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 6452A44AB6C; Fri, 25 Sep 2026 10:01:39 +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=1790330500; cv=none; b=qCdpaTgszfkNabOFO/UFNJhLaoFa/n65hm9tQneMkOGGhuggVeFRlJHLK4TxU/E2Zz8TKlOORUfxhC3PqMW50CDr9f6Z9BMJbTjrJBaeNBtfYeKPQcdNbZIVP+XBp6g7mM/iO7F37ifGbnPKoDuQrPGUPcomma0iQGkQWwBxUk8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790330500; c=relaxed/simple; bh=/pqGybG3gH7p6HG9P9eE+H322CVWdY9u2eX8pVq+/A8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JXcOeX3P3gDwT2HfrUxX+y3lTWlbRRsXTDqXGi+QdLvlX84B2qh1Li++H5+ReB8ONHDfORXAqF2Q9MzIv2qbosZtoJJU34QLdlr37n1fWQLw1F7HMQ1xaEMcIe9kLGRld+LiLbWhISjhY2P7z1bNsKiUz+0QQ7hdx4mGQ702uXQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QYwfCVG6; 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="QYwfCVG6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF8911F000FF; Fri, 25 Sep 2026 10:01:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790330498; bh=c1qtZNQkSLL9jY8cFQvdaU+DuydaEVSzJnJZ/ismFcI=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=QYwfCVG6JAMk9qByU+y21OUB9XibtfndvajO/P2w7i07XB6jM4pCcFfEi1rihN0Hq PPAeBGcD8eS9KCGS/SVfxF/uxjLrJWevPD8sjNr1R8XIxfToJi8pC9iLHsMY7yhhJK jWCMB8aF9MFdHncbuAbST10LwBnUox+VupAGDrMfxXrQAGn6toos+Kqon3eq6NFkFL JkQhaXFeC5Ojd3fXHIx+f++/u6WV+xe6ZIAE3v/e7s5+NTiCHAK62jLz4O37pFyDLe oLYAA9BKMOrOJX6vPzeWQklm3EmXoHI11TXkbqImkKOJQ3O7y32eQDSi9MSY1A4Ehc cXVjcto8MTV9Q== Received: from phl-compute-02.internal (phl-compute-02.internal [10.202.2.42]) by mailfauth.ams.internal (Postfix) with ESMTP id 919B6198003A; Fri, 25 Sep 2026 06:01:33 -0400 (EDT) Received: from phl-frontend-03 ([10.202.2.162]) by phl-compute-02.internal (MEProxy); Fri, 25 Sep 2026 06:01:36 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTFaHL7/M+1Ihc5bUYqYtFwJSgrnURianRf/JR5tgLUu7fXkjZXZfmxr42uVkLDENz n6CT7lbp4ydF0hj9OqU2bDAPnJ4sy7gAysDEagQgRgjtp5/JepVQ5/DqM747wnWVnxDpTm jrc4s8XALNefiP8J76+Wd9Svwha8zvIC0O9O96YtBwgD0mX6idSPc1uKI30oRERQlqN8L3 Lr8Ld3qlOHIm8iMljBRija5/BxhTJp2TXV2Mkb4SNPIlVJe3N64zVavtx9WdcYOkYU023N aDiaeR+VutG0GUjhSEsKc9hMRKknxanLE2/l1pwQvzn6kS5GFbP3ihVGhp6eMTXXkGvkBS AmeIHYIzhZ1yFuqqvqaHttceMfXxJ9esOyF3qN0yTrvFw5l7swuIkeiaIWZfmYXCLOkUxH VeWCFrW6XfDAicXxWHkznCBWbqieq0djlQ2YFijalVtJhux2dw5S6+WESijC+Z5SzkpHD8 6AP3T5/WJZ2Twln5733ADDWrueKkQAIHBNwGdZOaXqWW2Ih4AoS7VjqMXcHB/MboRVRphc DhHmLwygPFVFuzkxTsFkVJmQ+ak4ZvhUKjAEascAyCoLk6pNwzBmTcsQ4y24hX2qaB7OjP 0Bk2Z8itCVYzHmcxnXZN5gCoQguQAyxW7M12yG9pjkOqhVb6di6ypYXqSAig X-ME-Proxy: Feedback-ID: i10464835:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 25 Sep 2026 06:01:32 -0400 (EDT) Date: Fri, 25 Sep 2026 11:01:31 +0100 From: Kiryl Shutsemau To: Jason Gunthorpe Cc: Will Deacon , Robin Murphy , Joerg Roedel , Nicolin Chen , Pranjal Shrivastava , Mostafa Saleh , Thierry Reding , Krishna Reddy , Jonathan Hunter , Breno Leitao , Kyle McMartin , Usama Arif , kernel-team@meta.com, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 1/2] iommu/arm-smmu-v3: Add a cmdq_max_n_shift module parameter Message-ID: References: <20260909095228.2174031-1-kas@kernel.org> <20260909095228.2174031-2-kas@kernel.org> <179018301689.3334538.1783583175230817305.b4-review@b4> 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=us-ascii Content-Disposition: inline In-Reply-To: <179018301689.3334538.1783583175230817305.b4-review@b4> On Wed, Sep 23, 2026 at 02:03:36PM -0300, Jason Gunthorpe wrote: > > [ ... 34 lines skipped ... ] > > @@ -40,6 +40,11 @@ module_param(disable_msipolling, bool, 0444); > > MODULE_PARM_DESC(disable_msipolling, > > "Disable MSI-based polling for CMD_SYNC completion."); > > > > +static unsigned int cmdq_max_n_shift; > > +module_param(cmdq_max_n_shift, uint, 0444); > > +MODULE_PARM_DESC(cmdq_max_n_shift, > > + "Cap on the command queue depth, as log2 of the number of entries. Zero means the hardware maximum; the queue never shrinks below one page."); > > The patch looks ok > > Reviewed-by: Jason Gunthorpe > > But I'd rather use lg2 as name, especially user visible, instead of > n_shift. "shift" is a word for bitwise stuff, this is a 2**N log2 > encoded value. This name has changed twice already. v5 took the value in entries. Nicolin asked for a log2 value and named it after max_n_shift, which is what the driver calls this quantity everywhere else. I would rather not rename it a third time without input from the maintainer. Will, this is the user-visible name. Do you have a preference here? Unless you want it changed I will leave v6 as it is. -- Kiryl Shutsemau / Kirill A. Shutemov