Messages in this thread | | | Date | Mon, 25 Jun 2018 22:59:37 -0400 | From | Steven Rostedt <> | Subject | Re: INFO: rcu detected stall in vprintk_emit |
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On Tue, 26 Jun 2018 10:49:24 +0900 Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> wrote:
> 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
> > --- > > 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; > } > > ---
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