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[Qemu-devel] [PATCH 10/34] protect the ramlist with a separate mutex
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PATCH 10/34] protect the ramlist with a separate mutex |
Date: |
Wed, 19 Dec 2012 13:33:33 +0100 |
From: Umesh Deshpande <address@hidden>
Add the new mutex that protects shared state between ram_save_live
and the iothread. If the iothread mutex has to be taken together
with the ramlist mutex, the iothread shall always be _outside_.
Signed-off-by: Paolo Bonzini <address@hidden>
Signed-off-by: Umesh Deshpande <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
Reviewed-by: Orit Wasserman <address@hidden>
---
arch_init.c | 9 ++++++++-
cpu-all.h | 9 +++++++++
exec.c | 29 +++++++++++++++++++++++++++--
3 files changed, 44 insertions(+), 3 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index 136d0e8..9cee58a 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -528,7 +528,6 @@ static void ram_migration_cancel(void *opaque)
migration_end();
}
-
static void reset_ram_globals(void)
{
last_block = NULL;
@@ -547,6 +546,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
bitmap_set(migration_bitmap, 0, ram_pages);
migration_dirty_pages = ram_pages;
+ qemu_mutex_lock_ramlist();
bytes_transferred = 0;
reset_ram_globals();
@@ -574,6 +574,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
qemu_put_be64(f, block->length);
}
+ qemu_mutex_unlock_ramlist();
qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
return 0;
@@ -588,6 +589,8 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
uint64_t expected_downtime;
MigrationState *s = migrate_get_current();
+ qemu_mutex_lock_ramlist();
+
if (ram_list.version != last_version) {
reset_ram_globals();
}
@@ -636,6 +639,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
bwidth = 0.000001;
}
+ qemu_mutex_unlock_ramlist();
qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
expected_downtime = ram_save_remaining() * TARGET_PAGE_SIZE / bwidth;
@@ -656,6 +660,8 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
{
migration_bitmap_sync();
+ qemu_mutex_lock_ramlist();
+
/* try transferring iterative blocks of memory */
/* flush all remaining blocks regardless of rate limiting */
@@ -671,6 +677,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
}
migration_end();
+ qemu_mutex_unlock_ramlist();
qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
return 0;
diff --git a/cpu-all.h b/cpu-all.h
index c69d602..db79894 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -22,6 +22,7 @@
#include "qemu-common.h"
#include "qemu-tls.h"
#include "cpu-common.h"
+#include "qemu-thread.h"
/* some important defines:
*
@@ -487,6 +488,9 @@ typedef struct RAMBlock {
ram_addr_t length;
uint32_t flags;
char idstr[256];
+ /* Reads can take either the iothread or the ramlist lock.
+ * Writes must take both locks.
+ */
QTAILQ_ENTRY(RAMBlock) next;
#if defined(__linux__) && !defined(TARGET_S390X)
int fd;
@@ -494,8 +498,11 @@ typedef struct RAMBlock {
} RAMBlock;
typedef struct RAMList {
+ QemuMutex mutex;
+ /* Protected by the iothread lock. */
uint8_t *phys_dirty;
RAMBlock *mru_block;
+ /* Protected by the ramlist lock. */
QTAILQ_HEAD(, RAMBlock) blocks;
uint32_t version;
} RAMList;
@@ -516,6 +523,8 @@ extern int mem_prealloc;
void dump_exec_info(FILE *f, fprintf_function cpu_fprintf);
ram_addr_t last_ram_offset(void);
+void qemu_mutex_lock_ramlist(void);
+void qemu_mutex_unlock_ramlist(void);
#endif /* !CONFIG_USER_ONLY */
int cpu_memory_rw_debug(CPUArchState *env, target_ulong addr,
diff --git a/exec.c b/exec.c
index 4474d60..a43659b 100644
--- a/exec.c
+++ b/exec.c
@@ -212,6 +212,7 @@ bool memory_region_is_unassigned(MemoryRegion *mr)
void cpu_exec_init_all(void)
{
#if !defined(CONFIG_USER_ONLY)
+ qemu_mutex_init(&ram_list.mutex);
memory_map_init();
io_mem_init();
#endif
@@ -800,6 +801,16 @@ void qemu_flush_coalesced_mmio_buffer(void)
kvm_flush_coalesced_mmio_buffer();
}
+void qemu_mutex_lock_ramlist(void)
+{
+ qemu_mutex_lock(&ram_list.mutex);
+}
+
+void qemu_mutex_unlock_ramlist(void)
+{
+ qemu_mutex_unlock(&ram_list.mutex);
+}
+
#if defined(__linux__) && !defined(TARGET_S390X)
#include <sys/vfs.h>
@@ -981,6 +992,8 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char *name,
DeviceState *dev)
}
pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
+ /* This assumes the iothread lock is taken here too. */
+ qemu_mutex_lock_ramlist();
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
if (block != new_block && !strcmp(block->idstr, new_block->idstr)) {
fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
@@ -988,6 +1001,7 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char *name,
DeviceState *dev)
abort();
}
}
+ qemu_mutex_unlock_ramlist();
}
static int memory_try_enable_merging(void *addr, size_t len)
@@ -1011,6 +1025,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void
*host,
size = TARGET_PAGE_ALIGN(size);
new_block = g_malloc0(sizeof(*new_block));
+ /* This assumes the iothread lock is taken here too. */
+ qemu_mutex_lock_ramlist();
new_block->mr = mr;
new_block->offset = find_ram_offset(size);
if (host) {
@@ -1056,6 +1072,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void
*host,
ram_list.mru_block = NULL;
ram_list.version++;
+ qemu_mutex_unlock_ramlist();
ram_list.phys_dirty = g_realloc(ram_list.phys_dirty,
last_ram_offset() >> TARGET_PAGE_BITS);
@@ -1081,21 +1098,26 @@ void qemu_ram_free_from_ptr(ram_addr_t addr)
{
RAMBlock *block;
+ /* This assumes the iothread lock is taken here too. */
+ qemu_mutex_lock_ramlist();
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
if (addr == block->offset) {
QTAILQ_REMOVE(&ram_list.blocks, block, next);
ram_list.mru_block = NULL;
ram_list.version++;
g_free(block);
- return;
+ break;
}
}
+ qemu_mutex_unlock_ramlist();
}
void qemu_ram_free(ram_addr_t addr)
{
RAMBlock *block;
+ /* This assumes the iothread lock is taken here too. */
+ qemu_mutex_lock_ramlist();
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
if (addr == block->offset) {
QTAILQ_REMOVE(&ram_list.blocks, block, next);
@@ -1126,9 +1148,10 @@ void qemu_ram_free(ram_addr_t addr)
#endif
}
g_free(block);
- return;
+ break;
}
}
+ qemu_mutex_unlock_ramlist();
}
@@ -1206,6 +1229,7 @@ void *qemu_get_ram_ptr(ram_addr_t addr)
{
RAMBlock *block;
+ /* The list is protected by the iothread lock here. */
block = ram_list.mru_block;
if (block && addr - block->offset < block->length) {
goto found;
@@ -1245,6 +1269,7 @@ static void *qemu_safe_ram_ptr(ram_addr_t addr)
{
RAMBlock *block;
+ /* The list is protected by the iothread lock here. */
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
if (addr - block->offset < block->length) {
if (xen_enabled()) {
--
1.7.11.7
- [Qemu-devel] [PATCH 01/34] migration: fix migration_bitmap leak, (continued)
- [Qemu-devel] [PATCH 01/34] migration: fix migration_bitmap leak, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 02/34] buffered_file: do not send more than s->bytes_xfer bytes per tick, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 03/34] migration: remove double call to migrate_fd_close, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 04/34] migration: include qemu-file.h, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 05/34] migration-fd: remove duplicate include, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 07/34] exec: change RAM list to a TAILQ, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 06/34] exec: change ramlist from MRU order to a 1-item cache, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 09/34] add a version number to ram_list, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 08/34] exec: sort the memory from biggest to smallest, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 11/34] buffered_file: Move from using a timer to use a thread, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 10/34] protect the ramlist with a separate mutex,
Juan Quintela <=
- [Qemu-devel] [PATCH 13/34] migration: move migration thread init code to migrate_fd_put_ready, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 16/34] migration: just lock migrate_fd_put_ready, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 15/34] migration: remove unfreeze logic, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 14/34] migration: make writes blocking, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 18/34] buffered_file: don't flush on put buffer, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 17/34] buffered_file: Unfold the trick to restart generating migration data, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 22/34] migration: add XFER_LIMIT_RATIO, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 26/34] ram: rename last_block to last_seen_block, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 19/34] buffered_file: unfold buffered_append in buffered_put_buffer, Juan Quintela, 2012/12/19
- [Qemu-devel] [PATCH 12/34] migration: make qemu_fopen_ops_buffered() return void, Juan Quintela, 2012/12/19