From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lj1-f180.google.com (mail-lj1-f180.google.com [209.85.208.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F3FE224111A for ; Sat, 8 Feb 2025 18:42:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739040162; cv=none; b=qaf9kavU8CPS83SJEhWsXWHspD6X8RvALVsHM2sRan7oEyLqnkVnFoDiSPuk0CatQr0Yuif7kzthN7yUQOPnP9qz0NV6OBCAXJf3Eg4bOvCbkwUpPagOFE7ER0dKtowvuUuJgLhrTagi9AcF0cDDIU16ecWTZf14u9vfZx+cZJg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739040162; c=relaxed/simple; bh=9FjKQ/BoQv+CHpMARBhnQGJ+h9/ib6o+976NotBuoh8=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=mJoWmTPH5fepC79Hn4l+6pr+wu8K53LxjLCqcFcQ/9iT/HCwmOZq9hx9rhS4s+48FM3sb/QhUTgrbz1MLkCHqzf598l9iWORdYUeCihJZxKy6srVfLiUzODMrvPMMalJxKBMOcxToVQhWu0wElFjlyn8NI7gaqri3wGT31pklwo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=gAga5wxb; arc=none smtp.client-ip=209.85.208.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gAga5wxb" Received: by mail-lj1-f180.google.com with SMTP id 38308e7fff4ca-30613802a6bso33277131fa.1 for ; Sat, 08 Feb 2025 10:42:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1739040159; x=1739644959; darn=lists.linux-m68k.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=OF3d2v/Cd40GRW7Y3SKITD/wzvp4wTLT0QafaTbIXWQ=; b=gAga5wxbe0fWuwARq+T/QKU8nfkyw0XeUk6iKsrpBYC4/uacWjHZcUSTE7o/WYH7JJ 9VRrKhoYFfC2CGmEyHV0uY8e8VKZHyWLzPq69C7SBir1iCyrQBH2JcICnzk8+TLQxbdN ZE9l8NPtODuWFh8uzrHwOlyekCcn4ZSFujgsPf5U/pDDdVhjrCDzDbCi/gfnrIIOmocZ xUbFGiLSBq/gyXiZmYFuDduFDUnybWQK7XSL/Zatr5gJmKe4IPR3Ow+iE6uyxNB3naVA QD9W8zEyFInIoMRMvr0mvvQiQxQUsb/Eua7kopyQpaJyhmA2dYl/jR7o5A4LGysaNClf xH5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739040159; x=1739644959; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=OF3d2v/Cd40GRW7Y3SKITD/wzvp4wTLT0QafaTbIXWQ=; b=sch1bp41NGMkJ664m5OhS141IIiP88obD/B0IlDpfzLnf8CycOTI0pHkte0upBaAv+ QGPZQfXtWWmA4eAztynLFZs7taK+037nts5WeTplTj3oclNlxAmBdjOgjeKxnle/COFV 6yYug+lrrf0RuMlMwBJxq8OV2bTfTyHwY93koVUNbOtDKHCtB8zrs13vtCLLXftwgra4 qlrr3cL/KJdKyijVISbmPqkbgc0zEa6adpTafROyvi2jEEz7SOZkOVuiLAiASsmjW/63 IJpjsgkOTJJvxOqPxTYNO5bmaWuhTbrMutICTIB9HYFyviFVqt6RaNeie3Wk7kF6WHRs 3WNQ== X-Forwarded-Encrypted: i=1; AJvYcCUOVVvUOE5LUQlq/JTEB2YKYVTTFRsRN+4UU5/NxgCWSqVV5/kkeP0wLwWAYSypecJhmOmv8WnzRWgT@lists.linux-m68k.org X-Gm-Message-State: AOJu0YwIIcV52hwh5/QvWZs7iErGMrobUmxv/URV6vJulgTsCpoeZ3Qk YgOXHF41UPe30Z8tRwLE3jsBSkFxIapeXjhmbrXwDnoZ1ZCNviLe4pBNyHXhqYa9QqhwY++MAbV QY9Q6NNCJKKm+/GfNkcNo4qSMsA4= X-Gm-Gg: ASbGncu/hcmaoF8UzsbpjOF3u3C60FcSQGdrkCPbtJysRMWnG4Gqi8EOJYec+K4rKc4 txkibxkZBsBRIMBXLblN8hdLXu1+q7vvCPkmnmlgfh4q3wxYmefmhic3IxmdqqabRgx04I7ZbPh Qn2hwQ5O6dQ+bG3mv9RZslOZqtxCqsjBk= X-Google-Smtp-Source: AGHT+IE5yIE5Ue/y+RzFKL8z9km0wUX+8BN+VY4C0BGBjE9wQybUdFtxMRSR6CK8CWLDtOvu3dWumbmGNC9v45fv/pQ= X-Received: by 2002:a05:651c:199f:b0:307:dc1f:e469 with SMTP id 38308e7fff4ca-307e580c5d1mr26440881fa.20.1739040158468; Sat, 08 Feb 2025 10:42:38 -0800 (PST) Precedence: bulk X-Mailing-List: linux-m68k@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250207-bitmap-kunit-convert-v1-0-c520675343b6@gmail.com> In-Reply-To: From: Tamir Duberstein Date: Sat, 8 Feb 2025 13:42:02 -0500 X-Gm-Features: AWEUYZka1JKrPSYInI4GKv2M2y8rfwixxdFsdqTGcwpCPpsY53i6WsWMtdiDkWA Message-ID: Subject: Re: [PATCH 0/3] bitmap: convert self-test to KUnit To: Yury Norov Cc: David Gow , John Hubbard , Andrew Morton , Geert Uytterhoeven , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Rasmus Villemoes , Shuah Khan , Kees Cook , Muhammad Usama Anjum , linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linuxppc-dev@lists.ozlabs.org, linux-kselftest@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sat, Feb 8, 2025 at 12:53=E2=80=AFPM Yury Norov w= rote: > > [...] > > Take over means that you'd at least add the Co-developed-by tag. I didn't use their code - the thing being "taken over" is the work of having these debates with the maintainers. > [...] > > KUNIT is disabled in defconfig, at least on x86_64. It is also disabled > on my Ubuntu 24.04 machine. If I take your patches, I'll be unable to > boot-test bitmaps. Even worse, I'll be unable to build the standalone > test from sources as a module and load it later. > > Or I misunderstand it, and there's a way to build some particular KUNIT > test without enabling KUNIT in config and/or re-compiling the whole kerne= l? > Please teach me, if so > > Unless you give me a way to build and run the test in true > production environment, I'm not going with KUNITs. Sorry. This is a question for David -- I don't know if this is possible. > [...] > > This is my evidence: sometimes people report performance or whatever > issues on their systems, suspecting bitmaps guilty. I ask them to run > the bitmap or find_bit test to narrow the problem. Sometimes I need to > test a hardware I have no access to, and I have to (kindly!) ask people > to build a small test and run it. I don't want to ask them to rebuild > the whole kernel, or even to build something else. > > https://lore.kernel.org/all/YuWk3titnOiQACzC@yury-laptop/ This is compelling evidence, and it was not previously raised. Thank you. I notice that two things are true about the performance test part of test_bitmap.c: - It's a minority of the code in the file (48 lines out of 1462). - There are no assertions in it. Do you also find value in running the testing portion on other people's machines, to which you don't have access? > [...] > > Nice summary for the discussion. Unfortunately you missed my concerns. > Which are: > > Pros: > - Now we switch to KUNITs because KUNITs are so good > > Cons: > - Wipes git history; I was very careful to minimize churn, and the result is 249 lines on which I'd now own the blame (228 with `-w`). Still, it's a valid con. > - Bloats the test's source code; The test is 74 lines shorter after this series. > - Adds dependencies; > - Doesn't run on most popular distros and defconfig; Yep, I understand your concerns much better now - and I'm grateful for your having taken the time to explain and show receipts. Still, I wonder if we can get the best of both worlds - either by finding what you need in KUnit, or by moving the testing bit to KUnit and keeping the performance bit where it is. Thanks. Tamir