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 EB6564C97 for ; Thu, 19 Feb 2026 18:49:40 +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=1771526981; cv=none; b=tE3qY3G9xJlK4Wo59ppjoZEQj/VFjHIm1P7wRy46w1BWBZvxNviG/iL1yM+X/f40W0wy082hMdjG1/2t+AP0I89fJ63A0vtXx/ASHIkPZwOOB98B0RXCNcLnIqM0ScX/aKvGJI6TDgTwxHrYd+kLTcL8Ld6hthcLWElJh+Tm524= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771526981; c=relaxed/simple; bh=TxLZlco3WzLCh6ZK6cpMEeEUEimMKgvayVIJg4XDFvQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NLz10tyGE+Gu/Wa1Hzw/25UAgCDeiuW6nh3LKNy+d5omJdYs8Dg5gxdvyJ7Cyiss0HpUmDa/oZ90p0OGikrMxd0QU1oQXcb63IZMVGKAQmRJiM2X9RL47ffGKQ7HtwbWDkAsG8v/3eKhCaZnNGauY6/ypcglxdG6DBpn8YFpU/w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qghs2idW; 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="qghs2idW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C103C4CEF7; Thu, 19 Feb 2026 18:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771526980; bh=TxLZlco3WzLCh6ZK6cpMEeEUEimMKgvayVIJg4XDFvQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qghs2idW4WeHgv6TcjcSPEOyFCqqVb6PH1QQtnuxyjX/yqoE6uutFJ+0qwWwbSNfs EkLzuaLZIlxaereXWgIsxWQZbr+T2v+x3jY/MlsJkItEkm0GH/+6DIwM6SIhTS45lX 8OQrjzgYq3f+aBuB0Eb2MEpj74wAfJmRQ8NAyYzRVg3he94nBkYby+PNMvqrDz5LX1 LAWRgiMeL8N6ZmkEWwA7dxM9ERYtompQ8F0JNLMTZgXsVEMYPJqgCYi+TPVnYkTS0g GyULxLuMrlRcVxJSlLTDc6zc6SnukQhi15AyIXm07F110JnSNHHjhU1Iisqc4kh7EP 5BQQX/fWoHQgg== Date: Thu, 19 Feb 2026 10:49:37 -0800 From: Namhyung Kim To: Arnaldo Melo Cc: David Ahern , Arnaldo Carvalho de Melo , LKML , Jiri Olsa Subject: Re: perf-trace: improving ioctl details Message-ID: References: <4babff5e-5a27-4e3b-b9c6-16fd2781af35@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 In-Reply-To: Hi David! On Wed, Feb 18, 2026 at 04:34:33PM -0300, Arnaldo Melo wrote: > > > On February 18, 2026 2:09:26 PM GMT-03:00, David Ahern wrote: > >Hi Arnaldo, Namhyung: > > > >I have a couple of patches to perf-trace to improve the details on ioctl > >calls. The first one tracks stats by individual filenames, and for the > >summary output prints the ioctl stats per filename. > > > > Looks interesting! Indeed. > > > >The second patch improves the output for the _IOC_NR element of the op > >argument. For flexibility across kernel versions and drivers, it adds > >the ability to read input files that contain the conversion from number > >to human readable name. The files (if the option is set) are parsed at > >start up. In addition to the summary, the cache is also used to improve > >the readability of each ioctl line. > > > >Questions for you: > >1. is such an open ended design acceptable for perf-trace? > > Is it lazy, i.e. only when needed this cache/table gets loaded? I think it's ok. But I'm curious what's the actual usecases.. do you want it for testing kernels and drivers? I guess we can have a default table for regular users and provide the option for kernel developers. > > > > >2. if yes, is there any preference on file format (json, yaml, > >key-value, ...)? > > We already have JSON parsing infra, so probably that is better? JSON should be fine, although it's a bit verbose. I'm fine with plain KEY=VALUE format too if it's really a simple mapping. > > Great to see you contributing to perf again! +1 Thanks, Namhyung