Re: INFO: rcu detected stall in vprintk_emit
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2018-06-26 03:01:25
Also in:
linux-wireless, lkml
On Tue, 26 Jun 2018 10:49:24 +0900 Sergey Senozhatsky [off-list ref] wrote:
quoted hunk ↗ jump to hunk
So we can try switching to ratelimited error reporting [that would be option A]: ---diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c index 2ceefa183cee..2f3becb709b8 100644 --- a/net/nfc/llcp_commands.c +++ b/net/nfc/llcp_commands.c@@ -755,7 +755,7 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, frag_len + LLCP_HEADER_SIZE, &err); if (pdu == NULL) { - pr_err("Could not allocate PDU\n"); + pr_err_ratelimited("Could not allocate PDU\n"); continue; } ---Or ratelimited error reporting and cond_resched() [that would be option B]:
I don't think this is a printk() issue per se, so I think Option B is the only option. You should not get stuck in an infinite loop if we run short on memory. Perhaps we could have an Option C which would exit this loop gracefully with some kind of error. But I haven't looked at the surrounding code to be sure if that is possible. -- Steve
quoted hunk ↗ jump to hunk
---diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c index 2ceefa183cee..61741db4c4e6 100644 --- a/net/nfc/llcp_commands.c +++ b/net/nfc/llcp_commands.c@@ -755,7 +755,8 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, frag_len + LLCP_HEADER_SIZE, &err); if (pdu == NULL) { - pr_err("Could not allocate PDU\n"); + pr_err_ratelimited("Could not allocate PDU\n"); + cond_resched(); continue; }---