From: Ye Bin <yebin10@xxxxxxxxxx> There's issue as follows: RPC: Registered rdma transport module. RPC: Registered rdma backchannel transport module. RPC: Unregistered rdma transport module. RPC: Unregistered rdma backchannel transport module. BUG: unable to handle page fault for address: fffffbfff80c609a PGD 123fee067 P4D 123fee067 PUD 123fea067 PMD 10c624067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI RIP: 0010:percpu_counter_destroy_many+0xf7/0x2a0 Call Trace: <TASK> __die+0x1f/0x70 page_fault_oops+0x2cd/0x860 spurious_kernel_fault+0x36/0x450 do_kern_addr_fault+0xca/0x100 exc_page_fault+0x128/0x150 asm_exc_page_fault+0x26/0x30 percpu_counter_destroy_many+0xf7/0x2a0 mmdrop+0x209/0x350 finish_task_switch.isra.0+0x481/0x840 schedule_tail+0xe/0xd0 ret_from_fork+0x23/0x80 ret_from_fork_asm+0x1a/0x30 </TASK> If register_sysctl() return NULL, then svc_rdma_proc_cleanup() will not destroy the percpu counters which init in svc_rdma_proc_init(). If CONFIG_HOTPLUG_CPU is enabled, residual nodes may be in the 'percpu_counters' list. The above issue may occur once the module is removed. If the CONFIG_HOTPLUG_CPU configuration is not enabled, memory leakage occurs. To solve above issue just destroy all percpu counters when register_sysctl() return NULL. Fixes: 1e7e55731628 ("svcrdma: Restore read and write stats") Fixes: 22df5a22462e ("svcrdma: Convert rdma_stat_sq_starve to a per-CPU counter") Fixes: df971cd853c0 ("svcrdma: Convert rdma_stat_recv to a per-CPU counter") Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx> --- net/sunrpc/xprtrdma/svc_rdma.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c index 58ae6ec4f25b..11dff4d58195 100644 --- a/net/sunrpc/xprtrdma/svc_rdma.c +++ b/net/sunrpc/xprtrdma/svc_rdma.c @@ -233,25 +233,33 @@ static int svc_rdma_proc_init(void) rc = percpu_counter_init(&svcrdma_stat_read, 0, GFP_KERNEL); if (rc) - goto out_err; + goto err; rc = percpu_counter_init(&svcrdma_stat_recv, 0, GFP_KERNEL); if (rc) - goto out_err; + goto err_read; rc = percpu_counter_init(&svcrdma_stat_sq_starve, 0, GFP_KERNEL); if (rc) - goto out_err; + goto err_recv; rc = percpu_counter_init(&svcrdma_stat_write, 0, GFP_KERNEL); if (rc) - goto out_err; + goto err_sq; svcrdma_table_header = register_sysctl("sunrpc/svc_rdma", svcrdma_parm_table); + if (!svcrdma_table_header) + goto err_write; + return 0; -out_err: +err_write: + percpu_counter_destroy(&svcrdma_stat_write); +err_sq: percpu_counter_destroy(&svcrdma_stat_sq_starve); +err_recv: percpu_counter_destroy(&svcrdma_stat_recv); +err_read: percpu_counter_destroy(&svcrdma_stat_read); +err: return rc; } -- 2.34.1