From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D8CBF3E499; Mon, 14 Oct 2024 02:24:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728872689; cv=none; b=qaBE6aYiSNLay6722ZxlpDgvQZ6IcOoV+bXOoHLFItCkrASFh98pKx0lFd1M2zWQxaulAzxojpy3EhgouX1b2rqNJN72Gg9LFOEekmNU/J8p1luLSf9DIxMOwjekM5Q0COTPb1cC+7hRc8IYH0G5PYcqZhNRR8d49jLw1RUTnn0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728872689; c=relaxed/simple; bh=g/DAxs5dzK8K8pQYu35Djg8/2ZKXMriYr9hwS4xw9Vs=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=HsMjipkMJo581PYpQIFrSz5H7Sz/m0CNqHIpWmxrVmSXNrxCferby20f0TVQcuAaQBDw1S3K/OJca6GoVEf/DorHto5u4ugmxmnYruXasUU7z3PG8OhhXZcHjTjQJzxLhHuB6o4dGf6VaDx4cRWD1I1o2lw9+ppGWxD1DPDlMBU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F7I0mxWQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="F7I0mxWQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09E2FC4CEC5; Mon, 14 Oct 2024 02:24:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728872689; bh=g/DAxs5dzK8K8pQYu35Djg8/2ZKXMriYr9hwS4xw9Vs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=F7I0mxWQPO1NP6XxnSt/xCKZYnNeFPA6xxE4/tB3rximKv7jSHckBLO32HWgeDW1I me3LSdMNsvwQldl+e4aweJnsQPwM65Z3tlnwb8cNmTdll0dSuHKF/Qby8AHHVlnKE1 mDVgavh/qmpFCL62tgOgVX7rN9F5gXWK55+lFBIUGf47xM55HfinL2wykDA+Z55v5q f81Z5B5FHT1n8TZHGRwMVple0PI+JW00fDHZ4fwU69U/PMmH4fJlXzR8aPj5KxO0eW l8giR7PCctCRmlN15j9UJXapFfXpBZ3jyobL2W38tLmm3IlG/0jK3GrT+NC/Fva9HK By/oti/sMYpAg== Date: Mon, 14 Oct 2024 11:24:43 +0900 From: Masami Hiramatsu (Google) To: Leo Yan Cc: Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/3] perf probe: Improve log for long event name failure Message-Id: <20241014112443.97b129e774d9f313dc32568e@kernel.org> In-Reply-To: <20241012204725.928794-4-leo.yan@arm.com> References: <20241012204725.928794-1-leo.yan@arm.com> <20241012204725.928794-4-leo.yan@arm.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 12 Oct 2024 21:47:25 +0100 Leo Yan wrote: > If a symbol name is longer than the maximum event length (64 bytes), the > perf tool reports error: > > # perf probe -x test_cpp_mangle --add "this_is_a_very_very_long_print_data_abcdefghijklmnopqrstuvwxyz(int)" > snprintf() failed: -7; the event name nbase='this_is_a_very_very_long_print_data_abcdefghijklmnopqrstuvwxyz(int)' is too long > Error: Failed to add events. > > An information is missed in the log that the symbol name and the event > name can be set separately. Especially, this is recommended for adding > probe for a long symbol. > > This commit refines the log for reminding event syntax. > > After: > > # perf probe -x test_cpp_mangle --add "this_is_a_very_very_long_print_data_abcdefghijklmnopqrstuvwxyz(int)" > snprintf() failed: -7; the event name 'this_is_a_very_very_long_print_data_abcdefghijklmnopqrstuvwxyz(int)' is too long > Hint: Set a shorter event with syntax "EVENT=PROBEDEF" > EVENT: Event name (max length: 64 bytes). > Error: Failed to add events. > Nice! Acked-by: Masami Hiramatsu (Google) Thank you, > Signed-off-by: Leo Yan > --- > tools/perf/util/probe-event.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index 224ec6818803..2a2fc5e78c5c 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -2760,7 +2760,10 @@ static int get_new_event_name(char *buf, size_t len, const char *base, > /* Try no suffix number */ > ret = e_snprintf(buf, len, "%s%s", nbase, ret_event ? "__return" : ""); > if (ret < 0) { > - pr_warning("snprintf() failed: %d; the event name nbase='%s' is too long\n", ret, nbase); > + pr_warning("snprintf() failed: %d; the event name '%s' is too long\n" > + " Hint: Set a shorter event with syntax \"EVENT=PROBEDEF\"\n" > + " EVENT: Event name (max length: %d bytes).\n", > + ret, nbase, MAX_EVENT_NAME_LEN); > goto out; > } > if (!strlist__has_entry(namelist, buf)) > @@ -2780,7 +2783,10 @@ static int get_new_event_name(char *buf, size_t len, const char *base, > for (i = 1; i < MAX_EVENT_INDEX; i++) { > ret = e_snprintf(buf, len, "%s_%d", nbase, i); > if (ret < 0) { > - pr_debug("snprintf() failed: %d\n", ret); > + pr_warning("Add suffix failed: %d; the event name '%s' is too long\n" > + " Hint: Set a shorter event with syntax \"EVENT=PROBEDEF\"\n" > + " EVENT: Event name (max length: %d bytes).\n", > + ret, nbase, MAX_EVENT_NAME_LEN); > goto out; > } > if (!strlist__has_entry(namelist, buf)) > -- > 2.25.1 > -- Masami Hiramatsu (Google)