From mboxrd@z Thu Jan 1 00:00:00 1970 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 A9EF7C77B7A for ; Fri, 2 Jun 2023 11:18:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235813AbjFBLSq (ORCPT ); Fri, 2 Jun 2023 07:18:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235358AbjFBLSh (ORCPT ); Fri, 2 Jun 2023 07:18:37 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC264180 for ; Fri, 2 Jun 2023 04:17:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685704672; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=imQ8hkrYLqR8ckCqlA+Lim20RdkOae7FAIksRB3MKCQ=; b=LszkSpSo/Il7d347hmFA50w05ihPTUJdjDY8TPzvpQjkp+8H6OlijTvZiIMM6qnDtdiyf+ hATsmthYiynHwF+b1caiICQP7W5fXjtKwH+fF/zVOYteiOsx8fO4Yn3O87w8BtIQVNemAO Nx/PQ0KrmgmlR7zOcudOjdY+98y5pQg= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-7-AxRKHyJtMFaKTgKggW_8_A-1; Fri, 02 Jun 2023 07:15:31 -0400 X-MC-Unique: AxRKHyJtMFaKTgKggW_8_A-1 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-3f71907c036so10851835e9.3 for ; Fri, 02 Jun 2023 04:15:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685704531; x=1688296531; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=imQ8hkrYLqR8ckCqlA+Lim20RdkOae7FAIksRB3MKCQ=; b=TftNl7FbBPUTMi5MSl1e0gyBe0v6o+Rj0918W0Lt0lHzmZxiqzPWv4AElTcs5Qi0uf nkOVKVyl2oiSrd/p32sTomkhAhFodnLHUHwL/UhpJfaMZyaIOacjeTdiKAOHuQ7njrnH 5Ee1Bs60vlPiBFguZx7mb4PgYCmqwV7RqZyHs1gnIPbGeq+GpY5C2NZIBiHDCGugOTQG UFgOa2AgqkTq6J7yRS333O8RXpkFNJDKgIzh9N7WHAZ9i9kxc6Ec1OpqAp5tVufiCuqT nPgdo8h4/pPdMolJbTe4EVRQtbmnB5/duHVta5UsJhF1W3LXG3yCdwR1q/3azPRuBTrC kA0A== X-Gm-Message-State: AC+VfDwQLoaMht9BPuA/tsjIrM7KwPXJRxyWY8GPxZqfpSpf5yZ4E52X GNXjMQbG96V56OFPSsaKej5mKr7ZgcYgrwas/XWiB8vpm4NekwI1WHE3nRBDPD97G9Po/hnnout ZeOzPdT/Wfdk1pAi0PS5/R/wU X-Received: by 2002:a7b:c841:0:b0:3f7:26f8:f9c3 with SMTP id c1-20020a7bc841000000b003f726f8f9c3mr1064700wml.5.1685704530892; Fri, 02 Jun 2023 04:15:30 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ6UWcaTAnKc4xQxzU4UjZxKiFiySGLh197x+LFMig+w4H4npT0uQes1m4bOREHyF9AKJ4OAiw== X-Received: by 2002:a7b:c841:0:b0:3f7:26f8:f9c3 with SMTP id c1-20020a7bc841000000b003f726f8f9c3mr1064685wml.5.1685704530633; Fri, 02 Jun 2023 04:15:30 -0700 (PDT) Received: from redhat.com ([2.55.4.169]) by smtp.gmail.com with ESMTPSA id w11-20020a1cf60b000000b003f423f5b659sm1630095wmc.10.2023.06.02.04.15.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Jun 2023 04:15:29 -0700 (PDT) Date: Fri, 2 Jun 2023 07:15:26 -0400 From: "Michael S. Tsirkin" To: Ross Zwisler Cc: linux-kernel@vger.kernel.org, Ross Zwisler , Jason Wang , virtualization@lists.linux-foundation.org, linux-trace-kernel@vger.kernel.org, Steven Rostedt Subject: Re: [PATCH v2 5/6] tools/virtio: use canonical ftrace path Message-ID: <20230602071517-mutt-send-email-mst@kernel.org> References: <20230215223350.2658616-1-zwisler@google.com> <20230215223350.2658616-6-zwisler@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230215223350.2658616-6-zwisler@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 15, 2023 at 03:33:49PM -0700, Ross Zwisler wrote: > The canonical location for the tracefs filesystem is at /sys/kernel/tracing. > > But, from Documentation/trace/ftrace.rst: > > Before 4.1, all ftrace tracing control files were within the debugfs > file system, which is typically located at /sys/kernel/debug/tracing. > For backward compatibility, when mounting the debugfs file system, > the tracefs file system will be automatically mounted at: > > /sys/kernel/debug/tracing > > A few spots in tools/virtio still refer to this older debugfs > path, so let's update them to avoid confusion. > > Signed-off-by: Ross Zwisler queued this too. thanks! > --- > tools/virtio/virtio-trace/README | 2 +- > tools/virtio/virtio-trace/trace-agent.c | 12 ++++++++---- > 2 files changed, 9 insertions(+), 5 deletions(-) > > diff --git a/tools/virtio/virtio-trace/README b/tools/virtio/virtio-trace/README > index b64845b823ab..cea29a2a4c0a 100644 > --- a/tools/virtio/virtio-trace/README > +++ b/tools/virtio/virtio-trace/README > @@ -95,7 +95,7 @@ Run > > 1) Enable ftrace in the guest > > - # echo 1 > /sys/kernel/debug/tracing/events/sched/enable > + # echo 1 > /sys/kernel/tracing/events/sched/enable > > 2) Run trace agent in the guest > This agent must be operated as root. > diff --git a/tools/virtio/virtio-trace/trace-agent.c b/tools/virtio/virtio-trace/trace-agent.c > index cdfe77c2b4c8..7e2d9bbf0b84 100644 > --- a/tools/virtio/virtio-trace/trace-agent.c > +++ b/tools/virtio/virtio-trace/trace-agent.c > @@ -18,8 +18,9 @@ > #define PIPE_DEF_BUFS 16 > #define PIPE_MIN_SIZE (PAGE_SIZE*PIPE_DEF_BUFS) > #define PIPE_MAX_SIZE (1024*1024) > -#define READ_PATH_FMT \ > - "/sys/kernel/debug/tracing/per_cpu/cpu%d/trace_pipe_raw" > +#define TRACEFS "/sys/kernel/tracing" > +#define DEBUGFS "/sys/kernel/debug/tracing" > +#define READ_PATH_FMT "%s/per_cpu/cpu%d/trace_pipe_raw" > #define WRITE_PATH_FMT "/dev/virtio-ports/trace-path-cpu%d" > #define CTL_PATH "/dev/virtio-ports/agent-ctl-path" > > @@ -120,9 +121,12 @@ static const char *make_path(int cpu_num, bool this_is_write_path) > if (this_is_write_path) > /* write(output) path */ > ret = snprintf(buf, PATH_MAX, WRITE_PATH_FMT, cpu_num); > - else > + else { > /* read(input) path */ > - ret = snprintf(buf, PATH_MAX, READ_PATH_FMT, cpu_num); > + ret = snprintf(buf, PATH_MAX, READ_PATH_FMT, TRACEFS, cpu_num); > + if (ret > 0 && access(buf, F_OK) != 0) > + ret = snprintf(buf, PATH_MAX, READ_PATH_FMT, DEBUGFS, cpu_num); > + } > > if (ret <= 0) { > pr_err("Failed to generate %s path(CPU#%d):%d\n", > -- > 2.39.1.637.g21b0678d19-goog