exec: adjust rcu_read_lock requirement

qemu_ram_unset_idstr() doesn't need rcu lock anymore,
meanwhile make the range of rcu lock in
qemu_ram_set_idstr() as small as possible.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Message-Id: <1462845901-89716-3-git-send-email-arei.gonglei@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Gonglei 2016-05-10 10:05:00 +08:00 committed by Paolo Bonzini
parent fa53a0e53e
commit ab0a995608
1 changed files with 1 additions and 5 deletions

6
exec.c
View File

@ -1421,8 +1421,6 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
{ {
RAMBlock *block; RAMBlock *block;
rcu_read_lock();
assert(new_block); assert(new_block);
assert(!new_block->idstr[0]); assert(!new_block->idstr[0]);
@ -1435,6 +1433,7 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
} }
pstrcat(new_block->idstr, sizeof(new_block->idstr), name); pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
rcu_read_lock();
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
if (block != new_block && if (block != new_block &&
!strcmp(block->idstr, new_block->idstr)) { !strcmp(block->idstr, new_block->idstr)) {
@ -1453,12 +1452,9 @@ void qemu_ram_unset_idstr(RAMBlock *block)
* migration. Ignore the problem since hot-unplug during migration * migration. Ignore the problem since hot-unplug during migration
* does not work anyway. * does not work anyway.
*/ */
rcu_read_lock();
if (block) { if (block) {
memset(block->idstr, 0, sizeof(block->idstr)); memset(block->idstr, 0, sizeof(block->idstr));
} }
rcu_read_unlock();
} }
static int memory_try_enable_merging(void *addr, size_t len) static int memory_try_enable_merging(void *addr, size_t len)