File 0154-Allow-extent_buffers-to-use-more-ram.patch of Package btrfsprogs

From 769671c6aeef3359498100f0ef31975706d99fca Mon Sep 17 00:00:00 2001
From: Chris Mason <chris.mason@oracle.com>
Date: Mon, 6 Feb 2012 05:06:18 -0500
Subject: [PATCH 03/18] Allow extent_buffers to use more ram

This changes free_some_buffers (called each time we allocate an extent
buffer) to allow a higher hard limit on the number of extent buffers
in use.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
 extent_io.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/extent_io.c b/extent_io.c
index 9990338..ebb35b2 100644
--- a/extent_io.c
+++ b/extent_io.c
@@ -28,7 +28,8 @@
 #include "extent_io.h"
 #include "list.h"
 
-u64 cache_max = 1024 * 1024 * 32;
+u64 cache_soft_max = 1024 * 1024 * 256;
+u64 cache_hard_max = 1 * 1024 * 1024 * 1024;
 
 void extent_io_tree_init(struct extent_io_tree *tree)
 {
@@ -540,18 +541,19 @@ static int free_some_buffers(struct extent_io_tree *tree)
 	struct extent_buffer *eb;
 	struct list_head *node, *next;
 
-	if (tree->cache_size < cache_max)
+	if (tree->cache_size < cache_soft_max)
 		return 0;
+
 	list_for_each_safe(node, next, &tree->lru) {
 		eb = list_entry(node, struct extent_buffer, lru);
 		if (eb->refs == 1) {
 			free_extent_buffer(eb);
-			if (tree->cache_size < cache_max)
+			if (tree->cache_size < cache_hard_max)
 				break;
 		} else {
 			list_move_tail(&eb->lru, &tree->lru);
 		}
-		if (nrscan++ > 64)
+		if (nrscan++ > 64 && tree->cache_size < cache_hard_max)
 			break;
 	}
 	return 0;
-- 
1.7.6.233.gd79bc