From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 44FFB35AC27; Thu, 28 May 2026 07:54:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779954853; cv=none; b=uR572iqCEkE4NoBxMq4Sz/DrNlnYDxBiWZ/ja6xay/66T7utbAlTC2GWAWUS5ZROQIi6p7xJyX52mjZznUkLfhnhgLr8G53nhmDDABmqsTHM8gK+aWj7W6ZP5L0X0Fl1pKm2RXLOwL2wRSylxl8fV3QlYoExEGRIhXeg1eh8a7Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779954853; c=relaxed/simple; bh=6LhxpZ3jp/TRJAOmy1MQ4RP2/xjjrAWe43OmHikPpTw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=iMgfpptg0ZFhf91RYhEgiUK+7NdCtlLzAQZLPq5JElk2nnxMW62weTHy2oh3y2Tt5r8gqLx0wwmeE5m0TWHFZYyy2ZE2Md6zK8laVK5jF8Us//GAYwBEBcI9cWUIhEaaE0GUFuzHuUam0PDY/wtrsWiP8w+svRohNWzdkNdbEUY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VMjrDY9P; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VMjrDY9P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9356E1F000E9; Thu, 28 May 2026 07:54:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779954852; bh=DXyX/vSlotir1MvkerBIJgI1i61yQB1gKf3by/+LUNM=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=VMjrDY9Pl3stXYQe+Hx8eLna86X/Ey4PyiJtR5xorT1OA8XptvPgr3Kq85FgSVgNh XR5ZRMbBKfKNps0UVTzXEY41Ic+sODBxgi/xjj9tPCy+Ql2pHaWWCgA/L/SIkQY6n/ rUyS+sJi7qt+Lcj/pLTsdZQRxS3LbGoiTQsXMd/KzNA1MBtfs30uncfKm54xfbyX5S Z3uKgxF21zys8QvrAUiNCE3/eibp0rmcLMiUVLuVLOlhQaO6XWudf3wGznREbnm86m fCv+Tq/bLgD8uIQB/KRD09em28nvvNanynmcl6DzZrTHJ18DJ4H4zz3/fAErmSlw9s uMQJeq3+ON0SA== Message-ID: <146b3bdf-0219-4eae-a569-6ffb3d5ea400@kernel.org> Date: Thu, 28 May 2026 09:54:07 +0200 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/mempool: use static key for boot-time debug enablement Content-Language: en-US To: Andrew Morton , lirongqing , Usama Arif Cc: Jonathan Corbet , Shuah Khan , Harry Yoo , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20260527104634.2434-1-lirongqing@baidu.com> <20260527130656.a448e84a30dc44617b51b45a@linux-foundation.org> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/27/26 22:06, Andrew Morton wrote: > On Wed, 27 May 2026 06:46:34 -0400 lirongqing wrote: > >> Replace the #ifdef CONFIG_SLUB_DEBUG_ON conditional compilation with a >> static key (mempool_debug_enabled). This allows enabling mempool debugging >> at boot time via: >> >> mempool_debug >> >> Instead of requiring CONFIG_SLUB_DEBUG_ON at compile time. Benefits: > > Sashiko is suggesting that we use mempool_debug=<...> here. Which permits > mempool_debug=n if for some reason the kernel is defaulting to "on". Which > we might choose to do in the future. I think that's a little better - do others agree? Yeah we could do that. But I still think "CONFIG_SLUB_DEBUG_ON" isn't what should cause mempool_debug to default to "on". It can be revisited once there's a solid argument why default on would be needed. > Same goes for the new dmapool_debug. Ack. > Sashiko asked a second question: > https://sashiko.dev/#/patchset/20260527104634.2434-1-lirongqing@baidu.com Seems the same thing as Usama raised about static key init ordering.