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[Qemu-devel] [PATCH V9 09/20] COLO: Flush memory data from ram cache
From: |
Zhang Chen |
Subject: |
[Qemu-devel] [PATCH V9 09/20] COLO: Flush memory data from ram cache |
Date: |
Thu, 28 Jun 2018 04:41:25 +0800 |
During the time of VM's running, PVM may dirty some pages, we will transfer
PVM's dirty pages to SVM and store them into SVM's RAM cache at next checkpoint
time. So, the content of SVM's RAM cache will always be same with PVM's memory
after checkpoint.
Instead of flushing all content of PVM's RAM cache into SVM's MEMORY,
we do this in a more efficient way:
Only flush any page that dirtied by PVM since last checkpoint.
In this way, we can ensure SVM's memory same with PVM's.
Besides, we must ensure flush RAM cache before load device state.
Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
---
migration/ram.c | 37 +++++++++++++++++++++++++++++++++++++
migration/trace-events | 2 ++
2 files changed, 39 insertions(+)
diff --git a/migration/ram.c b/migration/ram.c
index ecc5f46068..4199d64ebd 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3370,6 +3370,39 @@ static bool postcopy_is_running(void)
return ps >= POSTCOPY_INCOMING_LISTENING && ps < POSTCOPY_INCOMING_END;
}
+/*
+ * Flush content of RAM cache into SVM's memory.
+ * Only flush the pages that be dirtied by PVM or SVM or both.
+ */
+static void colo_flush_ram_cache(void)
+{
+ RAMBlock *block = NULL;
+ void *dst_host;
+ void *src_host;
+ unsigned long offset = 0;
+
+ trace_colo_flush_ram_cache_begin(ram_state->migration_dirty_pages);
+ rcu_read_lock();
+ block = QLIST_FIRST_RCU(&ram_list.blocks);
+
+ while (block) {
+ offset = migration_bitmap_find_dirty(ram_state, block, offset);
+
+ if (offset << TARGET_PAGE_BITS >= block->used_length) {
+ offset = 0;
+ block = QLIST_NEXT_RCU(block, next);
+ } else {
+ migration_bitmap_clear_dirty(ram_state, block, offset);
+ dst_host = block->host + (offset << TARGET_PAGE_BITS);
+ src_host = block->colo_cache + (offset << TARGET_PAGE_BITS);
+ memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+ }
+ }
+
+ rcu_read_unlock();
+ trace_colo_flush_ram_cache_end();
+}
+
static int ram_load(QEMUFile *f, void *opaque, int version_id)
{
int flags = 0, ret = 0, invalid_flags = 0;
@@ -3545,6 +3578,10 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
ret |= wait_for_decompress_done();
rcu_read_unlock();
trace_ram_load_complete(ret, seq_iter);
+
+ if (!ret && migration_incoming_in_colo_state()) {
+ colo_flush_ram_cache();
+ }
return ret;
}
diff --git a/migration/trace-events b/migration/trace-events
index 86459d0580..6e1b58a6a3 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -90,6 +90,8 @@ ram_dirty_bitmap_sync_start(void) ""
ram_dirty_bitmap_sync_wait(void) ""
ram_dirty_bitmap_sync_complete(void) ""
ram_state_resume_prepare(uint64_t v) "%" PRId64
+colo_flush_ram_cache_begin(uint64_t dirty_pages) "dirty_pages %" PRIu64
+colo_flush_ram_cache_end(void) ""
# migration/migration.c
await_return_path_close_on_source_close(void) ""
--
2.17.GIT
- [Qemu-devel] [PATCH V9 00/20] COLO: integrate colo frame with block replication and COLO proxy, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 01/20] filter-rewriter: Add TCP state machine and fix memory leak in connection_track_table, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 02/20] colo-compare: implement the process of checkpoint, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 03/20] colo-compare: use notifier to notify packets comparing result, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 04/20] COLO: integrate colo compare with colo frame, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 05/20] COLO: Add block replication into colo process, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 06/20] COLO: Remove colo_state migration struct, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 07/20] COLO: Load dirty pages into SVM's RAM cache firstly, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 08/20] ram/COLO: Record the dirty pages that SVM received, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 09/20] COLO: Flush memory data from ram cache,
Zhang Chen <=
- [Qemu-devel] [PATCH V9 10/20] qmp event: Add COLO_EXIT event to notify users while exited COLO, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 11/20] qapi/migration.json: Rename COLO unknown mode to none mode., Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 12/20] qapi: Add new command to query colo status, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 14/20] COLO: flush host dirty ram from cache, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 13/20] savevm: split the process of different stages for loadvm/savevm, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 15/20] net/net.c: Add net client type check function for COLO, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 16/20] filter: Add handle_event method for NetFilterClass, Zhang Chen, 2018/06/27