From 6d68eec474cd4f3a1ce83211d9bd75025c3a62a9 Mon Sep 17 00:00:00 2001
From: iedowse <iedowse@FreeBSD.org>
Date: Mon, 2 Aug 2004 13:59:02 +0000
Subject: [PATCH] When searching for a suitable block of memory on the free
 list, skip blocks that are too big by a factor of two or greater. This avoids
 some cases of extremely inefficient memory use that can occur when large
 (e.g. 64k) blocks on the free list get used when allocating a 4k chunk of
 64-byte fragments. Because fragments have their own free list, the 60k
 difference got lost forever every time.

---
 sys/dev/usb/usb_mem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/dev/usb/usb_mem.c b/sys/dev/usb/usb_mem.c
index 73b309db4b1c..82b678e82b5c 100644
--- a/sys/dev/usb/usb_mem.c
+++ b/sys/dev/usb/usb_mem.c
@@ -142,7 +142,8 @@ usb_block_allocmem(bus_dma_tag_t tag, size_t size, size_t align,
 	s = splusb();
 	/* First check the free list. */
 	for (p = LIST_FIRST(&usb_blk_freelist); p; p = LIST_NEXT(p, next)) {
-		if (p->tag == tag && p->size >= size && p->align >= align) {
+		if (p->tag == tag && p->size >= size && p->size < size * 2 &&
+		    p->align >= align) {
 			LIST_REMOVE(p, next);
 			usb_blk_nfree--;
 			splx(s);