As we really know how much space we have free in the buffers, we can send that information instead of guessing how much we can sent each time.
Signed-off-by: Juan Quintela <quint...@redhat.com> --- arch_init.c | 20 +++++++++----------- block-migration.c | 2 +- include/migration/vmstate.h | 2 +- include/sysemu/sysemu.h | 2 +- migration.c | 3 ++- savevm.c | 10 +++++++--- 6 files changed, 21 insertions(+), 18 deletions(-) diff --git a/arch_init.c b/arch_init.c index dada6de..2792b76 100644 --- a/arch_init.c +++ b/arch_init.c @@ -601,9 +601,12 @@ static int ram_save_setup(QEMUFile *f, void *opaque) return 0; } -static int ram_save_iterate(QEMUFile *f, void *opaque) +/* Maximum size for a transmited page + header + len + idstr + page size */ +#define MAX_PAGE_SIZE (8 + 1 + 256 + TARGET_PAGE_SIZE) + +static int ram_save_iterate(QEMUFile *f, void *opaque, uint64_t free_space) { - int ret; int i; int64_t t0; int total_sent = 0; @@ -616,15 +619,15 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) t0 = qemu_get_clock_ns(rt_clock); i = 0; - while ((ret = qemu_file_rate_limit(f)) == 0) { - int bytes_sent; - - bytes_sent = ram_save_block(f, false); + /* We need space for at least one page and end of section marker */ + while (free_space > MAX_PAGE_SIZE + 8) { + int bytes_sent = ram_save_block(f, false); /* no more blocks to sent */ if (bytes_sent == 0) { break; } total_sent += bytes_sent; + free_space -= bytes_sent; acct_info.iterations++; /* we want to check in the 1st loop, just in case it was the 1st time and we had to sync the dirty bitmap. @@ -644,11 +647,6 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) qemu_mutex_unlock_ramlist(); - if (ret < 0) { - bytes_transferred += total_sent; - return ret; - } - qemu_put_be64(f, RAM_SAVE_FLAG_EOS); total_sent += 8; bytes_transferred += total_sent; diff --git a/block-migration.c b/block-migration.c index 6acf3e1..0c3157a 100644 --- a/block-migration.c +++ b/block-migration.c @@ -535,7 +535,7 @@ static int block_save_setup(QEMUFile *f, void *opaque) return 0; } -static int block_save_iterate(QEMUFile *f, void *opaque) +static int block_save_iterate(QEMUFile *f, void *opaque, uint64_t free_space) { int ret; diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index f27276c..0b55cf4 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -33,7 +33,7 @@ typedef struct SaveVMHandlers { void (*set_params)(const MigrationParams *params, void * opaque); SaveStateHandler *save_state; int (*save_live_setup)(QEMUFile *f, void *opaque); - int (*save_live_iterate)(QEMUFile *f, void *opaque); + int (*save_live_iterate)(QEMUFile *f, void *opaque, uint64_t free_space); int (*save_live_complete)(QEMUFile *f, void *opaque); uint64_t (*save_live_pending)(QEMUFile *f, void *opaque, uint64_t max_size); void (*cancel)(void *opaque); diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h index d65a9f1..3ff043c 100644 --- a/include/sysemu/sysemu.h +++ b/include/sysemu/sysemu.h @@ -75,7 +75,7 @@ void qemu_announce_self(void); bool qemu_savevm_state_blocked(Error **errp); int qemu_savevm_state_begin(QEMUFile *f, const MigrationParams *params); -int qemu_savevm_state_iterate(QEMUFile *f); +int qemu_savevm_state_iterate(QEMUFile *f, uint64_t free_space); int qemu_savevm_state_complete(QEMUFile *f); void qemu_savevm_state_cancel(void); uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size); diff --git a/migration.c b/migration.c index 77c1971..e74ce49 100644 --- a/migration.c +++ b/migration.c @@ -683,6 +683,7 @@ static void *buffered_file_thread(void *opaque) while (true) { int64_t current_time = qemu_get_clock_ms(rt_clock); uint64_t pending_size; + size_t free_space = s->buffer_capacity - s->buffer_size; qemu_mutex_lock_iothread(); if (s->state != MIG_STATE_ACTIVE) { @@ -699,7 +700,7 @@ static void *buffered_file_thread(void *opaque) pending_size = qemu_savevm_state_pending(s->file, max_size); DPRINTF("pending size %lu max %lu\n", pending_size, max_size); if (pending_size && pending_size >= max_size) { - ret = qemu_savevm_state_iterate(s->file); + ret = qemu_savevm_state_iterate(s->file, free_space); if (ret < 0) { qemu_mutex_unlock_iothread(); break; diff --git a/savevm.c b/savevm.c index 913a623..3447f91 100644 --- a/savevm.c +++ b/savevm.c @@ -1609,10 +1609,11 @@ int qemu_savevm_state_begin(QEMUFile *f, * 0 : We haven't finished, caller have to go again * 1 : We have finished, we can go to complete phase */ -int qemu_savevm_state_iterate(QEMUFile *f) +int qemu_savevm_state_iterate(QEMUFile *f, uint64_t free_space) { SaveStateEntry *se; int ret = 1; + size_t remaining_space = free_space; QTAILQ_FOREACH(se, &savevm_handlers, entry) { if (!se->ops || !se->ops->save_live_iterate) { @@ -1629,9 +1630,11 @@ int qemu_savevm_state_iterate(QEMUFile *f) trace_savevm_section_start(); /* Section type */ qemu_put_byte(f, QEMU_VM_SECTION_PART); + remaining_space -= 1; qemu_put_be32(f, se->section_id); + remaining_space -= 4; - ret = se->ops->save_live_iterate(f, se->opaque); + ret = se->ops->save_live_iterate(f, se->opaque, remaining_space); trace_savevm_section_end(se->section_id); if (ret <= 0) { @@ -1641,6 +1644,7 @@ int qemu_savevm_state_iterate(QEMUFile *f) synchronized over and over again. */ break; } + remaining_space -= ret; } if (ret != 0) { return ret; @@ -1756,7 +1760,7 @@ static int qemu_savevm_state(QEMUFile *f) goto out; do { - ret = qemu_savevm_state_iterate(f); + ret = qemu_savevm_state_iterate(f, SIZE_MAX); if (ret < 0) goto out; } while (ret == 0); -- 1.8.1