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 E12FF18DF8F; Mon, 4 Nov 2024 21:00:39 +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=1730754040; cv=none; b=TAAyzR5xrGtbe/vBHz+ePUXmsK5IVZVBUXtmeZ5iZ9ALpfyyUbXxpd52Q7iAJwnpGSkjaJTH5v8v04U2auUkyJEOjf68x9dtgAAOnKueXJC52q7l5dILYq7Aixg7y+iqo820J+JOhe3fDKPlGzq/6djP1ulCnq1lsJPIb3/KwiU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730754040; c=relaxed/simple; bh=+JnuYJJgahecdEeb1aApIjChwSEPKJ0iG6ZTn0zz9I8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=t6g3DxnKuSWF4DFpnFFc2ZajItKQXUO7DO36vRIw0A/siF/wxt2i/AlzIAOiTcAuEVHA9ftplxKMrVYoH0zHPNKhe9RqkAqrmu+cUUiAQU++M2N4uBOS2l8FOV1RtMzYp0K0pgn4kXiEtKkHBWP3LR/cdk94gZJniu/7wVSzxFE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=r4mevY+T; 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="r4mevY+T" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC32FC4CECE; Mon, 4 Nov 2024 21:00:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730754039; bh=+JnuYJJgahecdEeb1aApIjChwSEPKJ0iG6ZTn0zz9I8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r4mevY+T/fi/gyAlN3rIuUjLExZmg5XdyI+cAIsOKBJ1e666rfkoBmxr69SAc0+ig 7GoOxfdVvLP8QdqEEqVnLCqwe/fcIrOhA5mkoZQglxGM21hB8m2Y9PjnbnI5EZKzjs k9Zs2wKR6dkmwsk1ztZhauP2+CcbzauVInTRpHUp63KDIdkoLuQkhaZVVMW/T60cnh Vmct/oj4YPADmwhn3QpgmGxJWL9RRVaCuGYSENM+NmlgZ7YtiRrRgbJuQRaluiAXPo CPvydklNv7mcStai/SUIVxWonF4eJyZj35FL8/EI5rkoXQ25tdyF4YhXXBxMv8o93z 9Czwh8U/AW7lw== Date: Mon, 4 Nov 2024 13:00:36 -0800 From: Namhyung Kim To: Ian Rogers Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Adrian Hunter , Kan Liang , James Clark , Howard Chu , Athira Jajeev , Michael Petlan , Veronika Molnarova , Dapeng Mi , Thomas Richter , Ilya Leoshkevich , Colin Ian King , Weilin Wang , Andi Kleen , Josh Poimboeuf , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: Re: [PATCH v5 06/21] perf script: Move find_scripts to browser/scripts.c Message-ID: References: <20241031014252.753588-1-irogers@google.com> <20241031014252.753588-7-irogers@google.com> Precedence: bulk X-Mailing-List: linux-perf-users@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: On Mon, Nov 04, 2024 at 12:48:01PM -0800, Ian Rogers wrote: > On Mon, Nov 4, 2024 at 12:39 PM Arnaldo Carvalho de Melo > wrote: > > > > On Mon, Nov 04, 2024 at 12:34:47PM -0800, Ian Rogers wrote: > > > On Mon, Nov 4, 2024 at 11:47 AM Namhyung Kim wrote: > > > > > > > > On Thu, Oct 31, 2024 at 01:51:36PM -0700, Ian Rogers wrote: > > > > > On Thu, Oct 31, 2024 at 12:18 PM Arnaldo Carvalho de Melo > > > > > wrote: > > > > > > > > > > > > On Wed, Oct 30, 2024 at 06:42:37PM -0700, Ian Rogers wrote: > > > > > > > The only use of find_scripts is in browser/scripts.c but the > > > > > > > definition in builtin causes linking problems requiring a stub in > > > > > > > python.c. Move the function to allow the stub to be removed. > > > > > > > > > > > > > > Rewrite the directory iteration to use openat so that large character > > > > > > > arrays aren't needed. The arrays are warned about potential buffer > > > > > > > overflows by GCC now that all the code exists in a single C file. > > > > > > > > > > > > Introducing is_directory_at() should be done as a prep patch, as the > > > > > > rest of the patch below could end up being reverted after some other > > > > > > patch used it, making the process more difficult. > > > > > > > > > > > > I mentioned cases like this in the past, so doing it again just for the > > > > > > record. > > > > > > > > > > This is highlighted in the commit message: > > > > > ``` > > > > > Rewrite the directory iteration to use openat so that large character > > > > > arrays aren't needed. The arrays are warned about potential buffer > > > > > overflows by GCC now that all the code exists in a single C file. > > > > > ``` > > > > > so without the change the code wouldn't build. The new is_directory_at > > > > > function is effectively 2 statements fstatat and S_ISDIR on the > > > > > result, it is put next to is_directory for consistency but could have > > > > > been a static function in the only C file to use it. > > > > > > > > > > For the record, patches introducing 2 line long functions can be > > > > > excessively noisy, especially in a 21 patch series. There is always > > > > > the declared but not used build error to worry about - here things > > > > > couldn't just be simply moved due to triggering a different build > > > > > error. Given the simplicity of the function here I made a decision not > > > > > to split up the work - the commit message would likely be longer than > > > > > the function. The work never intended to introduce is_directory_at but > > > > > was forced into it through a desire not to disable compiler warnings. > > > > > > > > This patch does more than just moving the code which can be easy to miss > > > > something in the middle. I think you can move the code as is without > > > > introducing build errors and then add new changes like using openat() on > > > > top (you may separate the change out of this series). I think it's > > > > ok to have a small change if it clearly has different semantics. > > > > > > If you are trying to bisect to find something that broke a build, > > > having commits that knowingly break the build will cause the bisect to > > > fail. The bisect will falsely fail on the known to be broken commit. > > > > I'm not understanding, AFAIK nobody is advocating for breaking > > bisection, just to first instroduce a function, then use it to avoid: > > > > 1) Introduce function foo() and use it for feature bar() > > 2) Somebody else uses function foo() > > 3) We find a justification to revert 1) but can't, since it will break > > 2) so we need to add 4) that removes bar() from 1). > > Namhyung was asking that the c&p of code be 1 patch then "add new > changes like using openat() on top". That is: > > patch 1: add is_directory_at - introduce the 2 line helper function > patch 2: move the code > patch 3: update the code to use is_directory_at > > patch 2 is known broken as patch 3 is fixing it. > > Hopefully this is clear. Actually I don't care about the patch ordering. My request is not to break build and just to separate different changes out. :) Thanks, Namhyung