Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030692AbWAJX1c (ORCPT ); Tue, 10 Jan 2006 18:27:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030688AbWAJX1A (ORCPT ); Tue, 10 Jan 2006 18:27:00 -0500 Received: from e32.co.us.ibm.com ([32.97.110.150]:56813 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S1030684AbWAJX0u (ORCPT ); Tue, 10 Jan 2006 18:26:50 -0500 Subject: [PATCH 5/5] ext3-get-blocks: Adjust reservation window size for mblocks From: Mingming Cao Reply-To: cmm@us.ibm.com To: Andrew Morton Cc: hch@lst.de, pbadari@us.ibm.com, "Stephen C. Tweedie" , linux-kernel , ext2-devel Content-Type: text/plain Organization: IBM LTC Date: Tue, 10 Jan 2006 15:26:48 -0800 Message-Id: <1136935608.4901.46.camel@dyn9047017067.beaverton.ibm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3014 Lines: 84 Last part of the multiple blocks allocation patch which optimize the block reservation and the multiple block allocation: with the knowledge of the total number of blocks ahead, set or adjust the reservation window size properly (based on the number of blocks needed) before block allocation happens: if there isn't any reservation yet, make sure the reservation window equals to or greater than the number of blocks needed, before create an reservation window; if a reservation window is already exists, try to extends the window size to match the number of blocks to allocate. This could increase the possibility of completing multiple blocks allocation in a single request, as blocks are only allocated in the range of the inode's reservation window. Signed-off-by: Mingming Cao --- linux-2.6.15-ming/fs/ext3/balloc.c | 32 +++++++++++++++++++++++++++++++- 1 files changed, 31 insertions(+), 1 deletion(-) diff -puN fs/ext3/balloc.c~ext3-extend-reservation fs/ext3/balloc.c --- linux-2.6.15/fs/ext3/balloc.c~ext3-extend-reservation 2006-01-10 14:18:18.462384575 -0800 +++ linux-2.6.15-ming/fs/ext3/balloc.c 2006-01-10 14:18:18.467383991 -0800 @@ -1012,6 +1012,31 @@ retry: goto retry; } +static void try_to_extend_reservation(struct ext3_reserve_window_node *my_rsv, + struct super_block *sb, int size) +{ + struct ext3_reserve_window_node *next_rsv; + struct rb_node *next; + spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock; + + if (!spin_trylock(rsv_lock)) + return; + + next = rb_next(&my_rsv->rsv_node); + + if (!next) + my_rsv->rsv_end += size; + else { + next_rsv = list_entry(next, struct ext3_reserve_window_node, rsv_node); + + if ((next_rsv->rsv_start - my_rsv->rsv_end -1) >= size) + my_rsv->rsv_end += size; + else + my_rsv->rsv_end = next_rsv->rsv_start -1 ; + } + spin_unlock(rsv_lock); +} + /* * This is the main function used to allocate a new block and its reservation * window. @@ -1096,6 +1121,8 @@ ext3_try_to_allocate_with_rsv(struct sup while (1) { if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) || !goal_in_my_reservation(&my_rsv->rsv_window, goal, group, sb)) { + if (my_rsv->rsv_goal_size < *count) + my_rsv->rsv_goal_size = *count; ret = alloc_new_reservation(my_rsv, goal, sb, group, bitmap_bh); if (ret < 0) @@ -1103,7 +1130,10 @@ ext3_try_to_allocate_with_rsv(struct sup if (!goal_in_my_reservation(&my_rsv->rsv_window, goal, group, sb)) goal = -1; - } + } else if (goal > 0 && (my_rsv->rsv_end-goal+1) < *count) + try_to_extend_reservation(my_rsv, sb, + *count-my_rsv->rsv_end+goal-1); + if ((my_rsv->rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb)) || (my_rsv->rsv_end < group_first_block)) BUG(); _ - 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/