Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754481AbYJQLeI (ORCPT ); Fri, 17 Oct 2008 07:34:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753126AbYJQLd4 (ORCPT ); Fri, 17 Oct 2008 07:33:56 -0400 Received: from iona.labri.fr ([147.210.8.143]:60214 "EHLO iona.labri.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752954AbYJQLdz (ORCPT ); Fri, 17 Oct 2008 07:33:55 -0400 Message-ID: <48F87885.5000606@inria.fr> Date: Fri, 17 Oct 2008 13:35:33 +0200 From: Brice Goglin User-Agent: Mozilla-Thunderbird 2.0.0.16 (X11/20080724) MIME-Version: 1.0 To: Christoph Lameter CC: LKML , linux-mm@kvack.org, Andrew Morton , Nathalie Furmento Subject: [RESEND][PATCH] mm: rework do_pages_move() to work on page_sized chunks References: <48F3AD47.1050301@inria.fr> <48F3AE1D.3060208@inria.fr> <48F79B42.3070106@linux-foundation.org> In-Reply-To: <48F79B42.3070106@linux-foundation.org> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3804 Lines: 136 Rework do_pages_move() to work by page-sized chunks of struct page_to_node that are passed to do_move_page_to_node_array(). We now only have to allocate a single page instead a possibly very large vmalloc area to store all page_to_node entries. As a result, new_page_node() will now have a very small lookup, hidding much of the overall sys_move_pages() overhead. Signed-off-by: Brice Goglin Signed-off-by: Nathalie Furmento --- mm/migrate.c | 79 ++++++++++++++++++++++++++++++++------------------------- 1 files changed, 44 insertions(+), 35 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index dffc98b..678589c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -947,41 +947,43 @@ static int do_pages_move(struct mm_struct *mm, struct task_struct *task, const int __user *nodes, int __user *status, int flags) { - struct page_to_node *pm = NULL; + struct page_to_node *pm; nodemask_t task_nodes; - int err = 0; - int i; + unsigned long chunk_nr_pages; + unsigned long chunk_start; + int err; task_nodes = cpuset_mems_allowed(task); - /* Limit nr_pages so that the multiplication may not overflow */ - if (nr_pages >= ULONG_MAX / sizeof(struct page_to_node) - 1) { - err = -E2BIG; - goto out; - } - - pm = vmalloc((nr_pages + 1) * sizeof(struct page_to_node)); - if (!pm) { - err = -ENOMEM; + err = -ENOMEM; + pm = (struct page_to_node *)__get_free_page(GFP_KERNEL); + if (!pm) goto out; - } - /* - * Get parameters from user space and initialize the pm - * array. Return various errors if the user did something wrong. + * Store a chunk of page_to_node array in a page, + * but keep the last one as a marker */ - for (i = 0; i < nr_pages; i++) { - const void __user *p; + chunk_nr_pages = (PAGE_SIZE / sizeof(struct page_to_node)) - 1; - err = -EFAULT; - if (get_user(p, pages + i)) - goto out_pm; + for (chunk_start = 0; + chunk_start < nr_pages; + chunk_start += chunk_nr_pages) { + int j; + + if (chunk_start + chunk_nr_pages > nr_pages) + chunk_nr_pages = nr_pages - chunk_start; - pm[i].addr = (unsigned long)p; - if (nodes) { + /* fill the chunk pm with addrs and nodes from user-space */ + for (j = 0; j < chunk_nr_pages; j++) { + const void __user *p; int node; - if (get_user(node, nodes + i)) + err = -EFAULT; + if (get_user(p, pages + j + chunk_start)) + goto out_pm; + pm[j].addr = (unsigned long) p; + + if (get_user(node, nodes + j + chunk_start)) goto out_pm; err = -ENODEV; @@ -992,22 +994,29 @@ static int do_pages_move(struct mm_struct *mm, struct task_struct *task, if (!node_isset(node, task_nodes)) goto out_pm; - pm[i].node = node; - } else - pm[i].node = 0; /* anything to not match MAX_NUMNODES */ - } - /* End marker */ - pm[nr_pages].node = MAX_NUMNODES; + pm[j].node = node; + } + + /* End marker for this chunk */ + pm[chunk_nr_pages].node = MAX_NUMNODES; + + /* Migrate this chunk */ + err = do_move_page_to_node_array(mm, pm, + flags & MPOL_MF_MOVE_ALL); + if (err < 0) + goto out_pm; - err = do_move_page_to_node_array(mm, pm, flags & MPOL_MF_MOVE_ALL); - if (err >= 0) /* Return status information */ - for (i = 0; i < nr_pages; i++) - if (put_user(pm[i].status, status + i)) + for (j = 0; j < chunk_nr_pages; j++) + if (put_user(pm[j].status, status + j + chunk_start)) { err = -EFAULT; + goto out_pm; + } + } + err = 0; out_pm: - vfree(pm); + free_page((unsigned long)pm); out: return err; } -- 1.5.6.5 -- 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/