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[Qemu-devel] [PULL 15/21] migration: clean up xbzrle cache init/destroy
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PULL 15/21] migration: clean up xbzrle cache init/destroy |
Date: |
Mon, 23 Oct 2017 18:07:54 +0200 |
From: Peter Xu <address@hidden>
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>
Reviewed-by: Juan Quintela <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
---
migration/ram.c | 131 +++++++++++++++++++++++++++++++++++---------------------
1 file changed, 81 insertions(+), 50 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index d91e8787ae..60f9cfe8be 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1585,23 +1585,8 @@ static void ram_state_cleanup(RAMState **rsp)
*rsp = NULL;
}
-static void ram_save_cleanup(void *opaque)
+static void xbzrle_cleanup(void)
{
- RAMState **rsp = opaque;
- RAMBlock *block;
-
- /* caller have hold iothread lock or is in a bh, so there is
- * no writing race against this migration_bitmap
- */
- memory_global_dirty_log_stop();
-
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- g_free(block->bmap);
- block->bmap = NULL;
- g_free(block->unsentmap);
- block->unsentmap = NULL;
- }
-
XBZRLE_cache_lock();
if (XBZRLE.cache) {
cache_fini(XBZRLE.cache);
@@ -1614,6 +1599,26 @@ static void ram_save_cleanup(void *opaque)
XBZRLE.zero_target_page = NULL;
}
XBZRLE_cache_unlock();
+}
+
+static void ram_save_cleanup(void *opaque)
+{
+ RAMState **rsp = opaque;
+ RAMBlock *block;
+
+ /* caller have hold iothread lock or is in a bh, so there is
+ * no writing race against this migration_bitmap
+ */
+ memory_global_dirty_log_stop();
+
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ g_free(block->bmap);
+ block->bmap = NULL;
+ g_free(block->unsentmap);
+ block->unsentmap = NULL;
+ }
+
+ xbzrle_cleanup();
compress_threads_save_cleanup();
ram_state_cleanup(rsp);
}
@@ -2024,6 +2029,63 @@ err:
return ret;
}
+/*
+ * For every allocation, we will try not to crash the VM if the
+ * allocation failed.
+ */
+static int xbzrle_init(void)
+{
+ Error *local_err = NULL;
+
+ 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, &local_err);
+ if (!XBZRLE.cache) {
+ error_report_err(local_err);
+ 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);
@@ -2050,44 +2112,13 @@ static int ram_state_init(RAMState **rsp)
static int ram_init_all(RAMState **rsp)
{
- Error *local_err = NULL;
-
if (ram_state_init(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, &local_err);
- if (!XBZRLE.cache) {
- XBZRLE_cache_unlock();
- error_report_err(local_err);
- 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. */
--
2.13.6
- [Qemu-devel] [PULL 05/21] migration: Make cache_init() take an error parameter, (continued)
- [Qemu-devel] [PULL 05/21] migration: Make cache_init() take an error parameter, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 06/21] migration: Add 'pause-before-switchover' capability, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 08/21] migration: Wait for semaphore before completing migration, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 09/21] migration: migrate-continue, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 10/21] migrate: HMP migate_continue, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 07/21] migration: Add 'pre-switchover' and 'device' statuses, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 11/21] migration: allow cancel to unpause, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 12/21] migration: pause-before-switchover for postcopy, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 13/21] migration: provide ram_state_init(), Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 14/21] migration: provide ram_state_cleanup, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 15/21] migration: clean up xbzrle cache init/destroy,
Juan Quintela <=
- [Qemu-devel] [PULL 16/21] migration: new ram_init_bitmaps(), Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 17/21] migration: postcopy_place_page factoring out, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 20/21] qapi: Fix grammar in x-multifd-page-count descriptions, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 18/21] migration: introduce qemu_ufd_copy_ioctl helper, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 21/21] migration: Improve migration thread error handling, Juan Quintela, 2017/10/23
- [Qemu-devel] [PULL 19/21] migration: add bitmap for received page, Juan Quintela, 2017/10/23
- Re: [Qemu-devel] [PULL 00/21] Migration pull request, Peter Maydell, 2017/10/25