From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f171.google.com (mail-pd0-f171.google.com [209.85.192.171]) by kanga.kvack.org (Postfix) with ESMTP id B80446B0031 for ; Fri, 4 Oct 2013 09:52:53 -0400 (EDT) Received: by mail-pd0-f171.google.com with SMTP id g10so4034845pdj.2 for ; Fri, 04 Oct 2013 06:52:53 -0700 (PDT) From: "Marciniszyn, Mike" Subject: RE: [PATCH 23/26] ib: Convert qib_get_user_pages() to get_user_pages_unlocked() 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> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara , LKML Cc: "linux-mm@kvack.org" , infinipath , Roland Dreier , "linux-rdma@vger.kernel.org" > 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 f= ix > a bug in testing pinned number of pages when changing the code. >=20 This patch and the sibling ipath patch will nominally take the mmap_sem twi= ce 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org