From patchwork Fri May 12 14:57:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= X-Patchwork-Id: 13239448 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 75443C77B7C for ; Fri, 12 May 2023 14:58:26 +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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=waFDC0FctqamwwemQfiHMj4mwT4LRaQl2De1HM7vwfI=; b=AjwCPNxa6W6j2t uc1A1G5Q1WXfGbgBIWJX2DZZXoKqoIWzKbI2/44QHfe6LW6jvqUvrk7fwjonxP3qJ67q18nPt4fR8 x6MvRKCwBQXlyeJYLyvmGj2HFLTgk7icUTGzKW/YPANbl99/2JPY90KiZhhJUaxcCVe5PPoxi+lLW CSv/WHQmZfO3br9WBwUKpml0+X+9cvSNQ6vV6yAQSsQBXqGa3jlNbeMjqEIdv/c418LmMBZQKjiWn nFD37rHBZBIdz4eudeO7eFSAaH1dfET8CAFvPzuRVYIy/6N0ngH/sq56C4RbqgnfZx+cUKSyBy1mf HsqsbUSKXBaL2Ez07Iig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pxUDu-00CG6R-0c; Fri, 12 May 2023 14:58:22 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pxUDr-00CG4R-2O for linux-riscv@lists.infradead.org; Fri, 12 May 2023 14:58:21 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4735E655F5; Fri, 12 May 2023 14:58:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9BF1C4339C; Fri, 12 May 2023 14:58:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683903498; bh=lRwO3YfIMF9fmZSTE+/WO7BqWpiO2x+8QNF4La5hiEE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lFJE9ofAvx/W7GMthxymGs+b9O5oFO1BwdKIGcHaAN62YeWePDQ0N/sK71knTdSoF FVBIIqU4AmmF6IG79I2XtGg0JavzeJwFrHvwtyzSV76oVsE2HRceOMMnAX1c65IAP/ wzRAeUAfR4ibQ4s6pSnjOcUPEJrI0Uwkbd762zC/EYqhScoqAKaEuy84NEiMva3S8O cUjmxdLyvrJYLCFOB3H2n8gsVJcGT3aBKjaVsXZO/B0iymi2R+/sIoE+4yZ4U/slfd k0/FpzS+nNiLNCLb4BGq3Qd2jSem/r0rZlEnE2QEYIKn4OVGCS3P4sJXIb6FK2umT0 TTdE0MNOfw90w== From: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= To: Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv@lists.infradead.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Hildenbrand , Oscar Salvador , virtualization@lists.linux-foundation.org, linux@rivosinc.com, Alexandre Ghiti Subject: [PATCH 7/7] riscv: mm: Pre-allocate vmalloc PGD leaves Date: Fri, 12 May 2023 16:57:37 +0200 Message-Id: <20230512145737.985671-8-bjorn@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230512145737.985671-1-bjorn@kernel.org> References: <20230512145737.985671-1-bjorn@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230512_075819_825597_8784DD5B X-CRM114-Status: GOOD ( 14.09 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Björn Töpel Instead of relying on vmalloc_fault() to synchronize the page-tables, pre-allocate the PGD leaves of the vmalloc area. This is only enabled if memory hot/add is enabled by the build. Signed-off-by: Björn Töpel --- arch/riscv/mm/fault.c | 7 ++++++- arch/riscv/mm/init.c | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 8685f85a7474..b61e279acd50 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -233,12 +233,17 @@ void handle_page_fault(struct pt_regs *regs) * Fault-in kernel-space virtual memory on-demand. * The 'reference' page table is init_mm.pgd. * + * For memory hotplug enabled systems, the PGD entries are + * pre-allocated, which avoids the need to synchronize + * pgd/fault-in. + * * NOTE! We MUST NOT take any locks for this case. We may * be in an interrupt or a critical region, and should * only copy the information from the master page table, * nothing more. */ - if (unlikely((addr >= VMALLOC_START) && (addr < VMALLOC_END))) { + if (unlikely(!IS_ENABLED(CONFIG_MEMORY_HOTPLUG) && + (addr >= VMALLOC_START) && (addr < VMALLOC_END))) { vmalloc_fault(regs, code, addr); return; } diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index a468708d1e1c..fd5a6d3fe182 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -236,6 +236,7 @@ static void __init preallocate_pgd_pages_range(unsigned long start, unsigned lon static void __init prepare_memory_hotplug(void) { #ifdef CONFIG_MEMORY_HOTPLUG + preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc"); preallocate_pgd_pages_range(VMEMMAP_START, VMEMMAP_END, "vmemmap"); preallocate_pgd_pages_range(PAGE_OFFSET, PAGE_END, "direct map"); #endif