[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 3/4] migration: clean up xbzrle cache init/destroy
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH 3/4] migration: clean up xbzrle cache init/destroy |
Date: |
Thu, 19 Oct 2017 14:31:59 +0800 |
Let's further simplify ram_init_all() and ram_save_cleanup() by abstract
all the XBZRLE related codes into their own functions.
When allocating xbzrle cache, we are always very careful on -ENOMEM;
which makes sense. Replacing the last g_malloc0() with g_try_malloc0(),
then refactor the logic a bit.
This patch should be fixing some memory leaks when some memory
allocation failed for XBZRLE in the past.
Signed-off-by: Peter Xu <address@hidden>
---
migration/ram.c | 121 +++++++++++++++++++++++++++++++++++---------------------
1 file changed, 76 insertions(+), 45 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 72c48e76e9..3df7715d63 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1575,6 +1575,22 @@ static void ram_state_cleanup(RAMState **rsp)
*rsp = NULL;
}
+static void xbzrle_cleanup(void)
+{
+ XBZRLE_cache_lock();
+ if (XBZRLE.cache) {
+ cache_fini(XBZRLE.cache);
+ g_free(XBZRLE.encoded_buf);
+ g_free(XBZRLE.current_buf);
+ g_free(XBZRLE.zero_target_page);
+ XBZRLE.cache = NULL;
+ XBZRLE.encoded_buf = NULL;
+ XBZRLE.current_buf = NULL;
+ XBZRLE.zero_target_page = NULL;
+ }
+ XBZRLE_cache_unlock();
+}
+
static void ram_save_cleanup(void *opaque)
{
RAMState **rsp = opaque;
@@ -1592,18 +1608,7 @@ static void ram_save_cleanup(void *opaque)
block->unsentmap = NULL;
}
- XBZRLE_cache_lock();
- if (XBZRLE.cache) {
- cache_fini(XBZRLE.cache);
- g_free(XBZRLE.encoded_buf);
- g_free(XBZRLE.current_buf);
- g_free(XBZRLE.zero_target_page);
- XBZRLE.cache = NULL;
- XBZRLE.encoded_buf = NULL;
- XBZRLE.current_buf = NULL;
- XBZRLE.zero_target_page = NULL;
- }
- XBZRLE_cache_unlock();
+ xbzrle_cleanup();
compress_threads_save_cleanup();
ram_state_cleanup(rsp);
}
@@ -2014,6 +2019,62 @@ err:
return ret;
}
+/*
+ * For every allocation, we will try not to crash the VM if the
+ * allocation failed.
+ */
+static int xbzrle_init(void)
+{
+ if (!migrate_use_xbzrle()) {
+ return 0;
+ }
+
+ XBZRLE_cache_lock();
+
+ XBZRLE.zero_target_page = g_try_malloc0(TARGET_PAGE_SIZE);
+ if (!XBZRLE.zero_target_page) {
+ error_report("%s: Error allocating zero page", __func__);
+ goto err_out;
+ }
+
+ XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
+ TARGET_PAGE_SIZE,
+ TARGET_PAGE_SIZE);
+ if (!XBZRLE.cache) {
+ error_report("%s: Error creating cache", __func__);
+ goto free_zero_page;
+ }
+
+ XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
+ if (!XBZRLE.encoded_buf) {
+ error_report("%s: Error allocating encoded_buf", __func__);
+ goto free_cache;
+ }
+
+ XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
+ if (!XBZRLE.current_buf) {
+ error_report("%s: Error allocating current_buf", __func__);
+ goto free_encoded_buf;
+ }
+
+ /* We are all good */
+ XBZRLE_cache_unlock();
+ return 0;
+
+free_encoded_buf:
+ g_free(XBZRLE.encoded_buf);
+ XBZRLE.encoded_buf = NULL;
+free_cache:
+ cache_fini(XBZRLE.cache);
+ XBZRLE.cache = NULL;
+free_zero_page:
+ g_free(XBZRLE.zero_target_page);
+ XBZRLE.zero_target_page = NULL;
+err_out:
+ XBZRLE_cache_unlock();
+ return -ENOMEM;
+}
+
static int ram_state_init(RAMState **rsp)
{
*rsp = g_try_new0(RAMState, 1);
@@ -2044,39 +2105,9 @@ static int ram_init_all(RAMState **rsp)
return -1;
}
- if (migrate_use_xbzrle()) {
- XBZRLE_cache_lock();
- XBZRLE.zero_target_page = g_malloc0(TARGET_PAGE_SIZE);
- XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
- TARGET_PAGE_SIZE,
- TARGET_PAGE_SIZE);
- if (!XBZRLE.cache) {
- XBZRLE_cache_unlock();
- error_report("Error creating cache");
- g_free(*rsp);
- *rsp = NULL;
- return -1;
- }
- XBZRLE_cache_unlock();
-
- /* We prefer not to abort if there is no memory */
- XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
- if (!XBZRLE.encoded_buf) {
- error_report("Error allocating encoded_buf");
- g_free(*rsp);
- *rsp = NULL;
- return -1;
- }
-
- XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
- if (!XBZRLE.current_buf) {
- error_report("Error allocating current_buf");
- g_free(XBZRLE.encoded_buf);
- XBZRLE.encoded_buf = NULL;
- g_free(*rsp);
- *rsp = NULL;
- return -1;
- }
+ if (xbzrle_init()) {
+ ram_state_cleanup(rsp);
+ return -1;
}
/* For memory_global_dirty_log_start below. */
--
2.13.5