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2023-11-24net/smc: remove unneeded atomic operations in smc_tx_sndbuf_nonemptyLi RongQing
The commit dcd2cf5f2fc0 ("net/smc: add autocorking support") adds an atomic variable tx_pushing in smc_connection to make sure only one can send to let it cork more and save CDC slot. since smc_tx_pending can be called in the soft IRQ without checking sock_owned_by_user() at that time, which would cause a race condition because bh_lock_sock() did not honor sock_lock() After commit 6b88af839d20 ("net/smc: don't send in the BH context if sock_owned_by_user"), the transmission is deferred to when sock_lock() is held by the user. Therefore, we no longer need tx_pending to hold message. So remove atomic variable tx_pushing and its operation, and smc_tx_sndbuf_nonempty becomes a wrapper of __smc_tx_sndbuf_nonempty, so rename __smc_tx_sndbuf_nonempty back to smc_tx_sndbuf_nonempty Suggested-by: Alexandra Winter <wintera@linux.ibm.com> Co-developed-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> diff v4: remove atomic variable tx_pushing diff v3: improvements in the commit body and comments diff v2: fix a typo in commit body and add net-next subject-prefix net/smc/smc.h | 1 - net/smc/smc_tx.c | 30 +----------------------------- 2 files changed, 1 insertion(+), 30 deletions(-) Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-24smc: Drop smc_sendpage() in favour of smc_sendmsg() + MSG_SPLICE_PAGESDavid Howells
Drop the smc_sendpage() code as smc_sendmsg() just passes the call down to the underlying TCP socket and smc_tx_sendpage() is just a wrapper around its sendmsg implementation. Signed-off-by: David Howells <dhowells@redhat.com> cc: Karsten Graul <kgraul@linux.ibm.com> cc: Wenjia Zhang <wenjia@linux.ibm.com> cc: Jan Karcher <jaka@linux.ibm.com> cc: "D. Wythe" <alibuda@linux.alibaba.com> cc: Tony Lu <tonylu@linux.alibaba.com> cc: Wen Gu <guwen@linux.alibaba.com> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Link: https://lore.kernel.org/r/20230623225513.2732256-10-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-24tcp_bpf, smc, tls, espintcp, siw: Reduce MSG_SENDPAGE_NOTLAST usageDavid Howells
As MSG_SENDPAGE_NOTLAST is being phased out along with sendpage(), don't use it further in than the sendpage methods, but rather translate it to MSG_MORE and use that instead. Signed-off-by: David Howells <dhowells@redhat.com> cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> cc: Bernard Metzler <bmt@zurich.ibm.com> cc: Jason Gunthorpe <jgg@ziepe.ca> cc: Leon Romanovsky <leon@kernel.org> cc: John Fastabend <john.fastabend@gmail.com> cc: Jakub Sitnicki <jakub@cloudflare.com> cc: David Ahern <dsahern@kernel.org> cc: Karsten Graul <kgraul@linux.ibm.com> cc: Wenjia Zhang <wenjia@linux.ibm.com> cc: Jan Karcher <jaka@linux.ibm.com> cc: "D. Wythe" <alibuda@linux.alibaba.com> cc: Tony Lu <tonylu@linux.alibaba.com> cc: Wen Gu <guwen@linux.alibaba.com> cc: Boris Pismenny <borisp@nvidia.com> cc: Steffen Klassert <steffen.klassert@secunet.com> cc: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/20230623225513.2732256-2-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10net: deal with most data-races in sk_wait_event()Eric Dumazet
__condition is evaluated twice in sk_wait_event() macro. First invocation is lockless, and reads can race with writes, as spotted by syzbot. BUG: KCSAN: data-race in sk_stream_wait_connect / tcp_disconnect write to 0xffff88812d83d6a0 of 4 bytes by task 9065 on cpu 1: tcp_disconnect+0x2cd/0xdb0 inet_shutdown+0x19e/0x1f0 net/ipv4/af_inet.c:911 __sys_shutdown_sock net/socket.c:2343 [inline] __sys_shutdown net/socket.c:2355 [inline] __do_sys_shutdown net/socket.c:2363 [inline] __se_sys_shutdown+0xf8/0x140 net/socket.c:2361 __x64_sys_shutdown+0x31/0x40 net/socket.c:2361 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88812d83d6a0 of 4 bytes by task 9040 on cpu 0: sk_stream_wait_connect+0x1de/0x3a0 net/core/stream.c:75 tcp_sendmsg_locked+0x2e4/0x2120 net/ipv4/tcp.c:1266 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1484 inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:651 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x246/0x300 net/socket.c:2142 __do_sys_sendto net/socket.c:2154 [inline] __se_sys_sendto net/socket.c:2150 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2150 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000000 -> 0x00000068 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-11-25use less confusing names for iov_iter direction initializersAl Viro
READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-07-27net/smc: Eliminate struct smc_ism_positionHeiko Carstens
This struct is used in a single place only, and its usage generates inefficient code. Time to clean up! Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-and-tested-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Wenjia Zhang < wenjia@linux.ibm.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18net/smc: Allow virtually contiguous sndbufs or RMBs for SMC-RWen Gu
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>
2022-07-18net/smc: remove redundant dma sync opsGuangguan Wang
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>
2022-05-17net/smc: rdma write inline if qp has sufficient inline spaceGuangguan Wang
Rdma write with inline flag when sending small packages, whose length is shorter than the qp's max_inline_data, can help reducing latency. In my test environment, which are 2 VMs running on the same physical host and whose NICs(ConnectX-4Lx) are working on SR-IOV mode, qperf shows 0.5us-0.7us improvement in latency. Test command: server: smc_run taskset -c 1 qperf client: smc_run taskset -c 1 qperf <server ip> -oo \ msg_size:1:2K:*2 -t 30 -vu tcp_lat The results shown below: msgsize before after 1B 11.2 us 10.6 us (-0.6 us) 2B 11.2 us 10.7 us (-0.5 us) 4B 11.3 us 10.7 us (-0.6 us) 8B 11.2 us 10.6 us (-0.6 us) 16B 11.3 us 10.7 us (-0.6 us) 32B 11.3 us 10.6 us (-0.7 us) 64B 11.2 us 11.2 us (0 us) 128B 11.2 us 11.2 us (0 us) 256B 11.2 us 11.2 us (0 us) 512B 11.4 us 11.3 us (-0.1 us) 1KB 11.4 us 11.5 us (0.1 us) 2KB 11.5 us 11.5 us (0 us) Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Tested-by: kernel test robot <lkp@intel.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-01net: smc: fix different types in min()Jakub Kicinski
Fix build: include/linux/minmax.h:45:25: note: in expansion of macro ‘__careful_cmp’ 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ net/smc/smc_tx.c:150:24: note: in expansion of macro ‘min’ 150 | corking_size = min(sock_net(&smc->sk)->smc.sysctl_autocorking_size, | ^~~ Fixes: 12bbb0d163a9 ("net/smc: add sysctl for autocorking") Link: https://lore.kernel.org/r/20220301222446.1271127-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-01net/smc: add sysctl for autocorkingDust Li
This add a new sysctl: net.smc.autocorking_size We can dynamically change the behaviour of autocorking by change the value of autocorking_size. Setting to 0 disables autocorking in SMC Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-01net/smc: add autocorking supportDust Li
This patch adds autocorking support for SMC which could improve throughput for small message by x3+. The main idea is borrowed from TCP autocorking with some RDMA specific modification: 1. The first message should never cork to make sure we won't bring extra latency 2. If we have posted any Tx WRs to the NIC that have not completed, cork the new messages until: a) Receive CQE for the last Tx WR b) We have corked enough message on the connection 3. Try to push the corked data out when we receive CQE of the last Tx WR to prevent the corked messages hang in the send queue. Both SMC autocorking and TCP autocorking check the TX completion to decide whether we should cork or not. The difference is when we got a SMC Tx WR completion, the data have been confirmed by the RNIC while TCP TX completion just tells us the data have been sent out by the local NIC. Add an atomic variable tx_pushing in smc_connection to make sure only one can send to let it cork more and save CDC slot. SMC autocorking should not bring extra latency since the first message will always been sent out immediately. The qperf tcp_bw test shows more than x4 increase under small message size with Mellanox connectX4-Lx, same result with other throughput benchmarks like sockperf/netperf. The qperf tcp_lat test shows SMC autocorking has not increase any ping-pong latency. Test command: client: smc_run taskset -c 1 qperf smc-server -oo msg_size:1:64K:*2 \ -t 30 -vu tcp_{bw|lat} server: smc_run taskset -c 1 qperf === Bandwidth ==== MsgSize(Bytes) SMC-NoCork TCP SMC-AutoCorking 1 0.578 MB/s 2.392 MB/s(313.57%) 2.647 MB/s(357.72%) 2 1.159 MB/s 4.780 MB/s(312.53%) 5.153 MB/s(344.71%) 4 2.283 MB/s 10.266 MB/s(349.77%) 10.363 MB/s(354.02%) 8 4.668 MB/s 19.040 MB/s(307.86%) 21.215 MB/s(354.45%) 16 9.147 MB/s 38.904 MB/s(325.31%) 41.740 MB/s(356.32%) 32 18.369 MB/s 79.587 MB/s(333.25%) 82.392 MB/s(348.52%) 64 36.562 MB/s 148.668 MB/s(306.61%) 161.564 MB/s(341.89%) 128 72.961 MB/s 274.913 MB/s(276.80%) 325.363 MB/s(345.94%) 256 144.705 MB/s 512.059 MB/s(253.86%) 633.743 MB/s(337.96%) 512 288.873 MB/s 884.977 MB/s(206.35%) 1250.681 MB/s(332.95%) 1024 574.180 MB/s 1337.736 MB/s(132.98%) 2246.121 MB/s(291.19%) 2048 1095.192 MB/s 1865.952 MB/s( 70.38%) 2057.767 MB/s( 87.89%) 4096 2066.157 MB/s 2380.337 MB/s( 15.21%) 2173.983 MB/s( 5.22%) 8192 3717.198 MB/s 2733.073 MB/s(-26.47%) 3491.223 MB/s( -6.08%) 16384 4742.221 MB/s 2958.693 MB/s(-37.61%) 4637.692 MB/s( -2.20%) 32768 5349.550 MB/s 3061.285 MB/s(-42.77%) 5385.796 MB/s( 0.68%) 65536 5162.919 MB/s 3731.408 MB/s(-27.73%) 5223.890 MB/s( 1.18%) ==== Latency ==== MsgSize(Bytes) SMC-NoCork TCP SMC-AutoCorking 1 10.540 us 11.938 us( 13.26%) 10.573 us( 0.31%) 2 10.996 us 11.992 us( 9.06%) 10.269 us( -6.61%) 4 10.229 us 11.687 us( 14.25%) 10.240 us( 0.11%) 8 10.203 us 11.653 us( 14.21%) 10.402 us( 1.95%) 16 10.530 us 11.313 us( 7.44%) 10.599 us( 0.66%) 32 10.241 us 11.586 us( 13.13%) 10.223 us( -0.18%) 64 10.693 us 11.652 us( 8.97%) 10.251 us( -4.13%) 128 10.597 us 11.579 us( 9.27%) 10.494 us( -0.97%) 256 10.409 us 11.957 us( 14.87%) 10.710 us( 2.89%) 512 11.088 us 12.505 us( 12.78%) 10.547 us( -4.88%) 1024 11.240 us 12.255 us( 9.03%) 10.787 us( -4.03%) 2048 11.485 us 16.970 us( 47.76%) 11.256 us( -1.99%) 4096 12.077 us 13.948 us( 15.49%) 12.230 us( 1.27%) 8192 13.683 us 16.693 us( 22.00%) 13.786 us( 0.75%) 16384 16.470 us 23.615 us( 43.38%) 16.459 us( -0.07%) 32768 22.540 us 40.966 us( 81.75%) 23.284 us( 3.30%) 65536 34.192 us 73.003 us(113.51%) 34.233 us( 0.12%) With SMC autocorking support, we can archive better throughput than TCP in most message sizes without any latency trade-off. Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-28net/smc: Call trace_smc_tx_sendmsg when data corkedTony Lu
This also calls trace_smc_tx_sendmsg() even if data is corked. For ease of understanding, if statements are not expanded here. Link: https://lore.kernel.org/all/f4166712-9a1e-51a0-409d-b7df25a66c52@linux.ibm.com/ Fixes: 139653bc6635 ("net/smc: Remove corked dealyed work") Suggested-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-14net/smc: Add comment for smc_tx_pendingTony Lu
The previous patch introduces a lock-free version of smc_tx_work() to solve unnecessary lock contention, which is expected to be held lock. So this adds comment to remind people to keep an eye out for locks. Suggested-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-31net/smc: Cork when sendpage with MSG_SENDPAGE_NOTLAST flagTony Lu
This introduces a new corked flag, MSG_SENDPAGE_NOTLAST, which is involved in syscall sendfile() [1], it indicates this is not the last page. So we can cork the data until the page is not specify this flag. It has the same effect as MSG_MORE, but existed in sendfile() only. This patch adds a option MSG_SENDPAGE_NOTLAST for corking data, try to cork more data before sending when using sendfile(), which acts like TCP's behaviour. Also, this reimplements the default sendpage to inform that it is supported to some extent. [1] https://man7.org/linux/man-pages/man2/sendfile.2.html Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-31net/smc: Remove corked dealyed workTony Lu
Based on the manual of TCP_CORK [1] and MSG_MORE [2], these two options have the same effect. Applications can set these options and informs the kernel to pend the data, and send them out only when the socket or syscall does not specify this flag. In other words, there's no need to send data out by a delayed work, which will queue a lot of work. This removes corked delayed work with SMC_TX_CORK_DELAY (250ms), and the applications control how/when to send them out. It improves the performance for sendfile and throughput, and remove unnecessary race of lock_sock(). This also unlocks the limitation of sndbuf, and try to fill it up before sending. [1] https://linux.die.net/man/7/tcp [2] https://man7.org/linux/man-pages/man2/send.2.html Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-31net/smc: Send directly when TCP_CORK is clearedTony Lu
According to the man page of TCP_CORK [1], if set, don't send out partial frames. All queued partial frames are sent when option is cleared again. When applications call setsockopt to disable TCP_CORK, this call is protected by lock_sock(), and tries to mod_delayed_work() to 0, in order to send pending data right now. However, the delayed work smc_tx_work is also protected by lock_sock(). There introduces lock contention for sending data. To fix it, send pending data directly which acts like TCP, without lock_sock() protected in the context of setsockopt (already lock_sock()ed), and cancel unnecessary dealyed work, which is protected by lock. [1] https://linux.die.net/man/7/tcp Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-01net/smc: Introduce tracepoints for tx and rx msgTony Lu
This introduce two tracepoints for smc tx and rx msg to help us diagnosis issues of data path. These two tracepoitns don't cover the path of CORK or MSG_MORE in tx, just the top half of data path. Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Reviewed-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-08net/smc: improved fix wait on already cleared linkKarsten Graul
Commit 8f3d65c16679 ("net/smc: fix wait on already cleared link") introduced link refcounting to avoid waits on already cleared links. This patch extents and improves the refcounting to cover all remaining possible cases for this kind of error situation. Fixes: 15e1b99aadfb ("net/smc: no WR buffer wait for terminating link group") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-09net/smc: fix wait on already cleared linkKarsten Graul
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: 15e1b99aadfb ("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>
2021-06-25net/smc: Ensure correct state of the socket in send pathGuvenc Gulce
When smc_sendmsg() is called before the SMC socket initialization has completed, smc_tx_sendmsg() will access un-initialized fields of the SMC socket which results in a null-pointer dereference. Fix this by checking the socket state first in smc_tx_sendmsg(). Fixes: e0e4b8fa5338 ("net/smc: Add SMC statistics support") Reported-by: syzbot+5dda108b672b54141857@syzkaller.appspotmail.com Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-16net/smc: Make SMC statistics network namespace awareGuvenc Gulce
Make the gathered SMC statistics network namespace aware, for each namespace collect an own set of statistic information. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-16net/smc: Add SMC statistics supportGuvenc Gulce
Add the ability to collect SMC statistics information. Per-cpu variables are used to collect the statistic information for better performance and for reducing concurrency pitfalls. The code that is collecting statistic data is implemented in macros to increase code reuse and readability. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10net/smc: use separate work queues for different worker typesKarsten Graul
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>
2020-05-04net/smc: switch connections to alternate linkKarsten Graul
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>
2020-05-01net/smc: take link down instead of terminating the link groupKarsten Graul
Use the introduced link down processing in all places where the link group is terminated and take down the affected link only. 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>
2020-04-29net/smc: convert static link ID to dynamic referencesKarsten Graul
As a preparation for the support of multiple links remove the usage of a static link id (SMC_SINGLE_LINK) and allow dynamic link ids. 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>
2020-02-17net/smc: use termination worker under send_lockKarsten Graul
smc_tx_rdma_write() is called under the send_lock and should not call smc_lgr_terminate() directly. Call smc_lgr_terminate_sched() instead which schedules a worker. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-15net/smc: abnormal termination of SMCD link groupsUrsula Braun
A final cleanup due to SMCD device removal means immediate freeing of all link groups belonging to this device in interrupt context. This patch introduces a separate SMCD link group termination routine, which terminates all link groups of an SMCD device. This new routine smcd_terminate_all ()is reused if the smc module is unloaded. 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>
2019-10-22net/smc: cancel send and receive for terminated socketUrsula Braun
The resources for a terminated socket are being cleaned up. This patch makes sure * no more data is received for an actively terminated socket * no more data is sent for an actively or passively terminated socket Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-08-20net/smc: make sure EPOLLOUT is raisedJason Baron
Currently, we are only explicitly setting SOCK_NOSPACE on a write timeout for non-blocking sockets. Epoll() edge-trigger mode relies on SOCK_NOSPACE being set when -EAGAIN is returned to ensure that EPOLLOUT is raised. Expand the setting of SOCK_NOSPACE to non-blocking sockets as well that can use SO_SNDTIMEO to adjust their write timeout. This mirrors the behavior that Eric Dumazet introduced for tcp sockets. Signed-off-by: Jason Baron <jbaron@akamai.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Ursula Braun <ubraun@linux.ibm.com> Cc: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-21net/smc: cleanup for smcr_tx_sndbuf_nonemptyUrsula Braun
Use local variable pflags from the beginning of function smcr_tx_sndbuf_nonempty Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-12net/smc: no delay for free tx buffer waitKarsten Graul
When no free transfer buffers are available then a work to call smc_tx_work() is scheduled. Set the schedule delay to zero, because for the out-of-buffers condition the work can start immediately and will block in the called function smc_wr_tx_get_free_slot(), waiting for free buffers. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-12net/smc: move wake up of close waiterKarsten Graul
Move the call to smc_close_wake_tx_prepared() (which wakes up a possibly waiting close processing that might wait for 'all data sent') to smc_tx_sndbuf_nonempty() (which is the main function to send data). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-12net/smc: reset cursor update required flagKarsten Graul
When an updated rx_cursor_confirmed field was sent to the peer then reset the cons_curs_upd_req flag. And remove the duplicate reset and cursor update in smc_tx_consumer_update(). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-04net/smc: fix sender_free computationUrsula Braun
In some scenarios a separate consumer cursor update is necessary. The decision is made in smc_tx_consumer_cursor_update(). The sender_free computation could be wrong: The rx confirmed cursor is always smaller than or equal to the rx producer cursor. The parameters in the smc_curs_diff() call have to be exchanged, otherwise sender_free might even be negative. And if more data arrives local_rx_ctrl.prod might be updated, enabling a cursor difference between local_rx_ctrl.prod and rx confirmed cursor larger than the RMB size. This case is not covered by smc_curs_diff(). Thus function smc_curs_diff_large() is introduced here. If a recvmsg() is processed in parallel, local_tx_ctrl.cons might change during smc_cdc_msg_send. Make sure rx_curs_confirmed is updated with the actually sent local_tx_ctrl.cons value. Fixes: e82f2e31f559 ("net/smc: optimize consumer cursor updates") Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-04net/smc: preallocated memory for rdma work requestsUrsula Braun
The work requests for rdma writes are built in local variables within function smc_tx_rdma_write(). This violates the rule that the work request storage has to stay till the work request is confirmed by a completion queue response. This patch introduces preallocated memory for these work requests. The storage is allocated, once a link (and thus a queue pair) is established. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-01net/smc: do not wait under send_lockKarsten Graul
smc_cdc_get_free_slot() might wait for free transfer buffers when using SMC-R. This wait should not be done under the send_lock, which is a spin_lock. This fixes a cpu loop in parallel threads waiting for the send_lock. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-01net/smc: don't wait for send buffer space when data was already sentKarsten Graul
When there is no more send buffer space and at least 1 byte was already sent then return to user space. The wait is only done when no data was sent by the sendmsg() call. This fixes smc_tx_sendmsg() which tried to always send all user data and started to wait for free send buffer space when needed. During this wait the user space program was blocked in the sendmsg() call and hence not able to receive incoming data. When both sides were in such a situation then the connection stalled forever. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-16Merge branch 'linus/master' into rdma.git for-nextJason Gunthorpe
rdma.git merge resolution for the 4.19 merge window Conflicts: drivers/infiniband/core/rdma_core.c - Use the rdma code and revise with the new spelling for atomic_fetch_add_unless drivers/nvme/host/rdma.c - Replace max_sge with max_send_sge in new blk code drivers/nvme/target/rdma.c - Use the blk code and revise to use NULL for ib_post_recv when appropriate - Replace max_sge with max_recv_sge in new blk code net/rds/ib_send.c - Use the net code and revise to use NULL for ib_post_recv when appropriate Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-16Merge tag 'v4.18' into rdma.git for-nextJason Gunthorpe
Resolve merge conflicts from the -rc cycle against the rdma.git tree: Conflicts: drivers/infiniband/core/uverbs_cmd.c - New ifs added to ib_uverbs_ex_create_flow in -rc and for-next - Merge removal of file->ucontext in for-next with new code in -rc drivers/infiniband/core/uverbs_main.c - for-next removed code from ib_uverbs_write() that was modified in for-rc Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-24net/smc: Simplify ib_post_(send|recv|srq_recv)() callsBart Van Assche
Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL as third argument to ib_post_(send|recv|srq_recv)(). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Acked-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-23net/smc: eliminate cursor read and write callsStefan Raspl
The functions to read and write cursors are exclusively used to copy cursors. Therefore switch to a respective function instead. Signed-off-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-18net/smc: optimize consumer cursor updatesUrsula Braun
The SMC protocol requires to send a separate consumer cursor update, if it cannot be piggybacked to updates of the producer cursor. Currently the decision to send a separate consumer cursor update just considers the amount of data already received by the socket program. It does not consider the amount of data already arrived, but not yet consumed by the receiver. Basing the decision on the difference between already confirmed and already arrived data (instead of difference between already confirmed and already consumed data), may lead to a somewhat earlier consumer cursor update send in fast unidirectional traffic scenarios, and thus to better throughput. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Suggested-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-30net/smc: add SMC-D support in data transferHans Wippel
The data transfer and CDC message headers differ in SMC-R and SMC-D. This patch adds support for the SMC-D data transfer to the existing SMC code. It consists of the following: * SMC-D CDC support * SMC-D tx support * SMC-D rx support The CDC header is stored at the beginning of the receive buffer. Thus, a rx_offset variable is added for the CDC header offset within the buffer (0 for SMC-R). Signed-off-by: Hans Wippel <hwippel@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Suggested-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-30net/smc: optimize consumer cursor updatesUrsula Braun
The SMC protocol requires to send a separate consumer cursor update, if it cannot be piggybacked to updates of the producer cursor. Currently the decision to send a separate consumer cursor update just considers the amount of data already received by the socket program. It does not consider the amount of data already arrived, but not yet consumed by the receiver. Basing the decision on the difference between already confirmed and already arrived data (instead of difference between already confirmed and already consumed data), may lead to a somewhat earlier consumer cursor update send in fast unidirectional traffic scenarios, and thus to better throughput. Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Suggested-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-23net/smc: urgent data supportStefan Raspl
Add support for out of band data send and receive. Signed-off-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18net/smc: calculate write offset in RMB only once per connectionHans Wippel
Currently, the write offset within the RMB is calculated on each write operation although it is fixed for each connection. With this patch, the offset is calculated once and stored in a connection specific variable. Signed-off-by: Hans Wippel <hwippel@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18net/smc: rename connection index to RMBE indexHans Wippel
The connection index is actually a RMBE index. So, this patch changes the name accordingly. Signed-off-by: Hans Wippel <hwippel@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-18net/smc: add common buffer size in send and receive buffer descriptorsHans Wippel
In addition to the buffer references, SMC currently stores the sizes of the receive and send buffers in each connection as separate variables. This patch introduces a buffer length variable in the common buffer descriptor and uses this length instead. Signed-off-by: Hans Wippel <hwippel@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
generated by cgit (git 2.34.1) at 2024-05-27 15:25:12 +0000