Commit 14bcfdc7 authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Juan Quintela

Split ram_save_block

ram_save_block is getting a bit too complicated, and does two separate
things:
   1) Finds a page to send
   2) Sends the page (dealing with compression etc)

Split into 'ram_save_page' to send the page and deal with compression (2)
Rename remaining function to 'ram_find_and_save_block'
Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent fb626663
......@@ -560,20 +560,93 @@ static void migration_bitmap_sync(void)
}
/*
* ram_save_block: Writes a page of memory to the stream f
* ram_save_page: Send the given page to the stream
*
* Returns: Number of bytes written.
*/
static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
bool last_stage)
{
int bytes_sent;
int cont;
ram_addr_t current_addr;
MemoryRegion *mr = block->mr;
uint8_t *p;
int ret;
bool send_async = true;
cont = (block == last_sent_block) ? RAM_SAVE_FLAG_CONTINUE : 0;
p = memory_region_get_ram_ptr(mr) + offset;
/* In doubt sent page as normal */
bytes_sent = -1;
ret = ram_control_save_page(f, block->offset,
offset, TARGET_PAGE_SIZE, &bytes_sent);
XBZRLE_cache_lock();
current_addr = block->offset + offset;
if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
if (ret != RAM_SAVE_CONTROL_DELAYED) {
if (bytes_sent > 0) {
acct_info.norm_pages++;
} else if (bytes_sent == 0) {
acct_info.dup_pages++;
}
}
} else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
acct_info.dup_pages++;
bytes_sent = save_block_hdr(f, block, offset, cont,
RAM_SAVE_FLAG_COMPRESS);
qemu_put_byte(f, 0);
bytes_sent++;
/* Must let xbzrle know, otherwise a previous (now 0'd) cached
* page would be stale
*/
xbzrle_cache_zero_page(current_addr);
} else if (!ram_bulk_stage && migrate_use_xbzrle()) {
bytes_sent = save_xbzrle_page(f, &p, current_addr, block,
offset, cont, last_stage);
if (!last_stage) {
/* Can't send this cached data async, since the cache page
* might get updated before it gets to the wire
*/
send_async = false;
}
}
/* XBZRLE overflow or normal page */
if (bytes_sent == -1) {
bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
if (send_async) {
qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
} else {
qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
}
bytes_sent += TARGET_PAGE_SIZE;
acct_info.norm_pages++;
}
XBZRLE_cache_unlock();
return bytes_sent;
}
/*
* ram_find_and_save_block: Finds a page to send and sends it to f
*
* Returns: The number of bytes written.
* 0 means no dirty pages
*/
static int ram_save_block(QEMUFile *f, bool last_stage)
static int ram_find_and_save_block(QEMUFile *f, bool last_stage)
{
RAMBlock *block = last_seen_block;
ram_addr_t offset = last_offset;
bool complete_round = false;
int bytes_sent = 0;
MemoryRegion *mr;
ram_addr_t current_addr;
if (!block)
block = QTAILQ_FIRST(&ram_list.blocks);
......@@ -594,64 +667,8 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
ram_bulk_stage = false;
}
} else {
int ret;
uint8_t *p;
bool send_async = true;
int cont = (block == last_sent_block) ?
RAM_SAVE_FLAG_CONTINUE : 0;
p = memory_region_get_ram_ptr(mr) + offset;
/* In doubt sent page as normal */
bytes_sent = -1;
ret = ram_control_save_page(f, block->offset,
offset, TARGET_PAGE_SIZE, &bytes_sent);
XBZRLE_cache_lock();
current_addr = block->offset + offset;
if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
if (ret != RAM_SAVE_CONTROL_DELAYED) {
if (bytes_sent > 0) {
acct_info.norm_pages++;
} else if (bytes_sent == 0) {
acct_info.dup_pages++;
}
}
} else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
acct_info.dup_pages++;
bytes_sent = save_block_hdr(f, block, offset, cont,
RAM_SAVE_FLAG_COMPRESS);
qemu_put_byte(f, 0);
bytes_sent++;
/* Must let xbzrle know, otherwise a previous (now 0'd) cached
* page would be stale
*/
xbzrle_cache_zero_page(current_addr);
} else if (!ram_bulk_stage && migrate_use_xbzrle()) {
bytes_sent = save_xbzrle_page(f, &p, current_addr, block,
offset, cont, last_stage);
if (!last_stage) {
/* Can't send this cached data async, since the cache page
* might get updated before it gets to the wire
*/
send_async = false;
}
}
bytes_sent = ram_save_page(f, block, offset, last_stage);
/* XBZRLE overflow or normal page */
if (bytes_sent == -1) {
bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
if (send_async) {
qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
} else {
qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
}
bytes_sent += TARGET_PAGE_SIZE;
acct_info.norm_pages++;
}
XBZRLE_cache_unlock();
/* if page is unmodified, continue to the next */
if (bytes_sent > 0) {
last_sent_block = block;
......@@ -850,7 +867,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
while ((ret = qemu_file_rate_limit(f)) == 0) {
int bytes_sent;
bytes_sent = ram_save_block(f, false);
bytes_sent = ram_find_and_save_block(f, false);
/* no more blocks to sent */
if (bytes_sent == 0) {
break;
......@@ -912,7 +929,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
while (true) {
int bytes_sent;
bytes_sent = ram_save_block(f, true);
bytes_sent = ram_find_and_save_block(f, true);
/* no more blocks to sent */
if (bytes_sent == 0) {
break;
......
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