From nobody Fri Dec 19 00:36:43 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 64217C4332F for ; Wed, 13 Dec 2023 02:19:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378333AbjLMCTl (ORCPT ); Tue, 12 Dec 2023 21:19:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378308AbjLMCTW (ORCPT ); Tue, 12 Dec 2023 21:19:22 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 550C0BC for ; Tue, 12 Dec 2023 18:19:28 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 46190C433A9; Wed, 13 Dec 2023 02:19:27 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rDEr5-00000002Tpn-0JKL; Tue, 12 Dec 2023 21:20:11 -0500 Message-ID: <20231213022010.851142884@goodmis.org> User-Agent: quilt/0.67 Date: Tue, 12 Dec 2023 21:19:24 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Tzvetomir Stoyanov , Vincent Donnefort , Kent Overstreet Subject: [PATCH v2 10/15] tracing: Stop the tracing while changing the ring buffer subbuf size References: <20231213021914.361709558@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 7c5ef3f33d81..0cb5e1a50e65 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9405,13 +9405,16 @@ 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 @@ -9438,11 +9441,15 @@ 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