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[124.171.74.95]) by smtp.gmail.com with ESMTPSA id i4sm617438pjj.30.2022.01.17.18.53.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Jan 2022 18:53:01 -0800 (PST) Date: Tue, 18 Jan 2022 12:52:56 +1000 From: Nicholas Piggin Subject: Re: [PATCH v2 1/3] mm: vmalloc: Let user to control huge vmalloc default behavior To: Andrew Morton , Jonathan Corbet , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Kefeng Wang , x86@kernel.org Cc: =?iso-8859-1?q?Benjamin=0A?= Herrenschmidt , Borislav Petkov , Catalin Marinas , Christophe Leroy , Dave Hansen , "H. Peter Anvin" , Ingo Molnar , Michael Ellerman , Paul Mackerras , Thomas Gleixner , Will Deacon , Matthew Wilcox References: <20211227145903.187152-1-wangkefeng.wang@huawei.com> <20211227145903.187152-2-wangkefeng.wang@huawei.com> In-Reply-To: <20211227145903.187152-2-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Message-Id: <1642473992.qrnqczjfna.astroid@bobo.none> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Excerpts from Kefeng Wang's message of December 28, 2021 12:59 am: > Introduce HUGE_VMALLOC_DEFAULT_ENABLED and make it default y, this > let user to choose whether or not enable huge vmalloc mappings by > default. >=20 > Meanwhile, add new hugevmalloc=3Don/off parameter to enable or disable > this feature at boot time, nohugevmalloc is still supported and > equivalent to hugevmalloc=3Doff. Runtime options are bad enough, Kconfig and boot options are even worse. The 'nohugevmalloc' option mirrors 'nohugeiomap' and is not expected to ever be understood by an administrator unless a kernel developer is=20 working with them to hunt down a regression. IMO there should be no new options. You could switch it off for=20 CONFIG_BASE_SMALL perhaps, and otherwise just try to work on heuristics first. Bring in new options once it's proven they're needed. Aside from that, thanks for working on these ports, great work. Thanks, Nick 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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 05D60C43219 for ; Tue, 18 Jan 2022 02:53:48 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4JdCyg1vRLz3bTS for ; Tue, 18 Jan 2022 13:53:47 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=Uv5L+1MP; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::534; helo=mail-pg1-x534.google.com; envelope-from=npiggin@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=Uv5L+1MP; dkim-atps=neutral Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) (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 lists.ozlabs.org (Postfix) with ESMTPS id 4JdCxv1B5Qz2ynK for ; Tue, 18 Jan 2022 13:53:05 +1100 (AEDT) Received: by mail-pg1-x534.google.com with SMTP id s15so6157333pgs.1 for ; Mon, 17 Jan 2022 18:53:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:subject:to:cc:references:in-reply-to:mime-version :message-id:content-transfer-encoding; bh=+dXow2D6kovl8GlAwap0AWMuajUQM5lAihY8qrTDEBQ=; b=Uv5L+1MPSrZqYe6Y8HG3UarPEcwEh0vkALvNOq2xAcgsltUatlSZhvAu4ZkCRlnxRP FG+LVXfusldaMUz7UqtURH52quTwxGC4/yimq+EOUpXqGwqor+DRCSsIvtYOcwN5QHl5 W0R7HB/qG+3G2BxsGHl3Nt2xl43WRVP2gKUNTM1deSRo/DtHOwmzXiqK7q8tBs2HSebO pWYwrS/JgPs0ZJX5DjKnNjoEiljdIijhBH8X5esopzUOPtLubpjKOZixwwD4k2cn7/xZ xKKuycvIHwFIBOdVyt2yBQlZk3YaT50+wDcE8ANxk8CcAe3Avs5rNQ0FcOr7XVPi1ovc soLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:subject:to:cc:references:in-reply-to :mime-version:message-id:content-transfer-encoding; bh=+dXow2D6kovl8GlAwap0AWMuajUQM5lAihY8qrTDEBQ=; b=N4ROfgTyfKP06jEtWxxG20tNA3KRxth+aIsuqaBGnCLmtG9Hxd577uN8VuWh7N/ETY gqVHa89melm5G1VKw9rlgiqLo/RZHBaa9IJMq07pj2sRqDZNbuDznkx6+PsoCrAdMNTn hKiIC4DvecRW92JndSqfkV9OAKJKdmJnIa/7qZtYOrqHIYb3qXKaSjmV5JzMTAymxMOr oEF2v0Q1jjfQh+avNjbj40q6/yWjFOje/NeNrHQ066Rg+vnYkwnFdO8OWegN9A6FQbgs kHyfCcZ3ZJ8CpBkRdvQHM30euDvy1Gd/xLVmLcof1pOBdBKs1GSiTxJhwq8xhW7xgj3F FMaQ== X-Gm-Message-State: AOAM531d7F1afeD4JEQ5Tff9MXYH6RshknoCPdWHJF6SPSkCvVSjkDac 9jqlyjIG4rio3vTYKJ7Zfzg= X-Google-Smtp-Source: ABdhPJwyL7zGIsi9bIicvksHnAC4wjZ/DiXJE76/NAwmIpYKT6kHX1pZelN6IF0T1eLHS2LvHWGV5g== X-Received: by 2002:a05:6a00:23c8:b0:4c2:6a7:95c5 with SMTP id g8-20020a056a0023c800b004c206a795c5mr21194442pfc.53.1642474382328; Mon, 17 Jan 2022 18:53:02 -0800 (PST) Received: from localhost (124-171-74-95.tpgi.com.au. [124.171.74.95]) by smtp.gmail.com with ESMTPSA id i4sm617438pjj.30.2022.01.17.18.53.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Jan 2022 18:53:01 -0800 (PST) Date: Tue, 18 Jan 2022 12:52:56 +1000 From: Nicholas Piggin Subject: Re: [PATCH v2 1/3] mm: vmalloc: Let user to control huge vmalloc default behavior To: Andrew Morton , Jonathan Corbet , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Kefeng Wang , x86@kernel.org References: <20211227145903.187152-1-wangkefeng.wang@huawei.com> <20211227145903.187152-2-wangkefeng.wang@huawei.com> In-Reply-To: <20211227145903.187152-2-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Message-Id: <1642473992.qrnqczjfna.astroid@bobo.none> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Matthew Wilcox , Catalin Marinas , Dave Hansen , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Paul Mackerras , Thomas Gleixner , Will Deacon Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Excerpts from Kefeng Wang's message of December 28, 2021 12:59 am: > Introduce HUGE_VMALLOC_DEFAULT_ENABLED and make it default y, this > let user to choose whether or not enable huge vmalloc mappings by > default. >=20 > Meanwhile, add new hugevmalloc=3Don/off parameter to enable or disable > this feature at boot time, nohugevmalloc is still supported and > equivalent to hugevmalloc=3Doff. Runtime options are bad enough, Kconfig and boot options are even worse. The 'nohugevmalloc' option mirrors 'nohugeiomap' and is not expected to ever be understood by an administrator unless a kernel developer is=20 working with them to hunt down a regression. IMO there should be no new options. You could switch it off for=20 CONFIG_BASE_SMALL perhaps, and otherwise just try to work on heuristics first. Bring in new options once it's proven they're needed. Aside from that, thanks for working on these ports, great work. Thanks, Nick 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9A427C433F5 for ; Tue, 18 Jan 2022 03:40:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Message-Id:MIME-Version:In-Reply-To: References:Cc:To:Subject:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=R6+paTB650x9L5QHOY22mWn0lc+PLgQe2cFlDfbd6Hk=; b=FiEPvsKRml9CFG mumeAJKQqMmy+XxzOGgrmRP0TOQG8FjHPzyxAtNhTpXHqFESfvHWvOt2WdGHxEEDg9gUFYSq3XZYH 7KCKM9XsAgx2Hj956GF1OLt06lF8qaopahPK/0iiOO4u7fC1FyluIgY4GJr+maDA6xUjiJ49SN1sH LNp3PVF7EISOoVX3/T/mAp2x+EaVqLGOQcMbyQhE/9NYkynZtuyGwbHMaruHyJGemI76jD3ZkxM5x DNzuBIlaalqWYpnUdvFUlX5Pffft8WtoDsLGMJZI+RVjnr/vQuwYel4KmhVPgB7ZEF5u05RCKcV+M xcOKUgZM+7lEOsDyT8uA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9fKK-00HWIb-9G; Tue, 18 Jan 2022 03:38:33 +0000 Received: from mail-pf1-x42a.google.com ([2607:f8b0:4864:20::42a]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9ecJ-00H9YG-MR for linux-arm-kernel@lists.infradead.org; Tue, 18 Jan 2022 02:53:05 +0000 Received: by mail-pf1-x42a.google.com with SMTP id w204so11823671pfc.7 for ; Mon, 17 Jan 2022 18:53:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:subject:to:cc:references:in-reply-to:mime-version :message-id:content-transfer-encoding; bh=+dXow2D6kovl8GlAwap0AWMuajUQM5lAihY8qrTDEBQ=; b=Uv5L+1MPSrZqYe6Y8HG3UarPEcwEh0vkALvNOq2xAcgsltUatlSZhvAu4ZkCRlnxRP FG+LVXfusldaMUz7UqtURH52quTwxGC4/yimq+EOUpXqGwqor+DRCSsIvtYOcwN5QHl5 W0R7HB/qG+3G2BxsGHl3Nt2xl43WRVP2gKUNTM1deSRo/DtHOwmzXiqK7q8tBs2HSebO pWYwrS/JgPs0ZJX5DjKnNjoEiljdIijhBH8X5esopzUOPtLubpjKOZixwwD4k2cn7/xZ xKKuycvIHwFIBOdVyt2yBQlZk3YaT50+wDcE8ANxk8CcAe3Avs5rNQ0FcOr7XVPi1ovc soLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:subject:to:cc:references:in-reply-to :mime-version:message-id:content-transfer-encoding; bh=+dXow2D6kovl8GlAwap0AWMuajUQM5lAihY8qrTDEBQ=; b=tKUbOjQOHoi0A6nQqhzfL7yWckMSCdIcCEqX1LlnGS+ELbQR+MhOX5utDU165pzWRf rtOBeHz5/DDH2fsHAd8F1Yz8b33EMJxEMdJj2aZGSuLviZldOIM1qu8ILd4JEe1Rm0qb cIT3XyaIrt0q2OVuN1W9c6cU7isKDHpXWAetOAumWnbibufUz2gvWFc1N+IC9h2qaahc bd0a++g24ajwo7eC5qX71ka0dXPfqN6q5GsYfd95qvxxoEJV7wcUN2uI08CEFXW7C5bv qGzJspRQNwEKSNWG4R8lrqjW8JSpCTTzMG53NsNbgdzbweaLuzCPC+K/iBaq+XBvER6o Tc2g== X-Gm-Message-State: AOAM531WY06LRvuwYYqdbf0vRlJ7kofVCgul5vD3McnBP8C2hdGLSFhg Vmy62mj9K5UmBpRgeELh1gxWtDN5A8Q= X-Google-Smtp-Source: ABdhPJwyL7zGIsi9bIicvksHnAC4wjZ/DiXJE76/NAwmIpYKT6kHX1pZelN6IF0T1eLHS2LvHWGV5g== X-Received: by 2002:a05:6a00:23c8:b0:4c2:6a7:95c5 with SMTP id g8-20020a056a0023c800b004c206a795c5mr21194442pfc.53.1642474382328; Mon, 17 Jan 2022 18:53:02 -0800 (PST) Received: from localhost (124-171-74-95.tpgi.com.au. [124.171.74.95]) by smtp.gmail.com with ESMTPSA id i4sm617438pjj.30.2022.01.17.18.53.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Jan 2022 18:53:01 -0800 (PST) Date: Tue, 18 Jan 2022 12:52:56 +1000 From: Nicholas Piggin Subject: Re: [PATCH v2 1/3] mm: vmalloc: Let user to control huge vmalloc default behavior To: Andrew Morton , Jonathan Corbet , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, Kefeng Wang , x86@kernel.org Cc: =?iso-8859-1?q?Benjamin=0A?= Herrenschmidt , Borislav Petkov , Catalin Marinas , Christophe Leroy , Dave Hansen , "H. Peter Anvin" , Ingo Molnar , Michael Ellerman , Paul Mackerras , Thomas Gleixner , Will Deacon , Matthew Wilcox References: <20211227145903.187152-1-wangkefeng.wang@huawei.com> <20211227145903.187152-2-wangkefeng.wang@huawei.com> In-Reply-To: <20211227145903.187152-2-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Message-Id: <1642473992.qrnqczjfna.astroid@bobo.none> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220117_185303_805190_C7194BC2 X-CRM114-Status: GOOD ( 10.65 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Excerpts from Kefeng Wang's message of December 28, 2021 12:59 am: > Introduce HUGE_VMALLOC_DEFAULT_ENABLED and make it default y, this > let user to choose whether or not enable huge vmalloc mappings by > default. > > Meanwhile, add new hugevmalloc=on/off parameter to enable or disable > this feature at boot time, nohugevmalloc is still supported and > equivalent to hugevmalloc=off. Runtime options are bad enough, Kconfig and boot options are even worse. The 'nohugevmalloc' option mirrors 'nohugeiomap' and is not expected to ever be understood by an administrator unless a kernel developer is working with them to hunt down a regression. IMO there should be no new options. You could switch it off for CONFIG_BASE_SMALL perhaps, and otherwise just try to work on heuristics first. Bring in new options once it's proven they're needed. Aside from that, thanks for working on these ports, great work. Thanks, Nick _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel