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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DF96C31E5B for ; Mon, 17 Jun 2019 17:32:59 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 65F79208C0 for ; Mon, 17 Jun 2019 17:32:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="mDxIcTxr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 65F79208C0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=MqkJmnUgVI1X7+kTisdR/7h1x4BwrfSksk+dIroQvXs=; b=mDxIcTxracp96n f42+l+riFY8TrYebDuCT3EgjYQ8vNhcn5erf3jtkdzN6aGeUIDSQbLXW66baaKHPvp1RduDP8d6WR FLlR84uSS0fafKfBqznGF4BC7yOgTQljogk+jpUO6lhI6Wb9ImtCGswyBoJQFUENm5cGbTWeiT73q F2jmLG2lkFV9YoUew+THNPBpYMwIxfZ3fxJ6hyNEVy4G0w0OmlMpMj3IWTAKd+7Thgzsn9BE9oHqV geNqzegVsIPizLEwXo/RhLajYka+pzzOthJ7vwsb+BTolN0FcbGWpeHSlmlAx0xmLBzcIcqUGwhI8 Y8p+8JBZNLNXA8283/og==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hcvUv-0001P2-Hm; Mon, 17 Jun 2019 17:32:49 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hcvUr-0001OZ-LA for linux-arm-kernel@lists.infradead.org; Mon, 17 Jun 2019 17:32:46 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CADFE28; Mon, 17 Jun 2019 10:32:44 -0700 (PDT) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C6A293F246; Mon, 17 Jun 2019 10:32:43 -0700 (PDT) Date: Mon, 17 Jun 2019 18:32:41 +0100 From: Will Deacon To: Florian Fainelli Subject: Re: [PATCH] arm64: Allow user selection of ARM64_MODULE_PLTS Message-ID: <20190617173241.GM30800@fuggles.cambridge.arm.com> References: <20190614025932.533-1-f.fainelli@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190614025932.533-1-f.fainelli@gmail.com> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190617_103245_742722_14ECEBE5 X-CRM114-Status: GOOD ( 16.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ard.biesheuvel@linaro.org, Catalin Marinas , open list , bcm-kernel-feedback-list@Broadcom.com, linux-arm-kernel@vger.kernel.org, "moderated list:ARM64 PORT \(AARCH64 ARCHITECTURE\)" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jun 13, 2019 at 07:59:32PM -0700, Florian Fainelli wrote: > Make ARM64_MODULE_PLTS a selectable Kconfig symbol, since some people > might have very big modules spilling out of the dedicated module area > into vmalloc. Help text is copied from the ARM 32-bit counterpart. > > Signed-off-by: Florian Fainelli > --- > arch/arm64/Kconfig | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 697ea0510729..36befe987b73 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1418,8 +1418,20 @@ config ARM64_SVE > KVM in the same kernel image. > > config ARM64_MODULE_PLTS > - bool > + bool "Use PLTs to allow module memory to spill over into vmalloc area" > select HAVE_MOD_ARCH_SPECIFIC > + help > + Allocate PLTs when loading modules so that jumps and calls whose > + targets are too far away for their relative offsets to be encoded > + in the instructions themselves can be bounced via veneers in the > + module's PLT. This allows modules to be allocated in the generic > + vmalloc area after the dedicated module memory area has been > + exhausted. The modules will use slightly more memory, but after > + rounding up to page size, the actual memory footprint is usually > + the same. Isn't the worry really about the runtime performance overhead introduced by the veneers, as opposed to the memory usage of the module? > + Disabling this is usually safe for small single-platform > + configurations. If unsure, say y. So should this be on by default? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel