From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 1E2C4214A78 for ; Thu, 9 Jan 2025 07:53:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736409192; cv=none; b=DIDtpxe6PutacNdLJRdGn7m0LtQo6XWqGKzJVGe4oFIclvY4ArfoIRYiKVnrJroNAomZQFA0QKN7vi8JAjyWdi7IJkmaTVLQHXR7DKzHAQLm0lDYEgbA5+ZlUN2vfYxDDnI9TUYCBWeTZ+Y1QSu5xMlhXILitsq8HLS82Ar1TsA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736409192; c=relaxed/simple; bh=GKA/s0dhS3y5Q0wClnwz/vinA1zILLOoLzSvzMb3AiA=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=fluk/vDexkl/vGGfWruZKzcxMsbBF1w51YIYfSdvvZfgFQN5+baGiXs7rQbWReg8CbRoWY1LoQSZ7mcC8wm6xKDddSNV4YjwP/Vi+srMeWrqyYfgh2Ep+LJ3Fjzxc3T2hr+yegsfSTEUNWy3MPQn9vgaB0QIjNY4FUwK56XHdMY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=ZmWc2eGH; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ZmWc2eGH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1736409189; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=gfO+r5xR4PUDrsRJu5n76LpjO4EViTJFVCpyoVSyyzU=; b=ZmWc2eGHgxH3osGY6b553wU9MaSz+DnsDjJchQYhO7egM3yUhOxF8LhH04qvXd6EN+p8Gx BM7jRoOC03Pp0mf9s1QhXBE/eM3N28O13quwIIumi2I9Pjv34sro2agUAgmY+SdnV0zU8v yvOcYSJYy57lmc8951WGzSyNTUtV4u8= Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-208-TVBcF4XQOKKUY_mGj9bjyg-1; Thu, 09 Jan 2025 02:53:07 -0500 X-MC-Unique: TVBcF4XQOKKUY_mGj9bjyg-1 X-Mimecast-MFC-AGG-ID: TVBcF4XQOKKUY_mGj9bjyg Received: by mail-qk1-f199.google.com with SMTP id af79cd13be357-7b6e5c9ef38so99782885a.1 for ; Wed, 08 Jan 2025 23:53:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736409187; x=1737013987; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=gfO+r5xR4PUDrsRJu5n76LpjO4EViTJFVCpyoVSyyzU=; b=dkoo28mps1zhmwLk1Nc6aTpGvDdLQe/WZWWIgFfp4PqVY0TSkKh5bJG3+cEWpVxkZ9 3rBPkEnsnJHyMEpxU0vBW1W4y0Ee+qKYg7A2kGVsJJQHaWmmkop/OaZaW1Nrr9eBdL7S 7R6UYyXrHaGHOsZUPs6bqhOk68bwGg00BF6HbaNSrwAhHPlVaF7GYmZAStxwmzDBMFqu ts0TjU0J1/p1my+cZLzCyJIMLWX2fB3nH8U169VABRzZBKo7rcOO8Ibt/FlyZGEEhs5d WGi5rb/NO4Vgs+L2dQ8bTo/Z+bChmnFv8IFlzk/7GtfG+yK35N0Ja7V6Vf09fvT/Y+j7 q07w== X-Forwarded-Encrypted: i=1; AJvYcCXH+YSIKh/m0eKXMOqNZKr/S+J1wNkpVSVtOnf5Hc1Lw7NCZhvXBp65myu75Tu3+VbVrSa8J80DRkzuAz8=@vger.kernel.org X-Gm-Message-State: AOJu0YyvS+J3V0rGbyQtGfY4JINHht81Ta35616ydGL7VOQ0evU5EY2h 7nVG+Q7qTuRu+PiTWC7mwPcws/vZn5qGOFcqBiHYYRCatJYI/Rgh/13ThQ5VDjX5Clt1e+2+2X+ lj3OCS9h59X5UQL3MJ6oRQZiKJUNHgwt0CA8fyeTunyM42sdJB+PBYTYXd5S+nPtokvUC0pYP X-Gm-Gg: ASbGnctrG7zGaSSSBhgBFcmWCN/Ra3i0l4G35m/ODetYaVA6PQsIfqg59ETtMrSLfst 5cp0Rm+QdSQiNj9GycZMCLpWJdHdAPXGmCpQFZWnehVFRB1wFzrbE9SDD3TD+tWKYIxdL9fDFMq fcxCWBLQTwevynlM/XdlqnScaNhiCcbrUIpWsOVDKM6Q8sJ8SCgorsauufCWWNgM4516KY5Bojh xqHONZ4lWa97gMqbBWQbO7eF7xmxMHVz6Ngjz2NWdtZyf+GRVp75dErPC89X3N0Zr1APDweDAod 3lRM+YA= X-Received: by 2002:a05:620a:248d:b0:7a9:abdf:f517 with SMTP id af79cd13be357-7bce1286ea9mr359755185a.25.1736409187072; Wed, 08 Jan 2025 23:53:07 -0800 (PST) X-Google-Smtp-Source: AGHT+IEEEiUGlJ10Kc8Mh22kcaQUJV1JNv8LIMdR5nsQVb0+EmtKA1fprNXE6lw3tD9o0QflpgqiqA== X-Received: by 2002:a05:620a:248d:b0:7a9:abdf:f517 with SMTP id af79cd13be357-7bce1286ea9mr359753885a.25.1736409186814; Wed, 08 Jan 2025 23:53:06 -0800 (PST) Received: from gmonaco-thinkpadt14gen3.rmtit.csb ([185.107.56.30]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7bce3248514sm42623685a.28.2025.01.08.23.53.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Jan 2025 23:53:06 -0800 (PST) Message-ID: Subject: Re: [PATCH 1/2] perf ftrace: Check min/max latency only with bucket range From: Gabriele Monaco To: Namhyung Kim , Arnaldo Carvalho de Melo , Ian Rogers , Kan Liang Cc: Jiri Olsa , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org Date: Thu, 09 Jan 2025 08:53:02 +0100 In-Reply-To: <20250108210015.1188531-1-namhyung@kernel.org> References: <20250108210015.1188531-1-namhyung@kernel.org> Autocrypt: addr=gmonaco@redhat.com; prefer-encrypt=mutual; keydata=mDMEZuK5YxYJKwYBBAHaRw8BAQdAmJ3dM9Sz6/Hodu33Qrf8QH2bNeNbOikqYtxWFLVm0 1a0JEdhYnJpZWxlIE1vbmFjbyA8Z21vbmFjb0ByZWRoYXQuY29tPoiZBBMWCgBBFiEEysoR+AuB3R Zwp6j270psSVh4TfIFAmbiuWMCGwMFCQWjmoAFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcCF4AACgk Q70psSVh4TfJzZgD/TXjnqCyqaZH/Y2w+YVbvm93WX2eqBqiVZ6VEjTuGNs8A/iPrKbzdWC7AicnK xyhmqeUWOzFx5P43S1E1dhsrLWgP Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.2 (3.54.2-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2025-01-08 at 13:00 -0800, Namhyung Kim wrote: > It's an optional feature and remains 0 when bucket range is not > given. > And it makes the histogram goes to the last entry always because any > latency (num) is greater than or equal to 0. Thanks Namhyung for fixing this, something definitely slipped while testing.. I confirm your patches work well also when the bucket range is provided but= the min latency isn't. I'm wondering if it would be cleaner to propagate your changes (using min/max latency only if bucket_range is provided) also to make_histogram. That function currently works since we assume min_latency to be always 0, which is the case but probably not considering it altogether would look a bit better and prevent some headache in the future. --- tools/perf/builtin-ftrace.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 076c703e5c334..82d63d7af9d03 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -779,19 +779,16 @@ static void make_histogram(struct perf_ftrace *ftrace= , int buckets[], if (ftrace->use_nsec) num *=3D 1000; =20 - i =3D 0; - if (num < min_latency) - goto do_inc; - - num -=3D min_latency; - if (!ftrace->bucket_range) { i =3D log2(num); if (i < 0) i =3D 0; } else { - // Less than 1 unit (ms or ns), or, in the future, - // than the min latency desired. + i =3D 0; + if (num < min_latency) + goto do_inc; + + num -=3D min_latency; if (num > 0) // 1st entry: [ 1 unit .. bucket_range units ] i =3D num / ftrace->bucket_range + 1; if (num >=3D max_latency - min_latency) base-commit: 257ccfaf9fbef6f54eabf1a8f8a8efcc9036439b --=20 2.47.1