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path: root/net/smc/smc_wr.h
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2023-03-17net/smc: Use percpu ref for wr tx referenceKai Shen
The refcount wr_tx_refcnt may cause cache thrashing problems among cores and we can use percpu ref to mitigate this issue here. We gain some performance improvement with percpu ref here on our customized smc-r verion. Applying cache alignment may also mitigate this problem but it seem more reasonable to use percpu ref here. We can also replace wr_reg_refcnt with one percpu reference like wr_tx_refcnt. redis-benchmark on smc-r with atomic wr_tx_refcnt: SET: 525707.06 requests per second, p50=0.087 msec GET: 554877.38 requests per second, p50=0.087 msec redis-benchmark on the percpu_ref version: SET: 540482.06 requests per second, p50=0.087 msec GET: 570711.12 requests per second, p50=0.079 msec Cases are like "redis-benchmark -h x.x.x.x -q -t set,get -P 1 -n 5000000 -c 50 -d 10 --threads 4". Signed-off-by: Kai Shen <KaiShen@linux.alibaba.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-09-07net/smc: Fix possible access to freed memory in link clearYacan Liu
After modifying the QP to the Error state, all RX WR would be completed with WC in IB_WC_WR_FLUSH_ERR status. Current implementation does not wait for it is done, but destroy the QP and free the link group directly. So there is a risk that accessing the freed memory in tasklet context. Here is a crash example: BUG: unable to handle page fault for address: ffffffff8f220860 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD f7300e067 P4D f7300e067 PUD f7300f063 PMD 8c4e45063 PTE 800ffff08c9df060 Oops: 0002 [#1] SMP PTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: G S OE 5.10.0-0607+ #23 Hardware name: Inspur NF5280M4/YZMB-00689-101, BIOS 4.1.20 07/09/2018 RIP: 0010:native_queued_spin_lock_slowpath+0x176/0x1b0 Code: f3 90 48 8b 32 48 85 f6 74 f6 eb d5 c1 ee 12 83 e0 03 83 ee 01 48 c1 e0 05 48 63 f6 48 05 00 c8 02 00 48 03 04 f5 00 09 98 8e <48> 89 10 8b 42 08 85 c0 75 09 f3 90 8b 42 08 85 c0 74 f7 48 8b 32 RSP: 0018:ffffb3b6c001ebd8 EFLAGS: 00010086 RAX: ffffffff8f220860 RBX: 0000000000000246 RCX: 0000000000080000 RDX: ffff91db1f86c800 RSI: 000000000000173c RDI: ffff91db62bace00 RBP: ffff91db62bacc00 R08: 0000000000000000 R09: c00000010000028b R10: 0000000000055198 R11: ffffb3b6c001ea58 R12: ffff91db80e05010 R13: 000000000000000a R14: 0000000000000006 R15: 0000000000000040 FS: 0000000000000000(0000) GS:ffff91db1f840000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff8f220860 CR3: 00000001f9580004 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> _raw_spin_lock_irqsave+0x30/0x40 mlx5_ib_poll_cq+0x4c/0xc50 [mlx5_ib] smc_wr_rx_tasklet_fn+0x56/0xa0 [smc] tasklet_action_common.isra.21+0x66/0x100 __do_softirq+0xd5/0x29c asm_call_irq_on_stack+0x12/0x20 </IRQ> do_softirq_own_stack+0x37/0x40 irq_exit_rcu+0x9d/0xa0 sysvec_call_function_single+0x34/0x80 asm_sysvec_call_function_single+0x12/0x20 Fixes: bd4ad57718cc ("smc: initialize IB transport incl. PD, MR, QP, CQ, event, WR") Signed-off-by: Yacan Liu <liuyacan@corp.netease.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-15net/smc: Remove unused function declarationWen Gu
The declaration of smc_wr_tx_dismiss_slots() is unused. So remove it. Fixes: 349d43127dac ("net/smc: fix kernel panic caused by race of smc_sock") Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Reviewed-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-28net/smc: fix kernel panic caused by race of smc_sockDust Li
A crash occurs when smc_cdc_tx_handler() tries to access smc_sock but smc_release() has already freed it. [ 4570.695099] BUG: unable to handle page fault for address: 000000002eae9e88 [ 4570.696048] #PF: supervisor write access in kernel mode [ 4570.696728] #PF: error_code(0x0002) - not-present page [ 4570.697401] PGD 0 P4D 0 [ 4570.697716] Oops: 0002 [#1] PREEMPT SMP NOPTI [ 4570.698228] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-rc4+ #111 [ 4570.699013] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 8c24b4c 04/0 [ 4570.699933] RIP: 0010:_raw_spin_lock+0x1a/0x30 <...> [ 4570.711446] Call Trace: [ 4570.711746] <IRQ> [ 4570.711992] smc_cdc_tx_handler+0x41/0xc0 [ 4570.712470] smc_wr_tx_tasklet_fn+0x213/0x560 [ 4570.712981] ? smc_cdc_tx_dismisser+0x10/0x10 [ 4570.713489] tasklet_action_common.isra.17+0x66/0x140 [ 4570.714083] __do_softirq+0x123/0x2f4 [ 4570.714521] irq_exit_rcu+0xc4/0xf0 [ 4570.714934] common_interrupt+0xba/0xe0 Though smc_cdc_tx_handler() checked the existence of smc connection, smc_release() may have already dismissed and released the smc socket before smc_cdc_tx_handler() further visits it. smc_cdc_tx_handler() |smc_release() if (!conn) | | |smc_cdc_tx_dismiss_slots() | smc_cdc_tx_dismisser() | |sock_put(&smc->sk) <- last sock_put, | smc_sock freed bh_lock_sock(&smc->sk) (panic) | To make sure we won't receive any CDC messages after we free the smc_sock, add a refcount on the smc_connection for inflight CDC message(posted to the QP but haven't received related CQE), and don't release the smc_connection until all the inflight CDC messages haven been done, for both success or failed ones. Using refcount on CDC messages brings another problem: when the link is going to be destroyed, smcr_link_clear() will reset the QP, which then remove all the pending CQEs related to the QP in the CQ. To make sure all the CQEs will always come back so the refcount on the smc_connection can always reach 0, smc_ib_modify_qp_reset() was replaced by smc_ib_modify_qp_error(). And remove the timeout in smc_wr_tx_wait_no_pending_sends() since we need to wait for all pending WQEs done, or we may encounter use-after- free when handling CQEs. For IB device removal routine, we need to wait for all the QPs on that device been destroyed before we can destroy CQs on the device, or the refcount on smc_connection won't reach 0 and smc_sock cannot be released. Fixes: 5f08318f617b ("smc: connection data control (CDC)") Reported-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-28net/smc: don't send CDC/LLC message if link not readyDust Li
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: 5f08318f617b ("smc: connection data control (CDC)") Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-16net/smc: extend LLC layer for SMC-Rv2Karsten Graul
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>
2021-10-16net/smc: add v2 support to the work request layerKarsten Graul
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>
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>
2020-05-04net/smc: wait for departure of an IB messageKarsten Graul
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>
2020-05-03net/smc: delete an asymmetric link as SMC serverKarsten Graul
When a link group moved from asymmetric to symmetric state then the dangling asymmetric link can be deleted. Add smc_llc_find_asym_link() to find the respective link and add smc_llc_delete_asym_link() to delete it. 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>
2019-11-15net/smc: no WR buffer wait for terminating link groupUrsula Braun
Avoid waiting for a free work request buffer, if the link group is already terminating. 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>
2019-02-04net/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>
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>
2018-03-14net/smc: pay attention to MAX_ORDER for CQ entriesUrsula Braun
smc allocates a certain number of CQ entries for used RoCE devices. For mlx5 devices the chosen constant number results in a large allocation causing this warning: [13355.124656] WARNING: CPU: 3 PID: 16535 at mm/page_alloc.c:3883 __alloc_pages_nodemask+0x2be/0x10c0 [13355.124657] Modules linked in: smc_diag(O) smc(O) xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc ip6table_filter ip6_tables iptable_filter mlx5_ib ib_core sunrpc mlx5_core s390_trng rng_core ghash_s390 prng aes_s390 des_s390 des_generic sha512_s390 sha256_s390 sha1_s390 sha_common ptp pps_core eadm_sch dm_multipath dm_mod vhost_net tun vhost tap sch_fq_codel kvm ip_tables x_tables autofs4 [last unloaded: smc] [13355.124672] CPU: 3 PID: 16535 Comm: kworker/3:0 Tainted: G O 4.14.0uschi #1 [13355.124673] Hardware name: IBM 3906 M04 704 (LPAR) [13355.124675] Workqueue: events smc_listen_work [smc] [13355.124677] task: 00000000e2f22100 task.stack: 0000000084720000 [13355.124678] Krnl PSW : 0704c00180000000 000000000029da76 (__alloc_pages_nodemask+0x2be/0x10c0) [13355.124681] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 [13355.124682] Krnl GPRS: 0000000000000000 00550e00014080c0 0000000000000000 0000000000000001 [13355.124684] 000000000029d8b6 00000000f3bfd710 0000000000000000 00000000014080c0 [13355.124685] 0000000000000009 00000000ec277a00 0000000000200000 0000000000000000 [13355.124686] 0000000000000000 00000000000001ff 000000000029d8b6 0000000084723720 [13355.124708] Krnl Code: 000000000029da6a: a7110200 tmll %r1,512 000000000029da6e: a774ff29 brc 7,29d8c0 #000000000029da72: a7f40001 brc 15,29da74 >000000000029da76: a7f4ff25 brc 15,29d8c0 000000000029da7a: a7380000 lhi %r3,0 000000000029da7e: a7f4fef1 brc 15,29d860 000000000029da82: 5820f0c4 l %r2,196(%r15) 000000000029da86: a53e0048 llilh %r3,72 [13355.124720] Call Trace: [13355.124722] ([<000000000029d8b6>] __alloc_pages_nodemask+0xfe/0x10c0) [13355.124724] [<000000000013bd1e>] s390_dma_alloc+0x6e/0x148 [13355.124733] [<000003ff802eeba6>] mlx5_dma_zalloc_coherent_node+0x8e/0xe0 [mlx5_core] [13355.124740] [<000003ff802eee18>] mlx5_buf_alloc_node+0x70/0x108 [mlx5_core] [13355.124744] [<000003ff804eb410>] mlx5_ib_create_cq+0x558/0x898 [mlx5_ib] [13355.124749] [<000003ff80407d40>] ib_create_cq+0x48/0x88 [ib_core] [13355.124751] [<000003ff80109fba>] smc_ib_setup_per_ibdev+0x52/0x118 [smc] [13355.124753] [<000003ff8010bcb6>] smc_conn_create+0x65e/0x728 [smc] [13355.124755] [<000003ff801081a2>] smc_listen_work+0x2d2/0x540 [smc] [13355.124756] [<0000000000162c66>] process_one_work+0x1be/0x440 [13355.124758] [<0000000000162f40>] worker_thread+0x58/0x458 [13355.124759] [<0000000000169e7e>] kthread+0x14e/0x168 [13355.124760] [<00000000009ce8be>] kernel_thread_starter+0x6/0xc [13355.124762] [<00000000009ce8b8>] kernel_thread_starter+0x0/0xc [13355.124762] Last Breaking-Event-Address: [13355.124764] [<000000000029da72>] __alloc_pages_nodemask+0x2ba/0x10c0 [13355.124764] ---[ end trace 34be38b581c0b585 ]--- This patch reduces the smc constant for the maximum number of allocated completion queue entries SMC_MAX_CQE by 2 to avoid high round up values in the mlx5 code, and reduces the number of allocated completion queue entries even more, if the final allocation for an mlx5 device hits the MAX_ORDER limit. Reported-by: Ihnken Menssen <menssen@de.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24net/smc: get rid of tx_pend waits in socket closingUrsula Braun
There is no need to wait for confirmation of pending tx requests for a closing connection, since pending tx slots are dismissed when finishing a connection. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-29net/smc: register RMB-related memory regionUrsula Braun
A memory region created for a new RMB must be registered explicitly, before the peer can make use of it for remote DMA transfer. Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09smc: socket closing and linkgroup cleanupUrsula Braun
smc_shutdown() and smc_release() handling delayed linkgroup cleanup for linkgroups without connections Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09smc: connection data control (CDC)Ursula Braun
send and receive CDC messages (via IB message send and CQE) Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09smc: work request (WR) base for use by LLC and CDCUrsula Braun
The base containers for RDMA transport are work requests and completion queue entries processed through Infiniband verbs: * allocate and initialize these areas * map these areas to DMA * implement the basic communication consisting of work request posting and receival of completion queue events Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>