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ram: Split dirty bitmap by RAMBlock

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Both the ram bitmap and the unsent bitmap are split by RAMBlock.

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

--

Fix compilation when DEBUG_POSTCOPY is enabled (thanks Hailiang)
This commit is contained in:
Juan Quintela 2017-03-22 15:18:04 +01:00
parent e619b14746
commit 6b6712efcc
5 changed files with 116 additions and 175 deletions
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13
include/exec/ram_addr.h
View File

@ -39,6 +39,14 @@ struct RAMBlock {
QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
int fd;
size_t page_size;
/* dirty bitmap used during migration */
unsigned long *bmap;
/* bitmap of pages that haven't been sent even once
* only maintained and used in postcopy at the moment
* where it's used to send the dirtymap at the start
* of the postcopy phase
*/
unsigned long *unsentmap;
};
static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
@ -360,16 +368,15 @@ static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
static inline
uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest,
RAMBlock *rb,
uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
ram_addr_t start,
ram_addr_t length,
uint64_t *real_dirty_pages)
{
ram_addr_t addr;
start = rb->offset + start;
unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
uint64_t num_dirty = 0;
unsigned long *dest = rb->bmap;
/* start address is aligned at the start of a word? */
if (((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) {

3
include/migration/migration.h
View File

@ -266,7 +266,8 @@ uint64_t xbzrle_mig_pages_cache_miss(void);
double xbzrle_mig_cache_miss_rate(void);
void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
void ram_debug_dump_bitmap(unsigned long *todump, bool expected,
unsigned long pages);
/* For outgoing discard bitmap */
int ram_postcopy_send_discard_bitmap(MigrationState *ms);
/* For incoming postcopy discard */

3
include/migration/postcopy-ram.h
View File

@ -43,12 +43,9 @@ int postcopy_ram_prepare_discard(MigrationIncomingState *mis);
/*
* Called at the start of each RAMBlock by the bitmap code.
* 'offset' is the bitmap offset of the named RAMBlock in the migration
* bitmap.
* Returns a new PDS
*/
PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
unsigned long offset,
const char *name);
/*

5
migration/postcopy-ram.c
View File

@ -33,7 +33,6 @@
struct PostcopyDiscardState {
const char *ramblock_name;
uint64_t offset; /* Bitmap entry for the 1st bit of this RAMBlock */
uint16_t cur_entry;
/*
* Start and length of a discard range (bytes)
@ -717,14 +716,12 @@ void *postcopy_get_tmp_page(MigrationIncomingState *mis)
* returns: a new PDS.
*/
PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
unsigned long offset,
const char *name)
{
PostcopyDiscardState *res = g_malloc0(sizeof(PostcopyDiscardState));
if (res) {
res->ramblock_name = name;
res->offset = offset;
}
return res;
@ -745,7 +742,7 @@ void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
{
size_t tp_size = qemu_target_page_size();
/* Convert to byte offsets within the RAM block */
pds->start_list[pds->cur_entry] = (start - pds->offset) * tp_size;
pds->start_list[pds->cur_entry] = start * tp_size;
pds->length_list[pds->cur_entry] = length * tp_size;
trace_postcopy_discard_send_range(pds->ramblock_name, start, length);
pds->cur_entry++;

267
migration/ram.c
View File

@ -138,19 +138,6 @@ out:
return ret;
}
struct RAMBitmap {
struct rcu_head rcu;
/* Main migration bitmap */
unsigned long *bmap;
/* bitmap of pages that haven't been sent even once
* only maintained and used in postcopy at the moment
* where it's used to send the dirtymap at the start
* of the postcopy phase
*/
unsigned long *unsentmap;
};
typedef struct RAMBitmap RAMBitmap;
/*
* An outstanding page request, on the source, having been received
* and queued
@ -220,8 +207,6 @@ struct RAMState {
uint64_t postcopy_requests;
/* protects modification of the bitmap */
QemuMutex bitmap_mutex;
/* Ram Bitmap protected by RCU */
RAMBitmap *ram_bitmap;
/* The RAMBlock used in the last src_page_requests */
RAMBlock *last_req_rb;
/* Queue of outstanding page requests from the destination */
@ -614,22 +599,17 @@ static inline
unsigned long migration_bitmap_find_dirty(RAMState *rs, RAMBlock *rb,
unsigned long start)
{
unsigned long base = rb->offset >> TARGET_PAGE_BITS;
unsigned long nr = base + start;
uint64_t rb_size = rb->used_length;
unsigned long size = base + (rb_size >> TARGET_PAGE_BITS);
unsigned long *bitmap;
unsigned long size = rb->used_length >> TARGET_PAGE_BITS;
unsigned long *bitmap = rb->bmap;
unsigned long next;
bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
if (rs->ram_bulk_stage && nr > base) {
next = nr + 1;
if (rs->ram_bulk_stage && start > 0) {
next = start + 1;
} else {
next = find_next_bit(bitmap, size, nr);
next = find_next_bit(bitmap, size, start);
}
return next - base;
return next;
}
static inline bool migration_bitmap_clear_dirty(RAMState *rs,
@ -637,10 +617,8 @@ static inline bool migration_bitmap_clear_dirty(RAMState *rs,
unsigned long page)
{
bool ret;
unsigned long *bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
unsigned long nr = (rb->offset >> TARGET_PAGE_BITS) + page;
ret = test_and_clear_bit(nr, bitmap);
ret = test_and_clear_bit(page, rb->bmap);
if (ret) {
rs->migration_dirty_pages--;
@ -651,10 +629,8 @@ static inline bool migration_bitmap_clear_dirty(RAMState *rs,
static void migration_bitmap_sync_range(RAMState *rs, RAMBlock *rb,
ram_addr_t start, ram_addr_t length)
{
unsigned long *bitmap;
bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
rs->migration_dirty_pages +=
cpu_physical_memory_sync_dirty_bitmap(bitmap, rb, start, length,
cpu_physical_memory_sync_dirty_bitmap(rb, start, length,
&rs->num_dirty_pages_period);
}
@ -1153,17 +1129,13 @@ static bool get_queued_page(RAMState *rs, PageSearchStatus *pss)
* search already sent it.
*/
if (block) {
unsigned long *bitmap;
unsigned long page;
bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
page = (block->offset + offset) >> TARGET_PAGE_BITS;
dirty = test_bit(page, bitmap);
page = offset >> TARGET_PAGE_BITS;
dirty = test_bit(page, block->bmap);
if (!dirty) {
trace_get_queued_page_not_dirty(block->idstr, (uint64_t)offset,
page,
test_bit(page,
atomic_rcu_read(&rs->ram_bitmap)->unsentmap));
page, test_bit(page, block->unsentmap));
} else {
trace_get_queued_page(block->idstr, (uint64_t)offset, page);
}
@ -1301,16 +1273,13 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss,
/* Check the pages is dirty and if it is send it */
if (migration_bitmap_clear_dirty(rs, pss->block, pss->page)) {
unsigned long *unsentmap;
/*
* If xbzrle is on, stop using the data compression after first
* round of migration even if compression is enabled. In theory,
* xbzrle can do better than compression.
*/
unsigned long page =
(pss->block->offset >> TARGET_PAGE_BITS) + pss->page;
if (migrate_use_compression()
&& (rs->ram_bulk_stage || !migrate_use_xbzrle())) {
if (migrate_use_compression() &&
(rs->ram_bulk_stage || !migrate_use_xbzrle())) {
res = ram_save_compressed_page(rs, pss, last_stage);
} else {
res = ram_save_page(rs, pss, last_stage);
@ -1319,9 +1288,8 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss,
if (res < 0) {
return res;
}
unsentmap = atomic_rcu_read(&rs->ram_bitmap)->unsentmap;
if (unsentmap) {
clear_bit(page, unsentmap);
if (pss->block->unsentmap) {
clear_bit(pss->page, pss->block->unsentmap);
}
}
@ -1451,25 +1419,20 @@ void free_xbzrle_decoded_buf(void)
xbzrle_decoded_buf = NULL;
}
static void migration_bitmap_free(RAMBitmap *bmap)
{
g_free(bmap->bmap);
g_free(bmap->unsentmap);
g_free(bmap);
}
static void ram_migration_cleanup(void *opaque)
{
RAMState *rs = opaque;
RAMBlock *block;
/* caller have hold iothread lock or is in a bh, so there is
* no writing race against this migration_bitmap
*/
RAMBitmap *bitmap = rs->ram_bitmap;
atomic_rcu_set(&rs->ram_bitmap, NULL);
if (bitmap) {
memory_global_dirty_log_stop();
call_rcu(bitmap, migration_bitmap_free, rcu);
memory_global_dirty_log_stop();
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
g_free(block->bmap);
block->bmap = NULL;
g_free(block->unsentmap);
block->unsentmap = NULL;
}
XBZRLE_cache_lock();
@ -1501,27 +1464,22 @@ static void ram_state_reset(RAMState *rs)
* of; it won't bother printing lines that are all this value.
* If 'todump' is null the migration bitmap is dumped.
*/
void ram_debug_dump_bitmap(unsigned long *todump, bool expected)
void ram_debug_dump_bitmap(unsigned long *todump, bool expected,
unsigned long pages)
{
unsigned long ram_pages = last_ram_page();
RAMState *rs = &ram_state;
int64_t cur;
int64_t linelen = 128;
char linebuf[129];
if (!todump) {
todump = atomic_rcu_read(&rs->ram_bitmap)->bmap;
}
for (cur = 0; cur < ram_pages; cur += linelen) {
for (cur = 0; cur < pages; cur += linelen) {
int64_t curb;
bool found = false;
/*
* Last line; catch the case where the line length
* is longer than remaining ram
*/
if (cur + linelen > ram_pages) {
linelen = ram_pages - cur;
if (cur + linelen > pages) {
linelen = pages - cur;
}
for (curb = 0; curb < linelen; curb++) {
bool thisbit = test_bit(cur + curb, todump);
@ -1539,14 +1497,12 @@ void ram_debug_dump_bitmap(unsigned long *todump, bool expected)
void ram_postcopy_migrated_memory_release(MigrationState *ms)
{
RAMState *rs = &ram_state;
struct RAMBlock *block;
unsigned long *bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
unsigned long first = block->offset >> TARGET_PAGE_BITS;
unsigned long range = first + (block->used_length >> TARGET_PAGE_BITS);
unsigned long run_start = find_next_zero_bit(bitmap, range, first);
unsigned long *bitmap = block->bmap;
unsigned long range = block->used_length >> TARGET_PAGE_BITS;
unsigned long run_start = find_next_zero_bit(bitmap, range, 0);
while (run_start < range) {
unsigned long run_end = find_next_bit(bitmap, range, run_start + 1);
@ -1573,16 +1529,13 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms)
*/
static int postcopy_send_discard_bm_ram(MigrationState *ms,
PostcopyDiscardState *pds,
unsigned long start,
unsigned long length)
RAMBlock *block)
{
RAMState *rs = &ram_state;
unsigned long end = start + length; /* one after the end */
unsigned long end = block->used_length >> TARGET_PAGE_BITS;
unsigned long current;
unsigned long *unsentmap;
unsigned long *unsentmap = block->unsentmap;
unsentmap = atomic_rcu_read(&rs->ram_bitmap)->unsentmap;
for (current = start; current < end; ) {
for (current = 0; current < end; ) {
unsigned long one = find_next_bit(unsentmap, end, current);
if (one <= end) {
@ -1625,18 +1578,15 @@ static int postcopy_each_ram_send_discard(MigrationState *ms)
int ret;
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
unsigned long first = block->offset >> TARGET_PAGE_BITS;
PostcopyDiscardState *pds = postcopy_discard_send_init(ms,
first,
block->idstr);
PostcopyDiscardState *pds =
postcopy_discard_send_init(ms, block->idstr);
/*
* Postcopy sends chunks of bitmap over the wire, but it
* just needs indexes at this point, avoids it having
* target page specific code.
*/
ret = postcopy_send_discard_bm_ram(ms, pds, first,
block->used_length >> TARGET_PAGE_BITS);
ret = postcopy_send_discard_bm_ram(ms, pds, block);
postcopy_discard_send_finish(ms, pds);
if (ret) {
return ret;
@ -1667,12 +1617,10 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
PostcopyDiscardState *pds)
{
RAMState *rs = &ram_state;
unsigned long *bitmap;
unsigned long *unsentmap;
unsigned long *bitmap = block->bmap;
unsigned long *unsentmap = block->unsentmap;
unsigned int host_ratio = block->page_size / TARGET_PAGE_SIZE;
unsigned long first = block->offset >> TARGET_PAGE_BITS;
unsigned long len = block->used_length >> TARGET_PAGE_BITS;
unsigned long last = first + (len - 1);
unsigned long pages = block->used_length >> TARGET_PAGE_BITS;
unsigned long run_start;
if (block->page_size == TARGET_PAGE_SIZE) {
@ -1680,18 +1628,15 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
return;
}
bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
unsentmap = atomic_rcu_read(&rs->ram_bitmap)->unsentmap;
if (unsent_pass) {
/* Find a sent page */
run_start = find_next_zero_bit(unsentmap, last + 1, first);
run_start = find_next_zero_bit(unsentmap, pages, 0);
} else {
/* Find a dirty page */
run_start = find_next_bit(bitmap, last + 1, first);
run_start = find_next_bit(bitmap, pages, 0);
}
while (run_start <= last) {
while (run_start < pages) {
bool do_fixup = false;
unsigned long fixup_start_addr;
unsigned long host_offset;
@ -1711,9 +1656,9 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
/* Find the end of this run */
unsigned long run_end;
if (unsent_pass) {
run_end = find_next_bit(unsentmap, last + 1, run_start + 1);
run_end = find_next_bit(unsentmap, pages, run_start + 1);
} else {
run_end = find_next_zero_bit(bitmap, last + 1, run_start + 1);
run_end = find_next_zero_bit(bitmap, pages, run_start + 1);
}
/*
* If the end isn't at the start of a host page, then the
@ -1770,11 +1715,10 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
if (unsent_pass) {
/* Find the next sent page for the next iteration */
run_start = find_next_zero_bit(unsentmap, last + 1,
run_start);
run_start = find_next_zero_bit(unsentmap, pages, run_start);
} else {
/* Find the next dirty page for the next iteration */
run_start = find_next_bit(bitmap, last + 1, run_start);
run_start = find_next_bit(bitmap, pages, run_start);
}
}
}
@ -1791,34 +1735,22 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
* Returns zero on success
*
* @ms: current migration state
* @block: block we want to work with
*/
static int postcopy_chunk_hostpages(MigrationState *ms)
static int postcopy_chunk_hostpages(MigrationState *ms, RAMBlock *block)
{
RAMState *rs = &ram_state;
struct RAMBlock *block;
PostcopyDiscardState *pds =
postcopy_discard_send_init(ms, block->idstr);
/* Easiest way to make sure we don't resume in the middle of a host-page */
rs->last_seen_block = NULL;
rs->last_sent_block = NULL;
rs->last_page = 0;
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
unsigned long first = block->offset >> TARGET_PAGE_BITS;
PostcopyDiscardState *pds =
postcopy_discard_send_init(ms, first, block->idstr);
/* First pass: Discard all partially sent host pages */
postcopy_chunk_hostpages_pass(ms, true, block, pds);
/*
* Second pass: Ensure that all partially dirty host pages are made
* fully dirty.
*/
postcopy_chunk_hostpages_pass(ms, false, block, pds);
postcopy_discard_send_finish(ms, pds);
} /* ram_list loop */
/* First pass: Discard all partially sent host pages */
postcopy_chunk_hostpages_pass(ms, true, block, pds);
/*
* Second pass: Ensure that all partially dirty host pages are made
* fully dirty.
*/
postcopy_chunk_hostpages_pass(ms, false, block, pds);
postcopy_discard_send_finish(ms, pds);
return 0;
}
@ -1840,43 +1772,49 @@ static int postcopy_chunk_hostpages(MigrationState *ms)
int ram_postcopy_send_discard_bitmap(MigrationState *ms)
{
RAMState *rs = &ram_state;
RAMBlock *block;
int ret;
unsigned long *bitmap, *unsentmap;
rcu_read_lock();
/* This should be our last sync, the src is now paused */
migration_bitmap_sync(rs);
unsentmap = atomic_rcu_read(&rs->ram_bitmap)->unsentmap;
if (!unsentmap) {
/* We don't have a safe way to resize the sentmap, so
* if the bitmap was resized it will be NULL at this
* point.
/* Easiest way to make sure we don't resume in the middle of a host-page */
rs->last_seen_block = NULL;
rs->last_sent_block = NULL;
rs->last_page = 0;
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
unsigned long pages = block->used_length >> TARGET_PAGE_BITS;
unsigned long *bitmap = block->bmap;
unsigned long *unsentmap = block->unsentmap;
if (!unsentmap) {
/* We don't have a safe way to resize the sentmap, so
* if the bitmap was resized it will be NULL at this
* point.
*/
error_report("migration ram resized during precopy phase");
rcu_read_unlock();
return -EINVAL;
}
/* Deal with TPS != HPS and huge pages */
ret = postcopy_chunk_hostpages(ms, block);
if (ret) {
rcu_read_unlock();
return ret;
}
/*
* Update the unsentmap to be unsentmap = unsentmap | dirty
*/
error_report("migration ram resized during precopy phase");
rcu_read_unlock();
return -EINVAL;
}
/* Deal with TPS != HPS and huge pages */
ret = postcopy_chunk_hostpages(ms);
if (ret) {
rcu_read_unlock();
return ret;
}
/*
* Update the unsentmap to be unsentmap = unsentmap | dirty
*/
bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
bitmap_or(unsentmap, unsentmap, bitmap, last_ram_page());
trace_ram_postcopy_send_discard_bitmap();
bitmap_or(unsentmap, unsentmap, bitmap, pages);
#ifdef DEBUG_POSTCOPY
ram_debug_dump_bitmap(unsentmap, true);
ram_debug_dump_bitmap(unsentmap, true, pages);
#endif
}
trace_ram_postcopy_send_discard_bitmap();
ret = postcopy_each_ram_send_discard(ms);
rcu_read_unlock();
@ -1918,8 +1856,6 @@ err:
static int ram_state_init(RAMState *rs)
{
unsigned long ram_bitmap_pages;
memset(rs, 0, sizeof(*rs));
qemu_mutex_init(&rs->bitmap_mutex);
qemu_mutex_init(&rs->src_page_req_mutex);
@ -1961,16 +1897,19 @@ static int ram_state_init(RAMState *rs)
rcu_read_lock();
ram_state_reset(rs);
rs->ram_bitmap = g_new0(RAMBitmap, 1);
/* Skip setting bitmap if there is no RAM */
if (ram_bytes_total()) {
ram_bitmap_pages = last_ram_page();
rs->ram_bitmap->bmap = bitmap_new(ram_bitmap_pages);
bitmap_set(rs->ram_bitmap->bmap, 0, ram_bitmap_pages);
RAMBlock *block;
if (migrate_postcopy_ram()) {
rs->ram_bitmap->unsentmap = bitmap_new(ram_bitmap_pages);
bitmap_set(rs->ram_bitmap->unsentmap, 0, ram_bitmap_pages);
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
unsigned long pages = block->max_length >> TARGET_PAGE_BITS;
block->bmap = bitmap_new(pages);
bitmap_set(block->bmap, 0, pages);
if (migrate_postcopy_ram()) {
block->unsentmap = bitmap_new(pages);
bitmap_set(block->unsentmap, 0, pages);
}
}
}