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 18A9A25CC62; Wed, 26 Feb 2025 22:20:19 +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=1740608420; cv=none; b=Sfelj9XUCg+PBc9IrQhGakvETuq0XOU0OAOGQVA2FhJeiHMJV/S6BeTPOu8Iz9odtPjj+lMG9APCLdXoGbmwaSHkdgg27HfX8YTu0ZHWECpWk8ZH6MNgLda1F+rgAiafEkSvtNT0X2n0iKKGot0OrrMuSgmgA99Q/bC9jABOGd4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740608420; c=relaxed/simple; bh=07qZhyJhISYX9/vYcEeK3yIoNGlDFfoBl+hGuICMjrU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Yk+Df6pyq7DbmsiscB6G6Tg1h03vzhBWcD9/DV5YKlSbOocv04aHwp1/601CJf5tGFLRcLjisTR51W4QmdzASM+par4lyoNoU93MbHAIleE1jK/yfS3RsBHBZWQpA3Vz8CGiRRt6Ps9gQE6FGQyvssV8nLVLYd7bO7iRfEESG0w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=l+Wjd9c4; 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="l+Wjd9c4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B654C4CED6; Wed, 26 Feb 2025 22:20:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740608419; bh=07qZhyJhISYX9/vYcEeK3yIoNGlDFfoBl+hGuICMjrU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=l+Wjd9c4BiW7MdyTWgmca97572+fy0U6HdAnAGyr2Z+yZkQQJHeX62OnuERZ5Esa6 eoniR6IvEgvy+PqwmvVV/Kl+0NP5ZQw7v3tCi9J2zRP9il6omYW4kT2JLStu/WGBJu R18h1QSnFRto3uSg4fzdVc+IZP9dWG7rq9HG7Aovu1z6xFNC+gu65sgNuZ8GmmV/nB Ig97sN5CMs+3DqmGfD7uzQabu1v2FVbEWWFSOEdHMKWwwycAoa9+2x/P8p1nKFf/Y8 mgDulYmPPW+Cq7pBzQXsZfySR/U6p5mZPyQUuPQCumenUF4BmwU8pFO00/ZjtdrTg8 eBIJfCLH03+SA== Date: Wed, 26 Feb 2025 14:20:17 -0800 From: Namhyung Kim To: Song Liu Cc: Ian Rogers , Arnaldo Carvalho de Melo , Kan Liang , Jiri Olsa , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, James Clark Subject: Re: [PATCH] perf tools: Skip BPF sideband event for userspace profiling Message-ID: References: <20250226203039.1099131-1-namhyung@kernel.org> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Hello, On Wed, Feb 26, 2025 at 02:00:36PM -0800, Song Liu wrote: > On Wed, Feb 26, 2025 at 12:59 PM Ian Rogers wrote: > > > > On Wed, Feb 26, 2025 at 12:30 PM Namhyung Kim wrote: > > > > > > The BPF sideband information is tracked using a separate thread and > > > evlist. But it's only useful for profiling kernel and we can skip it > > > when users profile their application only. > > > > nit: It may be worth noting that profiling an application implicitly > > excludes the kernel samples. > > > > > It seems it already fails to open the sideband event in that case. > > > Let's remove the noise in the verbose output anyway. > > > > > > Cc: Song Liu > > > Signed-off-by: Namhyung Kim > > > > Reviewed-by: Ian Rogers Thanks for your review! > > > > I wonder if the second evlist could be avoided similar to Howard's > > off-CPU sample events? > > I also wonder if we should make the evlist responsible for BPF and > > dummy/sideband events. Having unnecessary events increases the list > > size iterated over when creating sideband data, and so has a runtime > > cost. Having the logic separated in places like builtin-top and > > builtin-record feels suboptimal. > > It appears we can indeed put this logic in evlist. Ok, I'll give it a spin. Thanks, Namhyung