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[Qemu-devel] [PATCH 13/13] migration: flush receive queue
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PATCH 13/13] migration: flush receive queue |
Date: |
Fri, 21 Oct 2016 21:42:15 +0200 |
From: Juan Quintela <address@hidden>
Each time that we sync the bitmap, it is a possiblity that we receive
a page that is being processed by a different thread. We fix this
problem just making sure that we wait for all receiving threads to
finish its work before we procedeed with the next stage.
I tried to make a migration command for it, but it don't work because
we sync the bitmap sometimes when we have already sent the beggining
of the section, so I just added a new page flag.
Signed-off-by: Juan Quintela <address@hidden>
---
include/migration/migration.h | 1 +
migration/ram.c | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 41 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index afdc7ec..49e2ec6 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -251,6 +251,7 @@ void migrate_multifd_send_threads_create(void);
void migrate_multifd_send_threads_join(void);
void migrate_multifd_recv_threads_create(void);
void migrate_multifd_recv_threads_join(void);
+void qemu_savevm_send_multifd_flush(QEMUFile *f);
void migrate_compress_threads_create(void);
void migrate_compress_threads_join(void);
diff --git a/migration/ram.c b/migration/ram.c
index 9a20f63..bf2022e 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -69,6 +69,7 @@ static uint64_t bitmap_sync_count;
/* 0x80 is reserved in migration.h start with 0x100 next */
#define RAM_SAVE_FLAG_COMPRESS_PAGE 0x100
#define RAM_SAVE_FLAG_MULTIFD_PAGE 0x200
+#define RAM_SAVE_FLAG_MULTIFD_FLUSH 0x400
static const uint8_t ZERO_TARGET_PAGE[TARGET_PAGE_SIZE];
@@ -398,6 +399,11 @@ void migrate_compress_threads_create(void)
/* Multiple fd's */
+
+/* Indicates if we have synced the bitmap and we need to assure that
+ target has processeed all previous pages */
+bool multifd_needs_flush = false;
+
struct MultiFDSendParams {
/* not changed */
QemuThread thread;
@@ -713,6 +719,25 @@ static void multifd_recv_page(uint8_t *address, int fd_num)
qemu_mutex_unlock(¶ms->mutex);
}
+
+static int multifd_flush(void)
+{
+ int i, thread_count;
+
+ if (!migrate_multifd()) {
+ return 0;
+ }
+ thread_count = migrate_multifd_threads();
+ qemu_mutex_lock(&multifd_recv_mutex);
+ for (i = 0; i < thread_count; i++) {
+ while(!multifd_recv[i].done) {
+ qemu_cond_wait(&multifd_recv_cond, &multifd_recv_mutex);
+ }
+ }
+ qemu_mutex_unlock(&multifd_recv_mutex);
+ return 0;
+}
+
/**
* save_page_header: Write page header to wire
*
@@ -729,6 +754,11 @@ static size_t save_page_header(QEMUFile *f, RAMBlock
*block, ram_addr_t offset)
{
size_t size, len;
+ if (multifd_needs_flush) {
+ offset |= RAM_SAVE_FLAG_MULTIFD_FLUSH;
+ multifd_needs_flush = false;
+ }
+
qemu_put_be64(f, offset);
size = 8;
@@ -2399,6 +2429,9 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
if (!migration_in_postcopy(migrate_get_current())) {
migration_bitmap_sync();
+ if (migrate_multifd()) {
+ multifd_needs_flush = true;
+ }
}
ram_control_before_iterate(f, RAM_CONTROL_FINISH);
@@ -2440,6 +2473,9 @@ static void ram_save_pending(QEMUFile *f, void *opaque,
uint64_t max_size,
qemu_mutex_lock_iothread();
rcu_read_lock();
migration_bitmap_sync();
+ if (migrate_multifd()) {
+ multifd_needs_flush = true;
+ }
rcu_read_unlock();
qemu_mutex_unlock_iothread();
remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
@@ -2851,6 +2887,10 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
flags = addr & ~TARGET_PAGE_MASK;
addr &= TARGET_PAGE_MASK;
+ if (flags & RAM_SAVE_FLAG_MULTIFD_FLUSH) {
+ multifd_flush();
+ flags = flags & (~RAM_SAVE_FLAG_MULTIFD_FLUSH);
+ }
if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE |
RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE |
RAM_SAVE_FLAG_MULTIFD_PAGE)) {
--
2.7.4
- Re: [Qemu-devel] [PATCH 05/13] migration: create multifd migration threads, (continued)
- [Qemu-devel] [PATCH 06/13] migration: Start of multiple fd work, Juan Quintela, 2016/10/21
- [Qemu-devel] [PATCH 07/13] migration: create ram_multifd_page, Juan Quintela, 2016/10/21
- [Qemu-devel] [PATCH 09/13] migration: Send the fd number which we are going to use for this page, Juan Quintela, 2016/10/21
- [Qemu-devel] [PATCH 08/13] migration: Create thread infrastructure for multifd send side, Juan Quintela, 2016/10/21
- [Qemu-devel] [PATCH 11/13] migration: Test new fd infrastructure, Juan Quintela, 2016/10/21
- [Qemu-devel] [PATCH 10/13] migration: Create thread infrastructure for multifd recv side, Juan Quintela, 2016/10/21
- [Qemu-devel] [PATCH 12/13] migration: [HACK]Transfer pages over new channels, Juan Quintela, 2016/10/21
- [Qemu-devel] [PATCH 13/13] migration: flush receive queue,
Juan Quintela <=
- Re: [Qemu-devel] [RFC 00/13] Multifd v2, no-reply, 2016/10/21