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migration: Remove non-multifd compression

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The 'compress' migration capability enables the old compression code
which has shown issues over the years and is thought to be less stable
and tested than the more recent multifd-based compression. The old
compression code has been deprecated in 8.2 and now is time to remove
it.

Deprecation commit 864128df46 ("migration: Deprecate old compression
method").

Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
This commit is contained in:
Fabiano Rosas 2024-04-30 11:27:36 -03:00
parent eef0bae3a7
commit 0222111a22
16 changed files with 64 additions and 1368 deletions
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154
migration/ram.c
View file

@ -33,7 +33,6 @@
#include "qemu/madvise.h"
#include "qemu/main-loop.h"
#include "xbzrle.h"
#include "ram-compress.h"
#include "ram.h"
#include "migration.h"
#include "migration-stats.h"
@ -77,9 +76,10 @@
* worked for pages that were filled with the same char. We switched
* it to only search for the zero value. And to avoid confusion with
* RAM_SAVE_FLAG_COMPRESS_PAGE just rename it.
*/
/*
* RAM_SAVE_FLAG_FULL was obsoleted in 2009, it can be reused now
*
* RAM_SAVE_FLAG_FULL was obsoleted in 2009.
*
* RAM_SAVE_FLAG_COMPRESS_PAGE (0x100) was removed in QEMU 9.1.
*/
#define RAM_SAVE_FLAG_FULL 0x01
#define RAM_SAVE_FLAG_ZERO 0x02
@ -89,7 +89,6 @@
#define RAM_SAVE_FLAG_CONTINUE 0x20
#define RAM_SAVE_FLAG_XBZRLE 0x40
/* 0x80 is reserved in rdma.h for RAM_SAVE_FLAG_HOOK */
#define RAM_SAVE_FLAG_COMPRESS_PAGE 0x100
#define RAM_SAVE_FLAG_MULTIFD_FLUSH 0x200
/* We can't use any flag that is bigger than 0x200 */
@ -690,8 +689,7 @@ static int save_xbzrle_page(RAMState *rs, PageSearchStatus *pss,
qemu_put_buffer(file, XBZRLE.encoded_buf, encoded_len);
bytes_xbzrle += encoded_len + 1 + 2;
/*
* Like compressed_size (please see update_compress_thread_counts),
* the xbzrle encoded bytes don't count the 8 byte header with
* The xbzrle encoded bytes don't count the 8 byte header with
* RAM_SAVE_FLAG_CONTINUE.
*/
xbzrle_counters.bytes += bytes_xbzrle - 8;
@ -949,7 +947,7 @@ uint64_t ram_get_total_transferred_pages(void)
{
return stat64_get(&mig_stats.normal_pages) +
stat64_get(&mig_stats.zero_pages) +
compress_ram_pages() + xbzrle_counters.pages;
xbzrle_counters.pages;
}
static void migration_update_rates(RAMState *rs, int64_t end_time)
@ -982,7 +980,6 @@ static void migration_update_rates(RAMState *rs, int64_t end_time)
rs->xbzrle_pages_prev = xbzrle_counters.pages;
rs->xbzrle_bytes_prev = xbzrle_counters.bytes;
}
compress_update_rates(page_count);
}
/*
@ -1288,41 +1285,6 @@ static int ram_save_multifd_page(RAMBlock *block, ram_addr_t offset)
return 1;
}
int compress_send_queued_data(CompressParam *param)
{
PageSearchStatus *pss = &ram_state->pss[RAM_CHANNEL_PRECOPY];
MigrationState *ms = migrate_get_current();
QEMUFile *file = ms->to_dst_file;
int len = 0;
RAMBlock *block = param->block;
ram_addr_t offset = param->offset;
if (param->result == RES_NONE) {
return 0;
}
assert(block == pss->last_sent_block);
if (param->result == RES_ZEROPAGE) {
assert(qemu_file_buffer_empty(param->file));
len += save_page_header(pss, file, block, offset | RAM_SAVE_FLAG_ZERO);
qemu_put_byte(file, 0);
len += 1;
ram_release_page(block->idstr, offset);
} else if (param->result == RES_COMPRESS) {
assert(!qemu_file_buffer_empty(param->file));
len += save_page_header(pss, file, block,
offset | RAM_SAVE_FLAG_COMPRESS_PAGE);
len += qemu_put_qemu_file(file, param->file);
} else {
abort();
}
update_compress_thread_counts(param, len);
return len;
}
#define PAGE_ALL_CLEAN 0
#define PAGE_TRY_AGAIN 1
@ -1374,16 +1336,6 @@ static int find_dirty_block(RAMState *rs, PageSearchStatus *pss)
qemu_fflush(f);
}
}
/*
* If memory migration starts over, we will meet a dirtied page
* which may still exists in compression threads's ring, so we
* should flush the compressed data to make sure the new page
* is not overwritten by the old one in the destination.
*
* Also If xbzrle is on, stop using the data compression at this
* point. In theory, xbzrle can do better than compression.
*/
compress_flush_data();
/* Hit the end of the list */
pss->block = QLIST_FIRST_RCU(&ram_list.blocks);
@ -2034,37 +1986,6 @@ int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len,
return 0;
}
/*
* try to compress the page before posting it out, return true if the page
* has been properly handled by compression, otherwise needs other
* paths to handle it
*/
static bool save_compress_page(RAMState *rs, PageSearchStatus *pss,
ram_addr_t offset)
{
if (!migrate_compress()) {
return false;
}
/*
* When starting the process of a new block, the first page of
* the block should be sent out before other pages in the same
* block, and all the pages in last block should have been sent
* out, keeping this order is important, because the 'cont' flag
* is used to avoid resending the block name.
*
* We post the fist page as normal page as compression will take
* much CPU resource.
*/
if (pss->block != pss->last_sent_block) {
compress_flush_data();
return false;
}
return compress_page_with_multi_thread(pss->block, offset,
compress_send_queued_data);
}
/**
* ram_save_target_page_legacy: save one target page
*
@ -2082,10 +2003,6 @@ static int ram_save_target_page_legacy(RAMState *rs, PageSearchStatus *pss)
return res;
}
if (save_compress_page(rs, pss, offset)) {
return 1;
}
if (save_zero_page(rs, pss, offset)) {
return 1;
}
@ -2470,7 +2387,6 @@ static void ram_save_cleanup(void *opaque)
ram_bitmaps_destroy();
xbzrle_cleanup();
compress_threads_save_cleanup();
ram_state_cleanup(rsp);
g_free(migration_ops);
migration_ops = NULL;
@ -3089,15 +3005,9 @@ static int ram_save_setup(QEMUFile *f, void *opaque, Error **errp)
RAMBlock *block;
int ret, max_hg_page_size;
if (compress_threads_save_setup()) {
error_setg(errp, "%s: failed to start compress threads", __func__);
return -1;
}
/* migration has already setup the bitmap, reuse it. */
if (!migration_in_colo_state()) {
if (ram_init_all(rsp, errp) != 0) {
compress_threads_save_cleanup();
return -1;
}
}
@ -3268,14 +3178,6 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
rs->target_page_count += pages;
/*
* During postcopy, it is necessary to make sure one whole host
* page is sent in one chunk.
*/
if (migrate_postcopy_ram()) {
compress_flush_data();
}
/*
* we want to check in the 1st loop, just in case it was the 1st
* time and we had to sync the dirty bitmap.
@ -3374,8 +3276,6 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
}
qemu_mutex_unlock(&rs->bitmap_mutex);
compress_flush_data();
ret = rdma_registration_stop(f, RAM_CONTROL_FINISH);
if (ret < 0) {
qemu_file_set_error(f, ret);
@ -3789,7 +3689,6 @@ int ram_load_postcopy(QEMUFile *f, int channel)
void *place_source = NULL;
RAMBlock *block = NULL;
uint8_t ch;
int len;
addr = qemu_get_be64(f);
@ -3806,8 +3705,7 @@ int ram_load_postcopy(QEMUFile *f, int channel)
addr &= TARGET_PAGE_MASK;
trace_ram_load_postcopy_loop(channel, (uint64_t)addr, flags);
if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE |
RAM_SAVE_FLAG_COMPRESS_PAGE)) {
if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE)) {
block = ram_block_from_stream(mis, f, flags, channel);
if (!block) {
ret = -EINVAL;
@ -3902,16 +3800,6 @@ int ram_load_postcopy(QEMUFile *f, int channel)
TARGET_PAGE_SIZE);
}
break;
case RAM_SAVE_FLAG_COMPRESS_PAGE:
tmp_page->all_zero = false;
len = qemu_get_be32(f);
if (len < 0 || len > compressBound(TARGET_PAGE_SIZE)) {
error_report("Invalid compressed data length: %d", len);
ret = -EINVAL;
break;
}
decompress_data_with_multi_threads(f, page_buffer, len);
break;
case RAM_SAVE_FLAG_MULTIFD_FLUSH:
multifd_recv_sync_main();
break;
@ -3929,11 +3817,6 @@ int ram_load_postcopy(QEMUFile *f, int channel)
break;
}
/* Got the whole host page, wait for decompress before placing. */
if (place_needed) {
ret |= wait_for_decompress_done();
}
/* Detect for any possible file errors */
if (!ret && qemu_file_get_error(f)) {
ret = qemu_file_get_error(f);
@ -4238,11 +4121,7 @@ static int parse_ramblocks(QEMUFile *f, ram_addr_t total_ram_bytes)
static int ram_load_precopy(QEMUFile *f)
{
MigrationIncomingState *mis = migration_incoming_get_current();
int flags = 0, ret = 0, invalid_flags = 0, len = 0, i = 0;
if (!migrate_compress()) {
invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE;
}
int flags = 0, ret = 0, invalid_flags = 0, i = 0;
if (migrate_mapped_ram()) {
invalid_flags |= (RAM_SAVE_FLAG_HOOK | RAM_SAVE_FLAG_MULTIFD_FLUSH |
@ -4279,16 +4158,12 @@ static int ram_load_precopy(QEMUFile *f)
if (flags & invalid_flags) {
error_report("Unexpected RAM flags: %d", flags & invalid_flags);
if (flags & invalid_flags & RAM_SAVE_FLAG_COMPRESS_PAGE) {
error_report("Received an unexpected compressed page");
}
ret = -EINVAL;
break;
}
if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE |
RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) {
RAM_SAVE_FLAG_XBZRLE)) {
RAMBlock *block = ram_block_from_stream(mis, f, flags,
RAM_CHANNEL_PRECOPY);
@ -4357,16 +4232,6 @@ static int ram_load_precopy(QEMUFile *f)
qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
break;
case RAM_SAVE_FLAG_COMPRESS_PAGE:
len = qemu_get_be32(f);
if (len < 0 || len > compressBound(TARGET_PAGE_SIZE)) {
error_report("Invalid compressed data length: %d", len);
ret = -EINVAL;
break;
}
decompress_data_with_multi_threads(f, host, len);
break;
case RAM_SAVE_FLAG_XBZRLE:
if (load_xbzrle(f, addr, host) < 0) {
error_report("Failed to decompress XBZRLE page at "
@ -4408,7 +4273,6 @@ static int ram_load_precopy(QEMUFile *f)
}
}
ret |= wait_for_decompress_done();
return ret;
}