From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D20E1EB64D7 for ; Fri, 23 Jun 2023 17:34:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231933AbjFWReV (ORCPT ); Fri, 23 Jun 2023 13:34:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbjFWReS (ORCPT ); Fri, 23 Jun 2023 13:34:18 -0400 Received: from mailbox.box.xen0n.name (mail.xen0n.name [115.28.160.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B745E1FC2; Fri, 23 Jun 2023 10:34:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=xen0n.name; s=mail; t=1687541652; bh=uijmNbUmIlHkh56jJTNP2T+S8lHX64iWOnrHTLZxmMY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=c7ReWnrwTc9Z/yK/YxC63JsOxA9Ryx737DuAuXNPnXzjONrx43KxaW58qqTnmf5wa vcBAKCY6htQxSV4Ljc8ozyQ9fQAqvAKLzv2/2cTylYnPWouKP8/3deP8ypWTkbt+hO JkcqaXhSmlP1nGMj2yVoRdr+ONFZJkcIRgT8V2AU= Received: from [192.168.9.172] (unknown [101.88.25.181]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by mailbox.box.xen0n.name (Postfix) with ESMTPSA id E9C0C600A9; Sat, 24 Jun 2023 01:34:11 +0800 (CST) Message-ID: Date: Sat, 24 Jun 2023 01:34:11 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH] LoongArch: Add SMT (Simultaneous Multi-Threading) support Content-Language: en-US To: "Rafael J. Wysocki" , Huacai Chen Cc: Liupu Wang , Len Brown , Jianmin Lv , Marc Zyngier , Tiezhu Yang , Binbin Zhou , Bibo Mao , Josh Poimboeuf , loongarch@lists.linux.dev, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Huacai Chen References: <20230614093755.88881-1-wangliupu@loongson.cn> From: WANG Xuerui In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 6/24/23 01:20, Rafael J. Wysocki wrote: > On Thu, Jun 15, 2023 at 4:31 AM Huacai Chen wrote: >> Hi, Rafael, >> >> On Thu, Jun 15, 2023 at 2:24 AM Rafael J. Wysocki wrote: >>> On Wed, Jun 14, 2023 at 11:38 AM Liupu Wang wrote: >>>> [snip] >>>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig >>>> index ccbeab9500ec..00dd309b6682 100644 >>>> --- a/drivers/acpi/Kconfig >>>> +++ b/drivers/acpi/Kconfig >>>> @@ -542,10 +542,10 @@ config ACPI_PFRUT >>>> >>>> if ARM64 >>>> source "drivers/acpi/arm64/Kconfig" >>>> +endif >>>> >>>> config ACPI_PPTT >>>> bool >>>> -endif >>> x86 doesn't use PPTT as of today. Why do you enable it for them? >> ACPI_PPTT is an invisible symbol, it cannot be enabled by explicitly >> selecting and its default value is n, so I think it isn't enabled for >> x86. On the other hand, moving it out of ARM64 can make other archs >> don't need to modify this file any more if they need PPTT. > AFAICS, setting ACPI_PPTT causes pptt.c to be compiled and if it is > never going to be used by the given arch, it will just be dead code. > > Can't this be avoided? FYI I've just tried a x86_64 defconfig build and ACPI_PPTT isn't being enabled, nor is there a pptt.o signifying the same thing. > drivers/acpi/Makefile > 109:obj-$(CONFIG_ACPI_PPTT)     += pptt.o This should mean that, if nothing is selecting ACPI_PPTT then the file isn't going to be compiled? Right now it seems only arch/arm64 and arch/loongarch are doing so based on my cursory grep. Or do you mean we should be extra careful and keep the guard around the symbol to ensure it's nonexistent on other irrelevant arches? -- WANG "xen0n" Xuerui Linux/LoongArch mailing list: https://lore.kernel.org/loongarch/