From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 B902718D655 for ; Tue, 6 Aug 2024 14:53:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722955986; cv=none; b=FsslzZOXVIL5t+d2F1ZxMd9kU7Qxbee9XnliBXwd1dUnZyB+iuK7WQ7QieKYUSmELkMdKRXR+w501PH3arYLodjxmK/Hg8hBMFB5HHhNsE2oCXlmsaw0vN6gu+WdfHm03TPrMzrmVcmPlo30BPBBuk572n/QXdUBflMS4fR62RA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722955986; c=relaxed/simple; bh=Nqo689t7LgKgBuMFfNk2N1oBq8U9vdikdPaK8ekHCNI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HpimIcVqERkmFLZa26heXHNKRWqSD5e5DYmOrcJW49fwLgIRr6RPEPUHM451Ow3E2kV3IlkZWhdtZiIfBZKbHvM9HC5jt2FFalfvw8+LSomd4c1GkM6208BP2YBSEBuTV3r26JP9uvzHrk3ti9osY+fotbe7I6suqfcCd4OBkkY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SfJFDIvX; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SfJFDIvX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722955983; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kw/gJMf5zY8eaBAGFwMXFDAn70FBRPyDWNFLg3x3Xm0=; b=SfJFDIvX69/nDb8MeU5gi6ke0oPNJDdOR8xmFtSze6Uc+GvQHTa24u36V+ywk+guNkl8uW Se7LEpl8guNHcxrZrr0c7xJYwXM3GJ2UHJ5W//9KTUGqUVMWo1SaY76epR5wxxrXH1rFRB 2d/8nSl1aTCjaaK6vzdATwrNzV+kZo8= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-213-gtB0QFl5Nqu--xTn1Ayd4w-1; Tue, 06 Aug 2024 10:52:58 -0400 X-MC-Unique: gtB0QFl5Nqu--xTn1Ayd4w-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 323E51955D59; Tue, 6 Aug 2024 14:52:55 +0000 (UTC) Received: from [10.2.16.146] (unknown [10.2.16.146]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 84F0D3001D85; Tue, 6 Aug 2024 14:52:53 +0000 (UTC) Message-ID: Date: Tue, 6 Aug 2024 10:52:52 -0400 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] lockdep: clarify size for LOCKDEP_*_BITS configs To: Carlos Llamas Cc: Andrew Morton , linux-kernel@vger.kernel.org, kernel-team@android.com, Peter Zijlstra , Boqun Feng , Ingo Molnar , Will Deacon References: <20240806010128.402852-1-cmllamas@google.com> <20240806010128.402852-3-cmllamas@google.com> <218314e9-7c7c-490c-bb2e-9611243cade3@redhat.com> Content-Language: en-US From: Waiman Long In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On 8/6/24 10:47, Carlos Llamas wrote: > On Mon, Aug 05, 2024 at 09:36:43PM -0400, Waiman Long wrote: >> Many kernel developers understand that BITS refers to a size of 2^n. Besides >> LOCKDEP, there are also many instances of such use in other kconfig entries. >> It can be a bit odd to explicitly state that just for LOCKDEP. >> >> Cheers, >> Longman > Right, and similar to BITS there is SHIFT, which is also a common way to > specify the 2^n values. I'd point out though, that it is also common to > clarify the "power of two" explicitly. To name a few examples that are > doing so: SECURITY_SELINUX_SIDTAB_HASH_BITS, NODES_SHIFT, CMA_ALIGNMENT, > IP_VS_SH_TAB_BITS, LOG_BUF_SHIFT but there is more. > > Perhaps this is because the audience for these configs is not always a > kernel developer? > > Anyway, this is pretty much a trivial patch to address Andrew's comment > below. But let me know if you think I should drop it, it seems to me it > can be helpful. > > [...] > btw, the help text "Bitsize for MAX_LOCKDEP_CHAINS" is odd. What's a > bitsize? Maybe "bit shift count for..." or such. I am not against this patch. Currently I am neutral. Let's see what Boqun think about it. Cheers, Longman