Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933446AbbBIWqI (ORCPT ); Mon, 9 Feb 2015 17:46:08 -0500 Received: from g4t3426.houston.hp.com ([15.201.208.54]:43589 "EHLO g4t3426.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933366AbbBIWqG (ORCPT ); Mon, 9 Feb 2015 17:46:06 -0500 From: Toshi Kani To: akpm@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, arnd@arndb.de Cc: linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org, Elliott@hp.com, Toshi Kani Subject: [PATCH v2 7/7] mm: Add config HUGE_IOMAP to enable huge I/O mappings Date: Mon, 9 Feb 2015 15:45:35 -0700 Message-Id: <1423521935-17454-8-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1423521935-17454-1-git-send-email-toshi.kani@hp.com> References: <1423521935-17454-1-git-send-email-toshi.kani@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1252 Lines: 39 Add config HUGE_IOMAP to enable huge I/O mappings. This feature is set to Y by default when HAVE_ARCH_HUGE_VMAP is defined on the architecture. Note that user can also disable this feature at boot-time by the new kernel option "nohugeiomap" when necessary. Signed-off-by: Toshi Kani --- mm/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/mm/Kconfig b/mm/Kconfig index 1d1ae6b..eb738ae 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -444,6 +444,17 @@ choice benefit. endchoice +config HUGE_IOMAP + bool "Kernel huge I/O mapping support" + depends on HAVE_ARCH_HUGE_VMAP + default y + help + Kernel huge I/O mapping allows the kernel to transparently + create I/O mappings with huge pages for memory-mapped I/O + devices whenever possible. This feature can improve + performance of certain devices with large memory size, such + as NVM, and reduce the time to create their mappings. + # # UP and nommu archs use km based percpu allocator # -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/