exec: convert ram_list to QLIST
QLIST has RCU-friendly primitives, so switch to it.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Mike Day <ncmike@ncultra.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/exec.c b/exec.c
index 2b6ee55..a7c2b92 100644
--- a/exec.c
+++ b/exec.c
@@ -58,7 +58,7 @@
#if !defined(CONFIG_USER_ONLY)
static bool in_migration;
-RAMList ram_list = { .blocks = QTAILQ_HEAD_INITIALIZER(ram_list.blocks) };
+RAMList ram_list = { .blocks = QLIST_HEAD_INITIALIZER(ram_list.blocks) };
static MemoryRegion *system_memory;
static MemoryRegion *system_io;
@@ -815,7 +815,7 @@
if (block && addr - block->offset < block->max_length) {
goto found;
}
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
if (addr - block->offset < block->max_length) {
goto found;
}
@@ -1197,15 +1197,16 @@
assert(size != 0); /* it would hand out same offset multiple times */
- if (QTAILQ_EMPTY(&ram_list.blocks))
+ if (QLIST_EMPTY(&ram_list.blocks)) {
return 0;
+ }
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
ram_addr_t end, next = RAM_ADDR_MAX;
end = block->offset + block->max_length;
- QTAILQ_FOREACH(next_block, &ram_list.blocks, next) {
+ QLIST_FOREACH(next_block, &ram_list.blocks, next) {
if (next_block->offset >= end) {
next = MIN(next, next_block->offset);
}
@@ -1230,9 +1231,9 @@
RAMBlock *block;
ram_addr_t last = 0;
- QTAILQ_FOREACH(block, &ram_list.blocks, next)
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
last = MAX(last, block->offset + block->max_length);
-
+ }
return last;
}
@@ -1256,7 +1257,7 @@
{
RAMBlock *block;
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
if (block->offset == addr) {
return block;
}
@@ -1284,7 +1285,7 @@
pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
qemu_mutex_lock_ramlist();
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
if (block != new_block && !strcmp(block->idstr, new_block->idstr)) {
fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
new_block->idstr);
@@ -1366,6 +1367,7 @@
static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp)
{
RAMBlock *block;
+ RAMBlock *last_block = NULL;
ram_addr_t old_ram_size, new_ram_size;
old_ram_size = last_ram_offset() >> TARGET_PAGE_BITS;
@@ -1392,16 +1394,22 @@
}
}
- /* Keep the list sorted from biggest to smallest block. */
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ /* Keep the list sorted from biggest to smallest block. Unlike QTAILQ,
+ * QLIST (which has an RCU-friendly variant) does not have insertion at
+ * tail, so save the last element in last_block.
+ */
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
+ last_block = block;
if (block->max_length < new_block->max_length) {
break;
}
}
if (block) {
- QTAILQ_INSERT_BEFORE(block, new_block, next);
- } else {
- QTAILQ_INSERT_TAIL(&ram_list.blocks, new_block, next);
+ QLIST_INSERT_BEFORE(block, new_block, next);
+ } else if (last_block) {
+ QLIST_INSERT_AFTER(last_block, new_block, next);
+ } else { /* list is empty */
+ QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
}
ram_list.mru_block = NULL;
@@ -1546,9 +1554,9 @@
/* This assumes the iothread lock is taken here too. */
qemu_mutex_lock_ramlist();
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
if (addr == block->offset) {
- QTAILQ_REMOVE(&ram_list.blocks, block, next);
+ QLIST_REMOVE(block, next);
ram_list.mru_block = NULL;
ram_list.version++;
g_free_rcu(block, rcu);
@@ -1582,9 +1590,9 @@
/* This assumes the iothread lock is taken here too. */
qemu_mutex_lock_ramlist();
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
if (addr == block->offset) {
- QTAILQ_REMOVE(&ram_list.blocks, block, next);
+ QLIST_REMOVE(block, next);
ram_list.mru_block = NULL;
ram_list.version++;
call_rcu(block, reclaim_ramblock, rcu);
@@ -1602,7 +1610,7 @@
int flags;
void *area, *vaddr;
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
offset = addr - block->offset;
if (offset < block->max_length) {
vaddr = ramblock_ptr(block, offset);
@@ -1707,7 +1715,7 @@
return xen_map_cache(addr, *size, 1);
} else {
RAMBlock *block;
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
if (addr - block->offset < block->max_length) {
if (addr - block->offset + *size > block->max_length)
*size = block->max_length - addr + block->offset;
@@ -1747,7 +1755,7 @@
goto found;
}
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
/* This case append when the block is not mapped. */
if (block->host == NULL) {
continue;
@@ -3019,7 +3027,7 @@
{
RAMBlock *block;
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
func(block->host, block->offset, block->used_length, opaque);
}
}