From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id BE8316B005C for ; Fri, 22 May 2009 04:07:10 -0400 (EDT) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n4M87FmH021103 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Fri, 22 May 2009 17:07:15 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id DCFB745DE51 for ; Fri, 22 May 2009 17:07:14 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id BCEEB45DE4F for ; Fri, 22 May 2009 17:07:14 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id A8573E08001 for ; Fri, 22 May 2009 17:07:14 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 645251DB803F for ; Fri, 22 May 2009 17:07:14 +0900 (JST) Date: Fri, 22 May 2009 17:05:41 +0900 From: KAMEZAWA Hiroyuki Subject: [RFC][PATCH 3/3] count swap caches whose swp_entry can be freed. Message-Id: <20090522170541.ae14df90.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090522165730.8791c2dd.kamezawa.hiroyu@jp.fujitsu.com> References: <20090522165730.8791c2dd.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" , "hugh.dickins@tiscali.co.uk" , "akpm@linux-foundation.org" , "hannes@cmpxchg.org" List-ID: From: KAMEZAWA Hiroyuki Count a swap entry which is just a swapcache. i.e. swap entry can be freed immediately. This counter tells us there is a chance to reclaim swap entries. Maybe good for mem+swap controller. (Freeing routine itself is a homework...) Signed-off-by: KAMEZAWA Hiroyuki --- include/linux/swap.h | 1 + mm/swapfile.c | 15 ++++++++++++--- 2 files changed, 13 insertions(+), 3 deletions(-) Index: mmotm-2.6.30-May17/include/linux/swap.h =================================================================== --- mmotm-2.6.30-May17.orig/include/linux/swap.h +++ mmotm-2.6.30-May17/include/linux/swap.h @@ -156,6 +156,7 @@ struct swap_info_struct { unsigned int max; unsigned int inuse_pages; unsigned int old_block_size; + unsigned int orphan_swap_cache; }; struct swap_list_t { Index: mmotm-2.6.30-May17/mm/swapfile.c =================================================================== --- mmotm-2.6.30-May17.orig/mm/swapfile.c +++ mmotm-2.6.30-May17/mm/swapfile.c @@ -291,9 +291,10 @@ checks: si->lowest_bit = si->max; si->highest_bit = 0; } - if (cache) + if (cache) { si->swap_map[offset] = SWAP_HAS_CACHE; /* via get_swap_page() */ - else + si->orphan_swap_cache++; + } else si->swap_map[offset] = 1; /* via alloc_swap_block() */ si->cluster_next = offset + 1; @@ -521,9 +522,14 @@ static int swap_entry_free(struct swap_i swap_list.next = p - swap_info; nr_swap_pages++; p->inuse_pages--; + if (cache) + p->orphan_swap_cache--; } - if (!swap_has_ref(count)) + if (!swap_has_ref(count)) { mem_cgroup_uncharge_swap(ent); + if (count & SWAP_HAS_CACHE) + p->orphan_swap_cache++; + } return count; } @@ -2022,6 +2028,9 @@ int swap_duplicate(swp_entry_t entry) goto out_unlock; count = p->swap_map[offset] & SWAP_MAP_MASK; + if (!count && (p->swap_map[offset] & SWAP_HAS_CACHE)) + p->orphan_swap_cache++; + if (count < SWAP_MAP_MAX - 1) { p->swap_map[offset] += 1; result = 1; -- 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