migration: protect the quit flag by lock

quit_comp_thread and quit_decomp_thread are accessed by several
thread, it's better to protect them with locks. We use a per
thread flag to replace the global one, and the new flag is protected
by a lock.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Message-Id: <1462433579-13691-7-git-send-email-liang.z.li@intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
This commit is contained in:
Liang Li 2016-05-05 15:32:56 +08:00 committed by Amit Shah
parent fc50438ed0
commit 90e56fb46d

View File

@ -255,6 +255,7 @@ static struct BitmapRcu {
struct CompressParam {
bool start;
bool done;
bool quit;
QEMUFile *file;
QemuMutex mutex;
QemuCond cond;
@ -266,6 +267,7 @@ typedef struct CompressParam CompressParam;
struct DecompressParam {
bool start;
bool done;
bool quit;
QemuMutex mutex;
QemuCond cond;
void *des;
@ -286,8 +288,6 @@ static QemuCond *comp_done_cond;
static const QEMUFileOps empty_ops = { };
static bool compression_switch;
static bool quit_comp_thread;
static bool quit_decomp_thread;
static DecompressParam *decomp_param;
static QemuThread *decompress_threads;
static QemuMutex decomp_done_lock;
@ -299,18 +299,18 @@ static void *do_data_compress(void *opaque)
{
CompressParam *param = opaque;
while (!quit_comp_thread) {
while (!param->quit) {
qemu_mutex_lock(&param->mutex);
/* Re-check the quit_comp_thread in case of
/* Re-check the quit flag in case of
* terminate_compression_threads is called just before
* qemu_mutex_lock(&param->mutex) and after
* while(!quit_comp_thread), re-check it here can make
* while(!param->quit), re-check it here can make
* sure the compression thread terminate as expected.
*/
while (!param->start && !quit_comp_thread) {
while (!param->start && !param->quit) {
qemu_cond_wait(&param->cond, &param->mutex);
}
if (!quit_comp_thread) {
if (!param->quit) {
do_compress_ram_page(param);
}
param->start = false;
@ -330,9 +330,9 @@ static inline void terminate_compression_threads(void)
int idx, thread_count;
thread_count = migrate_compress_threads();
quit_comp_thread = true;
for (idx = 0; idx < thread_count; idx++) {
qemu_mutex_lock(&comp_param[idx].mutex);
comp_param[idx].quit = true;
qemu_cond_signal(&comp_param[idx].cond);
qemu_mutex_unlock(&comp_param[idx].mutex);
}
@ -372,7 +372,6 @@ void migrate_compress_threads_create(void)
if (!migrate_use_compression()) {
return;
}
quit_comp_thread = false;
compression_switch = true;
thread_count = migrate_compress_threads();
compress_threads = g_new0(QemuThread, thread_count);
@ -387,6 +386,7 @@ void migrate_compress_threads_create(void)
*/
comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops);
comp_param[i].done = true;
comp_param[i].quit = false;
qemu_mutex_init(&comp_param[i].mutex);
qemu_cond_init(&comp_param[i].cond);
qemu_thread_create(compress_threads + i, "compress",
@ -863,12 +863,12 @@ static void flush_compressed_data(QEMUFile *f)
for (idx = 0; idx < thread_count; idx++) {
if (!comp_param[idx].done) {
qemu_mutex_lock(comp_done_lock);
while (!comp_param[idx].done && !quit_comp_thread) {
while (!comp_param[idx].done && !comp_param[idx].quit) {
qemu_cond_wait(comp_done_cond, comp_done_lock);
}
qemu_mutex_unlock(comp_done_lock);
}
if (!quit_comp_thread) {
if (!comp_param[idx].quit) {
len = qemu_put_qemu_file(f, comp_param[idx].file);
bytes_transferred += len;
}
@ -2203,12 +2203,12 @@ static void *do_data_decompress(void *opaque)
DecompressParam *param = opaque;
unsigned long pagesize;
while (!quit_decomp_thread) {
while (!param->quit) {
qemu_mutex_lock(&param->mutex);
while (!param->start && !quit_decomp_thread) {
while (!param->start && !param->quit) {
qemu_cond_wait(&param->cond, &param->mutex);
}
if (!quit_decomp_thread) {
if (!param->quit) {
pagesize = TARGET_PAGE_SIZE;
/* uncompress() will return failed in some case, especially
* when the page is dirted when doing the compression, it's
@ -2255,7 +2255,6 @@ void migrate_decompress_threads_create(void)
thread_count = migrate_decompress_threads();
decompress_threads = g_new0(QemuThread, thread_count);
decomp_param = g_new0(DecompressParam, thread_count);
quit_decomp_thread = false;
qemu_mutex_init(&decomp_done_lock);
qemu_cond_init(&decomp_done_cond);
for (i = 0; i < thread_count; i++) {
@ -2263,6 +2262,7 @@ void migrate_decompress_threads_create(void)
qemu_cond_init(&decomp_param[i].cond);
decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
decomp_param[i].done = true;
decomp_param[i].quit = false;
qemu_thread_create(decompress_threads + i, "decompress",
do_data_decompress, decomp_param + i,
QEMU_THREAD_JOINABLE);
@ -2273,10 +2273,10 @@ void migrate_decompress_threads_join(void)
{
int i, thread_count;
quit_decomp_thread = true;
thread_count = migrate_decompress_threads();
for (i = 0; i < thread_count; i++) {
qemu_mutex_lock(&decomp_param[i].mutex);
decomp_param[i].quit = true;
qemu_cond_signal(&decomp_param[i].cond);
qemu_mutex_unlock(&decomp_param[i].mutex);
}