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[Qemu-devel] [PATCH 8/9] exec: convert ram_list to QLIST
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From: |
Paolo Bonzini |
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Subject: |
[Qemu-devel] [PATCH 8/9] exec: convert ram_list to QLIST |
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Date: |
Fri, 6 Feb 2015 17:55:27 +0100 |
From: Mike Day <address@hidden>
QLIST has RCU-friendly primitives, so switch to it.
Signed-off-by: Mike Day <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
arch_init.c | 19 ++++++++--------
exec.c | 52 +++++++++++++++++++++++++-------------------
include/exec/cpu-all.h | 4 ++--
scripts/dump-guest-memory.py | 8 +++----
4 files changed, 46 insertions(+), 37 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index 71a539e..1ee2e35 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -523,7 +523,7 @@ static void migration_bitmap_sync(void)
trace_migration_bitmap_sync_start();
address_space_sync_dirty_bitmap(&address_space_memory);
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
migration_bitmap_sync_range(block->mr->ram_addr, block->used_length);
}
trace_migration_bitmap_sync_end(migration_dirty_pages
@@ -661,7 +661,7 @@ static int ram_find_and_save_block(QEMUFile *f, bool
last_stage)
MemoryRegion *mr;
if (!block)
- block = QTAILQ_FIRST(&ram_list.blocks);
+ block = QLIST_FIRST(&ram_list.blocks);
while (true) {
mr = block->mr;
@@ -672,9 +672,9 @@ static int ram_find_and_save_block(QEMUFile *f, bool
last_stage)
}
if (offset >= block->used_length) {
offset = 0;
- block = QTAILQ_NEXT(block, next);
+ block = QLIST_NEXT(block, next);
if (!block) {
- block = QTAILQ_FIRST(&ram_list.blocks);
+ block = QLIST_FIRST(&ram_list.blocks);
complete_round = true;
ram_bulk_stage = false;
}
@@ -728,8 +728,9 @@ uint64_t ram_bytes_total(void)
RAMBlock *block;
uint64_t total = 0;
- QTAILQ_FOREACH(block, &ram_list.blocks, next)
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
total += block->used_length;
+ }
return total;
}
@@ -831,7 +832,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
* gaps due to alignment or unplugs.
*/
migration_dirty_pages = 0;
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
uint64_t block_pages;
block_pages = block->used_length >> TARGET_PAGE_BITS;
@@ -844,7 +845,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
qemu_put_byte(f, strlen(block->idstr));
qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
qemu_put_be64(f, block->used_length);
@@ -1031,7 +1032,7 @@ static inline void *host_from_stream_offset(QEMUFile *f,
qemu_get_buffer(f, (uint8_t *)id, len);
id[len] = 0;
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
if (!strncmp(id, block->idstr, sizeof(id)) &&
block->max_length > offset) {
return memory_region_get_ram_ptr(block->mr) + offset;
@@ -1088,7 +1089,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
id[len] = 0;
length = qemu_get_be64(f);
- QTAILQ_FOREACH(block, &ram_list.blocks, next) {
+ QLIST_FOREACH(block, &ram_list.blocks, next) {
if (!strncmp(id, block->idstr, sizeof(id))) {
if (length != block->used_length) {
Error *local_err = NULL;
diff --git a/exec.c b/exec.c
index b039d5f..ea1f6c4 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 @@ static RAMBlock *qemu_get_ram_block(ram_addr_t addr)
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 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
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 @@ ram_addr_t last_ram_offset(void)
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 @@ static RAMBlock *find_ram_block(ram_addr_t addr)
{
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 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char
*name, DeviceState *dev)
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 @@ int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize,
Error **errp)
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 @@ static ram_addr_t ram_block_add(RAMBlock *new_block,
Error **errp)
}
}
- /* 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 @@ void qemu_ram_free_from_ptr(ram_addr_t addr)
/* 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, (void (*)(struct RAMBlock *))g_free, rcu);
@@ -1582,9 +1590,9 @@ void qemu_ram_free(ram_addr_t addr)
/* 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 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
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 @@ static void *qemu_ram_ptr_length(ram_addr_t addr, hwaddr
*size)
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 @@ MemoryRegion *qemu_ram_addr_from_host(void *ptr,
ram_addr_t *ram_addr)
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;
@@ -3015,7 +3023,7 @@ void qemu_ram_foreach_block(RAMBlockIterFunc func, void
*opaque)
{
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);
}
}
diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index f7a3625..87b8658 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -282,7 +282,7 @@ struct RAMBlock {
/* Reads can take either the iothread or the ramlist lock.
* Writes must take both locks.
*/
- QTAILQ_ENTRY(RAMBlock) next;
+ QLIST_ENTRY(RAMBlock) next;
int fd;
};
@@ -299,7 +299,7 @@ typedef struct RAMList {
unsigned long *dirty_memory[DIRTY_MEMORY_NUM];
RAMBlock *mru_block;
/* Protected by the ramlist lock. */
- QTAILQ_HEAD(, RAMBlock) blocks;
+ QLIST_HEAD(, RAMBlock) blocks;
uint32_t version;
} RAMList;
extern RAMList ram_list;
diff --git a/scripts/dump-guest-memory.py b/scripts/dump-guest-memory.py
index 1ed8b67..dc8e44a 100644
--- a/scripts/dump-guest-memory.py
+++ b/scripts/dump-guest-memory.py
@@ -108,16 +108,16 @@ shape and this command should mostly work."""
assert (val["hi"] == 0)
return val["lo"]
- def qtailq_foreach(self, head, field_str):
- var_p = head["tqh_first"]
+ def qlist_foreach(self, head, field_str):
+ var_p = head["lh_first"]
while (var_p != 0):
var = var_p.dereference()
yield var
- var_p = var[field_str]["tqe_next"]
+ var_p = var[field_str]["le_next"]
def qemu_get_ram_block(self, ram_addr):
ram_blocks = gdb.parse_and_eval("ram_list.blocks")
- for block in self.qtailq_foreach(ram_blocks, "next"):
+ for block in self.qlist_foreach(ram_blocks, "next"):
if (ram_addr - block["offset"] < block["length"]):
return block
raise gdb.GdbError("Bad ram offset %x" % ram_addr)
--
1.8.3.1
- [Qemu-devel] [PATCH v3 0/9] RCUification of the memory API, part 2, Paolo Bonzini, 2015/02/06
- [Qemu-devel] [PATCH 3/9] exec: RCUify AddressSpaceDispatch, Paolo Bonzini, 2015/02/06
- [Qemu-devel] [PATCH 5/9] rcu: introduce RCU-enabled QLIST, Paolo Bonzini, 2015/02/06
- [Qemu-devel] [PATCH 8/9] exec: convert ram_list to QLIST,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 1/9] exec: introduce cpu_reload_memory_map, Paolo Bonzini, 2015/02/06
- [Qemu-devel] [PATCH 7/9] cosmetic changes preparing for the following patches, Paolo Bonzini, 2015/02/06
- [Qemu-devel] [PATCH 6/9] exec: protect mru_block with RCU, Paolo Bonzini, 2015/02/06
- [Qemu-devel] [PATCH 2/9] exec: make iotlb RCU-friendly, Paolo Bonzini, 2015/02/06
- [Qemu-devel] [PATCH 4/9] rcu: prod call_rcu thread when calling synchronize_rcu, Paolo Bonzini, 2015/02/06
- [Qemu-devel] [PATCH 9/9] Convert ram_list to RCU, Paolo Bonzini, 2015/02/06