From patchwork Tue May 6 15:30:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 4122421 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 297B09F23C for ; Tue, 6 May 2014 15:34:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 60D4E201EF for ; Tue, 6 May 2014 15:34:09 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6772D201ED for ; Tue, 6 May 2014 15:34:08 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WhhLh-0000t8-8N; Tue, 06 May 2014 15:32:05 +0000 Received: from mail-wi0-f182.google.com ([209.85.212.182]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WhhKc-0008JH-0P for linux-arm-kernel@lists.infradead.org; Tue, 06 May 2014 15:30:59 +0000 Received: by mail-wi0-f182.google.com with SMTP id r20so1161727wiv.9 for ; Tue, 06 May 2014 08:30:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=TWutVXjm73mfg0jJqtCD5xY/9WNbID5XXyjIA1udg5c=; b=XNCP97TIi3FMHrBFGs431lfAbNui9mQx/dKdwUG53eBUpeZqYLtmf0S5w92Nfqqbjx xzLPjjFhCGnfa46qhdjI9RB6NzT0+015R1N6ol8WmFs0n9ZfdfRnd3gITatH2+m6f/tC EhYl2Q4AvT+rDeObbpNSB4j+K51aUque+7l+lWYGc+AqIrxH0T39iaES7FSdSpPUHcpc Yzmah03E/AgJKWn7SmonMgDFqszuZieF0nNC61GVMN5XQZsM1PpYDNxNelH65lEDv9MM e/wGO+VRJyd9T+3O5aZl66IwE2gOFgvx/NSyLJWRt+Ru3HRcL/LUTmDkpaJfK8a/zc71 uOXQ== X-Gm-Message-State: ALoCoQnufhIvXnnloRioPyMQ55VUdi8YMjdweoQOW79+njzfb8d1VB6Rh42ynFN+va7bELDMC5L3 X-Received: by 10.180.14.199 with SMTP id r7mr21628759wic.0.1399390235287; Tue, 06 May 2014 08:30:35 -0700 (PDT) Received: from marmot.wormnet.eu (marmot.wormnet.eu. [188.246.204.87]) by mx.google.com with ESMTPSA id ho2sm2330106wib.15.2014.05.06.08.30.33 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 May 2014 08:30:34 -0700 (PDT) From: Steve Capper To: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, linux@arm.linux.org.uk, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH V5 6/6] arm64: mm: Enable RCU fast_gup Date: Tue, 6 May 2014 16:30:09 +0100 Message-Id: <1399390209-1756-7-git-send-email-steve.capper@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1399390209-1756-1-git-send-email-steve.capper@linaro.org> References: <1399390209-1756-1-git-send-email-steve.capper@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140506_083058_275031_D9BEFDBC X-CRM114-Status: GOOD ( 12.84 ) X-Spam-Score: -0.7 (/) Cc: anders.roxell@linaro.org, peterz@infradead.org, gary.robertson@linaro.org, will.deacon@arm.com, Steve Capper , akpm@linux-foundation.org, christoffer.dall@linaro.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Activate the RCU fast_gup for ARM64. We also need to force THP splits to broadcast an IPI s.t. we block in the fast_gup page walker. As THP splits are comparatively rare, this should not lead to a noticeable performance degradation. Signed-off-by: Steve Capper --- arch/arm64/Kconfig | 3 +++ arch/arm64/include/asm/pgtable.h | 8 +++++++- arch/arm64/mm/flush.c | 19 +++++++++++++++++++ 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 2420390..5168949 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -95,6 +95,9 @@ config GENERIC_CALIBRATE_DELAY config ZONE_DMA def_bool y +config HAVE_RCU_GUP + def_bool y + config ARCH_DMA_ADDR_T_64BIT def_bool y diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 90c811f..126ed77e 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -244,7 +244,13 @@ static inline pmd_t pte_pmd(pte_t pte) #ifdef CONFIG_TRANSPARENT_HUGEPAGE #define pmd_trans_huge(pmd) (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT)) #define pmd_trans_splitting(pmd) pte_special(pmd_pte(pmd)) -#endif +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH +struct vm_area_struct; +void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp); +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #define pmd_young(pmd) pte_young(pmd_pte(pmd)) #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index e4193e3..ddf96c1 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -103,3 +103,22 @@ EXPORT_SYMBOL(flush_dcache_page); */ EXPORT_SYMBOL(flush_cache_all); EXPORT_SYMBOL(flush_icache_range); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +static void thp_splitting_flush_sync(void *arg) +{ +} + +void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp) +{ + pmd_t pmd = pmd_mksplitting(*pmdp); + VM_BUG_ON(address & ~PMD_MASK); + set_pmd_at(vma->vm_mm, address, pmdp, pmd); + + /* dummy IPI to serialise against fast_gup */ + smp_call_function(thp_splitting_flush_sync, NULL, 1); +} +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */