Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754429AbXLRV6z (ORCPT ); Tue, 18 Dec 2007 16:58:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753691AbXLRV6r (ORCPT ); Tue, 18 Dec 2007 16:58:47 -0500 Received: from extu-mxob-2.symantec.com ([216.10.194.135]:59674 "EHLO extu-mxob-2.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753441AbXLRV6q (ORCPT ); Tue, 18 Dec 2007 16:58:46 -0500 Date: Tue, 18 Dec 2007 21:57:41 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@blonde.wat.veritas.com To: Andrew Morton cc: Christoph Rohland , linux-kernel@vger.kernel.org Subject: [PATCH 1/9] tmpfs: move swap_state stats update In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3674 Lines: 104 Both unionfs and memcgroups pose challenges to tmpfs and shmem. To help fix, it's best to move the swap swizzling functions from swap_state.c to shmem.c. As a preliminary to that, move swap stats updating down into __add_to_swap_cache, which will remain internal to swap_state.c. Well, actually, just move down the incrementation of add_total: remove noent_race and exist_race completely, they are relics of my 2.4.11 testing. Alt-SysRq-m users will be thrilled if 2.6.25 is at last free of "race M+N"s. Signed-off-by: Hugh Dickins --- checkpatch.pl would like me to add a KERN_level to the printk, but that's not something I want to get into here: this is one of a sequence of printks, some of which are per-arch, with different KERN_levels in different archs. Perhaps the remaining add/delete/find swap stats should be junked too; but they are of more general significance, so leave them for now. Nor do I want to get into removing that irritatingly repeated "Free swap" right now. mm/swap_state.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-) --- 2.6.24-rc5-mm1/mm/swap_state.c 2007-12-05 10:38:45.000000000 +0000 +++ tmpfs1/mm/swap_state.c 2007-12-05 16:42:16.000000000 +0000 @@ -52,16 +52,13 @@ static struct { unsigned long del_total; unsigned long find_success; unsigned long find_total; - unsigned long noent_race; - unsigned long exist_race; } swap_cache_info; void show_swap_cache_info(void) { - printk("Swap cache: add %lu, delete %lu, find %lu/%lu, race %lu+%lu\n", + printk("Swap cache: add %lu, delete %lu, find %lu/%lu\n", swap_cache_info.add_total, swap_cache_info.del_total, - swap_cache_info.find_success, swap_cache_info.find_total, - swap_cache_info.noent_race, swap_cache_info.exist_race); + swap_cache_info.find_success, swap_cache_info.find_total); printk("Free swap = %lukB\n", nr_swap_pages << (PAGE_SHIFT - 10)); printk("Total swap = %lukB\n", total_swap_pages << (PAGE_SHIFT - 10)); } @@ -89,6 +86,7 @@ static int __add_to_swap_cache(struct pa set_page_private(page, entry.val); total_swapcache_pages++; __inc_zone_page_state(page, NR_FILE_PAGES); + INC_CACHE_INFO(add_total); } write_unlock_irq(&swapper_space.tree_lock); radix_tree_preload_end(); @@ -102,10 +100,9 @@ static int add_to_swap_cache(struct page int error; BUG_ON(PageLocked(page)); - if (!swap_duplicate(entry)) { - INC_CACHE_INFO(noent_race); + if (!swap_duplicate(entry)) return -ENOENT; - } + SetPageLocked(page); error = __add_to_swap_cache(page, entry, gfp_mask & GFP_KERNEL); /* @@ -114,11 +111,8 @@ static int add_to_swap_cache(struct page if (error) { ClearPageLocked(page); swap_free(entry); - if (error == -EEXIST) - INC_CACHE_INFO(exist_race); return error; } - INC_CACHE_INFO(add_total); return 0; } @@ -178,11 +172,9 @@ int add_to_swap(struct page * page, gfp_ case 0: /* Success */ SetPageUptodate(page); SetPageDirty(page); - INC_CACHE_INFO(add_total); return 1; case -EEXIST: /* Raced with "speculative" read_swap_cache_async */ - INC_CACHE_INFO(exist_race); swap_free(entry); continue; default: @@ -225,9 +217,7 @@ int move_to_swap_cache(struct page *page if (!swap_duplicate(entry)) BUG(); SetPageDirty(page); - INC_CACHE_INFO(add_total); - } else if (err == -EEXIST) - INC_CACHE_INFO(exist_race); + } return err; } -- 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/