Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757917Ab0FBMUJ (ORCPT ); Wed, 2 Jun 2010 08:20:09 -0400 Received: from crca.org.au ([74.207.252.120]:37131 "EHLO crca.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757890Ab0FBMUG (ORCPT ); Wed, 2 Jun 2010 08:20:06 -0400 X-Bogosity: Ham, spamicity=0.000000 From: Nigel Cunningham To: "Rafael J. Wysocki" , Linux PM , LKML , TuxOnIce-devel Subject: [PATCH 04/21] Hibernation: Switch to preallocating swap. Date: Wed, 2 Jun 2010 22:19:03 +1000 Message-Id: <1275481160-31150-5-git-send-email-nigel@tuxonice.net> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1275481160-31150-1-git-send-email-nigel@tuxonice.net> References: <1275481160-31150-1-git-send-email-nigel@tuxonice.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4001 Lines: 135 Switch from allocating swap as the image is written to allocating storage prior to writing the image. Signed-off-by: Nigel Cunningham --- kernel/power/swap.c | 62 ++++++++++++++++++++++++++++++-------------------- 1 files changed, 37 insertions(+), 25 deletions(-) diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 550c1ed..ff2fc15 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -201,6 +201,33 @@ int alloc_swapdev_blocks(int needed) } /** + * allocate_swap - Allocate enough swap to save the image. + * + * Calculates the number of swap pages actually needed and seeks + * to allocate that many from the resume partition. Returns TRUE + * or FALSE to indicate whether we got enough storage. + */ + +static int allocate_swap(unsigned int nr_pages) +{ + unsigned int free_swap = count_swap_pages(root_swap, 1); + + nr_pages += DIV_ROUND_UP(nr_pages, MAP_PAGE_ENTRIES); + + pr_debug("PM: Free swap pages: %u\n", free_swap); + if (free_swap < nr_pages) + return 0; + + if (alloc_swapdev_blocks(nr_pages) < nr_pages) { + free_all_swap_pages(root_swap); + return 0; + } + + reset_storage_pos(); + return 1; +} + +/** * free_all_swap_pages - free swap pages allocated for saving image data. * It also frees the extents used to register which swap entres had been * allocated. @@ -321,7 +348,7 @@ static void release_swap_writer(struct swap_map_handle *handle) handle->cur = NULL; } -static int get_swap_writer(struct swap_map_handle *handle) +static int get_swap_writer(struct swap_map_handle *handle, unsigned long pages) { int ret; @@ -337,7 +364,12 @@ static int get_swap_writer(struct swap_map_handle *handle) ret = -ENOMEM; goto err_close; } - handle->cur_swap = alloc_swapdev_block(root_swap); + if (!allocate_swap(pages)) { + printk(KERN_ERR "PM: Not enough free swap\n"); + ret = -ENOSPC; + goto err_close; + } + handle->cur_swap = next_swapdev_block(); if (!handle->cur_swap) { ret = -ENOSPC; goto err_rel; @@ -360,7 +392,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf, if (!handle->cur) return -EINVAL; - offset = alloc_swapdev_block(root_swap); + offset = next_swapdev_block(); error = write_page(buf, offset, bio_chain); if (error) return error; @@ -369,7 +401,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf, error = hib_wait_on_bio_chain(bio_chain); if (error) goto out; - offset = alloc_swapdev_block(root_swap); + offset = next_swapdev_block(); if (!offset) return -ENOSPC; handle->cur->next_swap = offset; @@ -458,21 +490,6 @@ static int save_image(struct swap_map_handle *handle, } /** - * enough_swap - Make sure we have enough swap to save the image. - * - * Returns TRUE or FALSE after checking the total amount of swap - * space avaiable from the resume partition. - */ - -static int enough_swap(unsigned int nr_pages) -{ - unsigned int free_swap = count_swap_pages(root_swap, 1); - - pr_debug("PM: Free swap pages: %u\n", free_swap); - return free_swap > nr_pages + PAGES_FOR_IO; -} - -/** * swsusp_write - Write entire image and metadata. * @flags: flags to pass to the "boot" kernel in the image header * @@ -491,16 +508,11 @@ int swsusp_write(unsigned int flags) int error; pages = snapshot_get_image_size(); - error = get_swap_writer(&handle); + error = get_swap_writer(&handle, pages); if (error) { printk(KERN_ERR "PM: Cannot get swap writer\n"); return error; } - if (!enough_swap(pages)) { - printk(KERN_ERR "PM: Not enough free swap\n"); - error = -ENOSPC; - goto out_finish; - } memset(&snapshot, 0, sizeof(struct snapshot_handle)); error = snapshot_read_next(&snapshot); if (error < PAGE_SIZE) { -- 1.7.0.4 -- 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/