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migration: We only need last_stage in two places
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We only need last_stage in two places and we are passing it all
around.  Just add a field to RAMState that passes it.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>

---

Repeat subject (philmd suggestion)
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Juan Quintela committed Jan 27, 2022
1 parent e4eee5f commit dc081fa
Showing 1 changed file with 18 additions and 23 deletions.
41 changes: 18 additions & 23 deletions migration/ram.c
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Expand Up @@ -325,7 +325,8 @@ struct RAMState {
uint64_t xbzrle_bytes_prev;
/* Start using XBZRLE (e.g., after the first round). */
bool xbzrle_enabled;

/* Are we on the last stage of migration */
bool last_stage;
/* compression statistics since the beginning of the period */
/* amount of count that no free thread to compress data */
uint64_t compress_thread_busy_prev;
Expand Down Expand Up @@ -683,19 +684,18 @@ static void xbzrle_cache_zero_page(RAMState *rs, ram_addr_t current_addr)
* @current_addr: addr of the page
* @block: block that contains the page we want to send
* @offset: offset inside the block for the page
* @last_stage: if we are at the completion stage
*/
static int save_xbzrle_page(RAMState *rs, uint8_t **current_data,
ram_addr_t current_addr, RAMBlock *block,
ram_addr_t offset, bool last_stage)
ram_addr_t offset)
{
int encoded_len = 0, bytes_xbzrle;
uint8_t *prev_cached_page;

if (!cache_is_cached(XBZRLE.cache, current_addr,
ram_counters.dirty_sync_count)) {
xbzrle_counters.cache_miss++;
if (!last_stage) {
if (!rs->last_stage) {
if (cache_insert(XBZRLE.cache, current_addr, *current_data,
ram_counters.dirty_sync_count) == -1) {
return -1;
Expand Down Expand Up @@ -734,7 +734,7 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data,
* Update the cache contents, so that it corresponds to the data
* sent, in all cases except where we skip the page.
*/
if (!last_stage && encoded_len != 0) {
if (!rs->last_stage && encoded_len != 0) {
memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);
/*
* In the case where we couldn't compress, ensure that the caller
Expand Down Expand Up @@ -1290,9 +1290,8 @@ static int save_normal_page(RAMState *rs, RAMBlock *block, ram_addr_t offset,
* @rs: current RAM state
* @block: block that contains the page we want to send
* @offset: offset inside the block for the page
* @last_stage: if we are at the completion stage
*/
static int ram_save_page(RAMState *rs, PageSearchStatus *pss, bool last_stage)
static int ram_save_page(RAMState *rs, PageSearchStatus *pss)
{
int pages = -1;
uint8_t *p;
Expand All @@ -1307,8 +1306,8 @@ static int ram_save_page(RAMState *rs, PageSearchStatus *pss, bool last_stage)
XBZRLE_cache_lock();
if (rs->xbzrle_enabled && !migration_in_postcopy()) {
pages = save_xbzrle_page(rs, &p, current_addr, block,
offset, last_stage);
if (!last_stage) {
offset);
if (!rs->last_stage) {
/* Can't send this cached data async, since the cache page
* might get updated before it gets to the wire
*/
Expand Down Expand Up @@ -2129,10 +2128,8 @@ static bool save_compress_page(RAMState *rs, RAMBlock *block, ram_addr_t offset)
*
* @rs: current RAM state
* @pss: data about the page we want to send
* @last_stage: if we are at the completion stage
*/
static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss,
bool last_stage)
static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss)
{
RAMBlock *block = pss->block;
ram_addr_t offset = ((ram_addr_t)pss->page) << TARGET_PAGE_BITS;
Expand Down Expand Up @@ -2171,7 +2168,7 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss,
return ram_save_multifd_page(rs, block, offset);
}

return ram_save_page(rs, pss, last_stage);
return ram_save_page(rs, pss);
}

/**
Expand All @@ -2190,10 +2187,8 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss,
* @rs: current RAM state
* @ms: current migration state
* @pss: data about the page we want to send
* @last_stage: if we are at the completion stage
*/
static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss,
bool last_stage)
static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss)
{
int tmppages, pages = 0;
size_t pagesize_bits =
Expand All @@ -2211,7 +2206,7 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss,
do {
/* Check the pages is dirty and if it is send it */
if (migration_bitmap_clear_dirty(rs, pss->block, pss->page)) {
tmppages = ram_save_target_page(rs, pss, last_stage);
tmppages = ram_save_target_page(rs, pss);
if (tmppages < 0) {
return tmppages;
}
Expand Down Expand Up @@ -2245,13 +2240,11 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss,
* or negative on error
*
* @rs: current RAM state
* @last_stage: if we are at the completion stage
*
* On systems where host-page-size > target-page-size it will send all the
* pages in a host page that are dirty.
*/

static int ram_find_and_save_block(RAMState *rs, bool last_stage)
static int ram_find_and_save_block(RAMState *rs)
{
PageSearchStatus pss;
int pages = 0;
Expand Down Expand Up @@ -2280,7 +2273,7 @@ static int ram_find_and_save_block(RAMState *rs, bool last_stage)
}

if (found) {
pages = ram_save_host_page(rs, &pss, last_stage);
pages = ram_save_host_page(rs, &pss);
}
} while (!pages && again);

Expand Down Expand Up @@ -3080,7 +3073,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
break;
}

pages = ram_find_and_save_block(rs, false);
pages = ram_find_and_save_block(rs);
/* no more pages to sent */
if (pages == 0) {
done = 1;
Expand Down Expand Up @@ -3160,6 +3153,8 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
RAMState *rs = *temp;
int ret = 0;

rs->last_stage = !migration_in_colo_state();

WITH_RCU_READ_LOCK_GUARD() {
if (!migration_in_postcopy()) {
migration_bitmap_sync_precopy(rs);
Expand All @@ -3173,7 +3168,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
while (true) {
int pages;

pages = ram_find_and_save_block(rs, !migration_in_colo_state());
pages = ram_find_and_save_block(rs);
/* no more blocks to sent */
if (pages == 0) {
break;
Expand Down

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