Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754911Ab3JDNwx (ORCPT ); Fri, 4 Oct 2013 09:52:53 -0400 Received: from mga02.intel.com ([134.134.136.20]:9597 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753755Ab3JDNwv convert rfc822-to-8bit (ORCPT ); Fri, 4 Oct 2013 09:52:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.90,1033,1371106800"; d="scan'208";a="414027005" From: "Marciniszyn, Mike" To: Jan Kara , LKML CC: "linux-mm@kvack.org" , infinipath , Roland Dreier , "linux-rdma@vger.kernel.org" Subject: RE: [PATCH 23/26] ib: Convert qib_get_user_pages() to get_user_pages_unlocked() Thread-Topic: [PATCH 23/26] ib: Convert qib_get_user_pages() to get_user_pages_unlocked() Thread-Index: AQHOv3vIHe5gOhmSsEGBHPLZHDmcI5nkkbDA Date: Fri, 4 Oct 2013 13:52:49 +0000 Message-ID: <32E1700B9017364D9B60AED9960492BC211B0176@FMSMSX107.amr.corp.intel.com> References: <1380724087-13927-1-git-send-email-jack@suse.cz> <1380724087-13927-24-git-send-email-jack@suse.cz> In-Reply-To: <1380724087-13927-24-git-send-email-jack@suse.cz> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.1.200.107] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1003 Lines: 20 > Convert qib_get_user_pages() to use get_user_pages_unlocked(). This > shortens the section where we hold mmap_sem for writing and also removes > the knowledge about get_user_pages() locking from ipath driver. We also fix > a bug in testing pinned number of pages when changing the code. > This patch and the sibling ipath patch will nominally take the mmap_sem twice where the old routine only took it once. This is a performance issue. Is the intent here to deprecate get_user_pages()? I agree, the old code's lock limit test is broke and needs to be fixed. I like the elimination of the silly wrapper routine! Could the lock limit test be pushed into another version of the wrapper so that there is only one set of mmap_sem transactions? Mike -- 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/