_link_usable() to
checks whether the link is usable, if the QP is still in
RESET or RTR state, but the smc_link is in ACTIVATING, this
LLC message will always fail without any CQE entering the
CQ, and we will always wait 2s before timeout.
Since we cannot send any messages through the QP before
the QP enter RTS. I add a wrapper smc_link_sendable()
which checks the state of QP along with the link state.
And replace smc_link_usable() with smc_link_sendable()
in all LLC & CDC message sending routine.
Fixes: 5f08318f61 ("smc: connection data control (CDC)")
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for large v2 LLC control messages in smc_llc.c.
The new large work request buffer allows to combine control
messages into one packet that had to be spread over several
packets before.
Add handling of the new v2 LLC messages.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the work request layer define one large v2 buffer for each link group
that is used to transmit and receive large LLC control messages.
Add the completion queue handling for this buffer.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement the server side of the SMC-Rv2 processing. Process incoming
CLC messages, find eligible devices and check for a valid route to the
remote peer.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Send a CLC proposal message, and the remote side process this type of
message and determine the target GID. Check for a valid route to this
GID, and complete the connection establishment.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Prepare the connection establishment with SMC-Rv2. Detect eligible
RoCE cards and indicate all supported SMC modes for the connection.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMC-Dv2 allows users to define EIDs which allows to create separate
name spaces enabling users to cluster their SMC-Dv2 connections.
Add support for user defined EIDs and extent the generic netlink
interface so users can add, remove and dump EIDs.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMC clients may be assigned to a different link after the initial
connection between two peers was established. In such a case,
the connection counter was not correctly set.
Update the connection counter correctly when a smc client connection
is assigned to a different smc link.
Fixes: 07d51580ff ("net/smc: Add connection counters for links")
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Tested-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There can be a race between the waiters for a tx work request buffer
and the link down processing that finally clears the link. Although
all waiters are woken up before the link is cleared there might be
waiters which did not yet get back control and are still waiting.
This results in an access to a cleared wait queue head.
Fix this by introducing atomic reference counting around the wait calls,
and wait with the link clear processing until all waiters have finished.
Move the work request layer related calls into smc_wr.c and set the
link state to INACTIVE before calling smcr_link_clear() in
smc_llc_srv_add_link().
Fixes: 15e1b99aad ("net/smc: no WR buffer wait for terminating link group")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct smc_clc_msg_local is declared twice. One is declared at
301st line. The blew one is not needed. Remove the duplicate.
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce get link command which loops through
all available links of all available link groups. It
uses the SMC-R linkgroup list as entry point, not
the socket list, which makes linkgroup diagnosis
possible, in case linkgroup does not contain active
connections anymore.
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce get linkgroup command which loops through
all available SMCR linkgroups. It uses the SMC-R linkgroup
list as entry point, not the socket list, which makes
linkgroup diagnosis possible, in case linkgroup does not
contain active connections anymore.
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add new netlink command to obtain system information
of the smc module.
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
During link creation add net-device ifindex and ib-device
name to link structure. This is needed for diagnostic purposes.
When diagnostic information is gathered, we need to traverse
device, linkgroup and link structures, to be able to do that
we need to hold a spinlock for the linkgroup list, without this
diagnostic information in link structure, another device list
mutex holding would be necessary to dereference the device
pointer in the link structure which would be impossible when
holding a spinlock already.
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add connection counters to the structure of the link.
Increase/decrease the counters as needed in the corresponding
routines.
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
To allow better problem diagnosis the return codes for SMC-Dv2 are
improved by this patch. A few more CLC DECLINE codes are defined and
sent to the peer when an SMC connection cannot be established.
There are now multiple SMC variations that are offered by the client and
the server may encounter problems to initialize all of them.
Because only one diagnosis code can be sent to the client the decision
was made to send the first code that was encountered. Because the server
tries the variations in the order of importance (SMC-Dv2, SMC-D, SMC-R)
this makes sure that the diagnosis code of the most important variation
is sent.
v2: initialize rc in smc_listen_v2_check().
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20201031181938.69903-1-kgraul@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
SMC Version 2 defines a first contact extension for CLC accept
and CLC confirm. This patch covers sending and receiving of the
CLC first contact extension.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMCD Version 2 allows to propose up to 8 additional ISM devices
offered to the peer as candidates for SMCD communication.
This patch covers the server side, i.e. selection of an ISM device
matching one of the proposed ISM devices, that will be used for
CLC accept
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMCD Version 2 allows to propose up to 8 additional ISM devices
offered to the peer as candidates for SMCD communication.
This patch covers determination of the ISM devices to be proposed.
ISM devices without PNETID are preferred, since ISM devices with
PNETID are a V1 leftover and will disappear over the time.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With SMCD version 2 the CHIDs of ISM devices are needed for the
CLC handshake.
This patch provides the new callback to retrieve the CHID of an
ISM device.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMCD Version 2 allows proposing of up to 8 ISM devices in addition
to the native ISM device of SMCD Version 1.
This patch prepares the struct smc_init_info to deal with these
additional 8 ISM devices.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are 6 types of workers which exist per smc connection. 3 of them
are used for listen and handshake processing, another 2 are used for
close and abort processing and 1 is the tx worker that moves calls to
sleeping functions into a worker.
To prevent flooding of the system work queue when many connections are
opened or closed at the same time (some pattern uperf implements), move
those workers to one of 3 smc-specific work queues. Two work queues are
module-global and used for handshake and close workers. The third work
queue is defined per link group and used by the tx workers that may
sleep waiting for resources of this link group.
And in smc_llc_enqueue() queue the llc_event_work work to the system
prio work queue because its critical that this work is started fast.
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
smc_lgr_cleanup_early() schedules the free worker with delay. DMB
unregistering occurs in this delayed worker increasing the risk
to reach the SMCD SBA limit without need. Terminate the
linkgroup immediately, since termination means early DMB unregistering.
For SMCD the global smc_server_lgr_pending lock is given up early.
A linkgroup to be given up with smc_lgr_cleanup_early() may already
contain more than one connection. Using __smc_lgr_terminate() in
smc_lgr_cleanup_early() covers this.
And consolidate smc_ism_put_vlan() and smc_put_device() into smc_lgr_free()
only.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Field names "srv_first_contact" and "cln_first_contact" are misleading,
since they apply to both, server and client. Rename them to
"first_contact_peer" and "first_contact_local".
Rename "ism_gid" by the more precise name "ism_peer_gid".
Rename version constant "SMC_CLC_V1" into "SMC_V1".
No functional change.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The dma related ...sync_sg... functions check the link state before the
dma function is actually called. But the check in smc_link_usable()
allows links in ACTIVATING state which are not yet mapped to dma memory.
Under high load it may happen that the sync_sg functions are called for
such a link which results in an debug output like
DMA-API: mlx5_core 0002:00:00.0: device driver tries to sync
DMA memory it has not allocated [device address=0x0000000103370000]
[size=65536 bytes]
To fix that introduce a helper to check for the link state ACTIVE and
use it where appropriate. And move the link state update to ACTIVATING
to the end of smcr_link_init() when most initial setup is done.
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Fixes: d854fcbfae ("net/smc: add new link state and related helpers")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There might be races in scenarios where both SMC link groups are on the
same system. Prevent that by creating separate wait queues for LLC flows
and messages. Switch to non-interruptable versions of wait_event() and
wake_up() for the llc flow waiter to make sure the waiters get control
sequentially. Fine tune the llc_flow_lock to include the assignment of
the message. Write to system log when an unexpected message was
dropped. And remove an extra indirection and use the existing local
variable lgr in smc_llc_enqueue().
Fixes: 555da9af82 ("net/smc: add event-based llc_flow framework")
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Print to system log when SMC links are available or go down, link group
state changes or pnetids are applied to and removed from devices.
The log entries are triggered by either user configuration actions or
adapter activation/deactivation events and are not expected to happen
often. The entries help SMC users to keep track of the SMC link group
status and to detect when actions are needed (like to add replacements
for failed adapters).
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During SMC-R link establishment the peers exchange the link_uid that
is used for debugging purposes. Save the peer link_uid in smc_link so it
can be retrieved by the smc_diag netlink interface.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The link_uid of an SMC-R link is exchanged between SMC peers and its
value can be used for debugging purposes. Create a unique link_uid
during link initialization and use it in communication with SMC-R peers.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow to set the reason code for the link group termination, and set
meaningful values before termination processing is triggered. This
reason code is sent to the peer in the final delete link message.
When the LLC request or response layer receives a message type that was
not handled, drop a warning and terminate the link group.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
New connections must not be assigned to asymmetric links. Add asymmetric
link tagging using new link variable link_is_asym. The new helpers
smcr_lgr_set_type() and smcr_lgr_set_type_asym() are called to set the
state of the link group, and tag all links accordingly.
smcr_lgr_conn_assign_link() respects the link tagging and will not
assign new connections to links tagged as asymmetric link.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce smc_wr_tx_send_wait() to send an IB message and wait for the
tx completion event of the message. This makes sure that the message is
no longer in-flight when the function returns.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add smc_switch_conns() to switch all connections from a link that is
going down. Find an other link to switch the connections to, and
switch each connection to the new link. smc_switch_cursor() updates the
cursors of a connection to the state of the last successfully sent CDC
message. When there is no link to switch to, terminate the link group.
Call smc_switch_conns() when a link is going down.
And with the possibility that links of connections can switch adapt CDC
and TX functions to detect and handle link switches.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce a work that is scheduled when a new DELETE_LINK LLC request is
received. The work will call either the SMC client or SMC server
DELETE_LINK processing.
And use the LLC flow framework to process incoming DELETE_LINK LLC
messages, scheduling the llc_del_link_work for those events.
With these changes smc_lgr_forget() is only called by one function and
can be migrated into smc_lgr_cleanup_early().
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
First set of functions to process an ADD_LINK LLC request as an SMC
client. Find an alternate IB device, determine the new link group type
and get the index for the new link. Then ready the link, map the buffers
and send an ADD_LINK LLC response. If any error occurs, send a reject
LLC message and terminate the processing.
Add smc_llc_alloc_alt_link() to find a free link index for a new link,
depending on the new link group type.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
