motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-04 16:23:55 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

migration/multifd: Implement zero page transmission on the multifd thread.

Browse source 
1. Add zero_pages field in MultiFDPacket_t.
2. Implements the zero page detection and handling on the multifd
threads for non-compression, zlib and zstd compression backends.
3. Added a new value 'multifd' in ZeroPageDetection enumeration.
4. Adds zero page counters and updates multifd send/receive tracing
format to track the newly added counters.

Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240311180015.3359271-5-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>
This commit is contained in:
Hao Xiang 2024-03-11 18:00:12 +00:00 • committed by Peter Xu
parent 5fdbb1dfcc
commit 303e6f54f9
10 changed files with 228 additions and 32 deletions
Download patch file Download diff file Expand all files Collapse all files

90
migration/multifd.c
View file

@ -11,6 +11,7 @@
*/
#include "qemu/osdep.h"
#include "qemu/cutils.h"
#include "qemu/rcu.h"
#include "exec/target_page.h"
#include "sysemu/sysemu.h"
@ -111,12 +112,17 @@ void multifd_send_channel_created(void)
static void multifd_set_file_bitmap(MultiFDSendParams *p)
{
MultiFDPages_t *pages = p->pages;
uint32_t zero_num = p->pages->num - p->pages->normal_num;
assert(pages->block);
for (int i = 0; i < p->pages->num; i++) {
for (int i = 0; i < p->pages->normal_num; i++) {
ramblock_set_file_bmap_atomic(pages->block, pages->offset[i], true);
}
for (int i = p->pages->num; i < zero_num; i++) {
ramblock_set_file_bmap_atomic(pages->block, pages->offset[i], false);
}
}
/* Multifd without compression */
@ -153,13 +159,13 @@ static void multifd_send_prepare_iovs(MultiFDSendParams *p)
{
MultiFDPages_t *pages = p->pages;
for (int i = 0; i < pages->num; i++) {
for (int i = 0; i < pages->normal_num; i++) {
p->iov[p->iovs_num].iov_base = pages->block->host + pages->offset[i];
p->iov[p->iovs_num].iov_len = p->page_size;
p->iovs_num++;
}
p->next_packet_size = pages->num * p->page_size;
p->next_packet_size = pages->normal_num * p->page_size;
}
/**
@ -178,6 +184,8 @@ static int nocomp_send_prepare(MultiFDSendParams *p, Error **errp)
bool use_zero_copy_send = migrate_zero_copy_send();
int ret;
multifd_send_zero_page_detect(p);
if (!multifd_use_packets()) {
multifd_send_prepare_iovs(p);
multifd_set_file_bitmap(p);
@ -261,6 +269,13 @@ static int nocomp_recv(MultiFDRecvParams *p, Error **errp)
p->id, flags, MULTIFD_FLAG_NOCOMP);
return -1;
}
multifd_recv_zero_page_process(p);
if (!p->normal_num) {
return 0;
}
for (int i = 0; i < p->normal_num; i++) {
p->iov[i].iov_base = p->host + p->normal[i];
p->iov[i].iov_len = p->page_size;
@ -295,6 +310,7 @@ static void multifd_pages_reset(MultiFDPages_t *pages)
* overwritten later when reused.
*/
pages->num = 0;
pages->normal_num = 0;
pages->block = NULL;
}
@ -386,11 +402,13 @@ void multifd_send_fill_packet(MultiFDSendParams *p)
MultiFDPacket_t *packet = p->packet;
MultiFDPages_t *pages = p->pages;
uint64_t packet_num;
uint32_t zero_num = pages->num - pages->normal_num;
int i;
packet->flags = cpu_to_be32(p->flags);
packet->pages_alloc = cpu_to_be32(p->pages->allocated);
packet->normal_pages = cpu_to_be32(pages->num);
packet->normal_pages = cpu_to_be32(pages->normal_num);
packet->zero_pages = cpu_to_be32(zero_num);
packet->next_packet_size = cpu_to_be32(p->next_packet_size);
packet_num = qatomic_fetch_inc(&multifd_send_state->packet_num);
@ -408,10 +426,11 @@ void multifd_send_fill_packet(MultiFDSendParams *p)
}
p->packets_sent++;
p->total_normal_pages += pages->num;
p->total_normal_pages += pages->normal_num;
p->total_zero_pages += zero_num;
trace_multifd_send(p->id, packet_num, pages->num, p->flags,
p->next_packet_size);
trace_multifd_send(p->id, packet_num, pages->normal_num, zero_num,
p->flags, p->next_packet_size);
}
static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
@ -452,20 +471,29 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
p->normal_num = be32_to_cpu(packet->normal_pages);
if (p->normal_num > packet->pages_alloc) {
error_setg(errp, "multifd: received packet "
"with %u pages and expected maximum pages are %u",
"with %u normal pages and expected maximum pages are %u",
p->normal_num, packet->pages_alloc) ;
return -1;
}
p->zero_num = be32_to_cpu(packet->zero_pages);
if (p->zero_num > packet->pages_alloc - p->normal_num) {
error_setg(errp, "multifd: received packet "
"with %u zero pages and expected maximum zero pages are %u",
p->zero_num, packet->pages_alloc - p->normal_num) ;
return -1;
}
p->next_packet_size = be32_to_cpu(packet->next_packet_size);
p->packet_num = be64_to_cpu(packet->packet_num);
p->packets_recved++;
p->total_normal_pages += p->normal_num;
p->total_zero_pages += p->zero_num;
trace_multifd_recv(p->id, p->packet_num, p->normal_num, p->flags,
p->next_packet_size);
trace_multifd_recv(p->id, p->packet_num, p->normal_num, p->zero_num,
p->flags, p->next_packet_size);
if (p->normal_num == 0) {
if (p->normal_num == 0 && p->zero_num == 0) {
return 0;
}
@ -491,6 +519,18 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
p->normal[i] = offset;
}
for (i = 0; i < p->zero_num; i++) {
uint64_t offset = be64_to_cpu(packet->offset[p->normal_num + i]);
if (offset > (p->block->used_length - p->page_size)) {
error_setg(errp, "multifd: offset too long %" PRIu64
" (max " RAM_ADDR_FMT ")",
offset, p->block->used_length);
return -1;
}
p->zero[i] = offset;
}
return 0;
}
@ -918,6 +958,8 @@ static void *multifd_send_thread(void *opaque)
stat64_add(&mig_stats.multifd_bytes,
p->next_packet_size + p->packet_len);
stat64_add(&mig_stats.normal_pages, pages->normal_num);
stat64_add(&mig_stats.zero_pages, pages->num - pages->normal_num);
multifd_pages_reset(p->pages);
p->next_packet_size = 0;
@ -965,7 +1007,8 @@ out:
rcu_unregister_thread();
migration_threads_remove(thread);
trace_multifd_send_thread_end(p->id, p->packets_sent, p->total_normal_pages);
trace_multifd_send_thread_end(p->id, p->packets_sent, p->total_normal_pages,
p->total_zero_pages);
return NULL;
}
@ -1316,6 +1359,8 @@ static void multifd_recv_cleanup_channel(MultiFDRecvParams *p)
p->iov = NULL;
g_free(p->normal);
p->normal = NULL;
g_free(p->zero);
p->zero = NULL;
multifd_recv_state->ops->recv_cleanup(p);
}
@ -1449,7 +1494,7 @@ static void *multifd_recv_thread(void *opaque)
flags = p->flags;
/* recv methods don't know how to handle the SYNC flag */
p->flags &= ~MULTIFD_FLAG_SYNC;
has_data = !!p->normal_num;
has_data = p->normal_num || p->zero_num;
qemu_mutex_unlock(&p->mutex);
} else {
/*
@ -1507,7 +1552,9 @@ static void *multifd_recv_thread(void *opaque)
}
rcu_unregister_thread();
trace_multifd_recv_thread_end(p->id, p->packets_recved, p->total_normal_pages);
trace_multifd_recv_thread_end(p->id, p->packets_recved,
p->total_normal_pages,
p->total_zero_pages);
return NULL;
}
@ -1559,6 +1606,7 @@ int multifd_recv_setup(Error **errp)
p->name = g_strdup_printf("multifdrecv_%d", i);
p->iov = g_new0(struct iovec, page_count);
p->normal = g_new0(ram_addr_t, page_count);
p->zero = g_new0(ram_addr_t, page_count);
p->page_count = page_count;
p->page_size = qemu_target_page_size();
}
@ -1633,3 +1681,17 @@ void multifd_recv_new_channel(QIOChannel *ioc, Error **errp)
QEMU_THREAD_JOINABLE);
qatomic_inc(&multifd_recv_state->count);
}
bool multifd_send_prepare_common(MultiFDSendParams *p)
{
multifd_send_zero_page_detect(p);
if (!p->pages->normal_num) {
p->next_packet_size = 0;
return false;
}
multifd_send_prepare_header(p);
return true;
}