From nobody Tue Dec 16 11:45:35 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1108C4167B for ; Thu, 7 Dec 2023 22:30:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231950AbjLGWaf (ORCPT ); Thu, 7 Dec 2023 17:30:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229634AbjLGWac (ORCPT ); Thu, 7 Dec 2023 17:30:32 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23D70BA for ; Thu, 7 Dec 2023 14:30:39 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24756C433C8; Thu, 7 Dec 2023 22:30:38 +0000 (UTC) Date: Thu, 7 Dec 2023 17:31:08 -0500 From: Steven Rostedt To: LKML , Linux Trace Kernel Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers Subject: [PATCH v2] ring-buffer: Add offset of events in dump on mismatch Message-ID: <20231207173108.484b912c@gandalf.local.home> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" On bugs that have the ring buffer timestamp get out of sync, the config CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS, that checks for it and if it is detected it causes a dump of the bad sub buffer. It shows each event and their timestamp as well as the delta in the event. But it's also good to see the offset into the subbuffer for that event to know if how close to the end it is. Signed-off-by: Steven Rostedt (Google) Acked-by: Masami Hiramatsu (Google) --- Changes since v1: https://lore.kernel.org/linux-trace-kernel/20231207171613= .0592087d@gandalf.local.home - Add "0x" before the "%x" to make the print less confusing (Mathieu Desnoy= ers) kernel/trace/ring_buffer.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 8d2a4f00eca9..09d4b1aa8820 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3424,23 +3424,27 @@ static void dump_buffer_page(struct buffer_data_pag= e *bpage, case RINGBUF_TYPE_TIME_EXTEND: delta =3D rb_event_time_stamp(event); ts +=3D delta; - pr_warn(" [%lld] delta:%lld TIME EXTEND\n", ts, delta); + pr_warn(" 0x%x: [%lld] delta:%lld TIME EXTEND\n", + e, ts, delta); break; =20 case RINGBUF_TYPE_TIME_STAMP: delta =3D rb_event_time_stamp(event); ts =3D rb_fix_abs_ts(delta, ts); - pr_warn(" [%lld] absolute:%lld TIME STAMP\n", ts, delta); + pr_warn(" 0x%x: [%lld] absolute:%lld TIME STAMP\n", + e, ts, delta); break; =20 case RINGBUF_TYPE_PADDING: ts +=3D event->time_delta; - pr_warn(" [%lld] delta:%d PADDING\n", ts, event->time_delta); + pr_warn(" 0x%x: [%lld] delta:%d PADDING\n", + e, ts, event->time_delta); break; =20 case RINGBUF_TYPE_DATA: ts +=3D event->time_delta; - pr_warn(" [%lld] delta:%d\n", ts, event->time_delta); + pr_warn(" 0x%x: [%lld] delta:%d\n", + e, ts, event->time_delta); break; =20 default: --=20 2.42.0