From nobody Sun Dec 28 02:40:25 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 A6A09C4332F for ; Wed, 13 Dec 2023 18:21:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442478AbjLMSV1 (ORCPT ); Wed, 13 Dec 2023 13:21:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235536AbjLMSUh (ORCPT ); Wed, 13 Dec 2023 13:20:37 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08691138 for ; Wed, 13 Dec 2023 10:20:39 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5F6CC43397; Wed, 13 Dec 2023 18:20:39 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rDTrJ-00000002aAn-0Hzz; Wed, 13 Dec 2023 13:21:25 -0500 Message-ID: <20231213182124.855007117@goodmis.org> User-Agent: quilt/0.67 Date: Wed, 13 Dec 2023 13:17:47 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Tzvetomir Stoyanov , Vincent Donnefort , Kent Overstreet Subject: [PATCH v3 10/15] tracing: Stop the tracing while changing the ring buffer subbuf size References: <20231213181737.791847466@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" Because the main buffer and the snapshot buffer need to be the same for some tracers, otherwise it will fail and disable all tracing, the tracers need to be stopped while updating the sub buffer sizes so that the tracers see the main and snapshot buffers with the same sub buffer size. Fixes: TBD ("ring-buffer: Add interface for configuring trace sub buffer si= ze") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 658bb1f04e9c..020350da99e3 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9406,13 +9406,16 @@ buffer_order_write(struct file *filp, const char __= user *ubuf, if (val < 0 || val > 7) return -EINVAL; =20 + /* Do not allow tracing while changing the order of the ring buffer */ + tracing_stop_tr(tr); + old_order =3D ring_buffer_subbuf_order_get(tr->array_buffer.buffer); if (old_order =3D=3D val) - return 0; + goto out; =20 ret =3D ring_buffer_subbuf_order_set(tr->array_buffer.buffer, val); if (ret) - return 0; + goto out; =20 #ifdef CONFIG_TRACER_MAX_TRACE =20 @@ -9439,11 +9442,15 @@ buffer_order_write(struct file *filp, const char __= user *ubuf, */ tracing_disabled =3D 1; } - return ret; + goto out; } out_max: #endif (*ppos)++; + out: + if (ret) + cnt =3D ret; + tracing_start_tr(tr); return cnt; } =20 --=20 2.42.0