On 04/10/2017 12:46, Juan Quintela wrote:
> The function still don't use multifd, but we have simplified
> ram_save_page, xbzrle and RDMA stuff is gone. We have added a new
> counter and a new flag for this type of pages.
>
> Signed-off-by: Juan Quintela <quint...@redhat.com>
I still disagree with the approach, and still haven't gotten a good
explanation of why it is too difficult to just have multiple migration
streams.
Paolo
> --
> Add last_page parameter
> Add commets for done and address
> Remove multifd field, it is the same than normal pages
> Merge next patch, now we send multiple pages at a time
> Remove counter for multifd pages, it is identical to normal pages
> Use iovec's instead of creating the equivalent.
> Clear memory used by pages (dave)
> Use g_new0(danp)
> define MULTIFD_CONTINUE
> ---
> migration/ram.c | 132
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 131 insertions(+), 1 deletion(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index b57006594b..c0af538f5f 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -50,6 +50,7 @@
> #include "migration/block.h"
> #include "sysemu/sysemu.h"
> #include "qemu/uuid.h"
> +#include "qemu/iov.h"
>
> /***********************************************************/
> /* ram save/restore */
> @@ -69,6 +70,7 @@
> #define RAM_SAVE_FLAG_XBZRLE 0x40
> /* 0x80 is reserved in migration.h start with 0x100 next */
> #define RAM_SAVE_FLAG_COMPRESS_PAGE 0x100
> +#define RAM_SAVE_FLAG_MULTIFD_PAGE 0x200
>
> static inline bool is_zero_range(uint8_t *p, uint64_t size)
> {
> @@ -362,14 +364,29 @@ static void compress_threads_save_setup(void)
>
> /* Multiple fd's */
>
> +/* used to continue on the same multifd group */
> +#define MULTIFD_CONTINUE UINT16_MAX
> +
> +typedef struct {
> + int num;
> + size_t size;
> + struct iovec *iov;
> +} multifd_pages_t;
> +
> struct MultiFDSendParams {
> + /* not changed */
> uint8_t id;
> char *name;
> QemuThread thread;
> QIOChannel *c;
> QemuSemaphore sem;
> QemuMutex mutex;
> + /* protected by param mutex */
> bool quit;
> + multifd_pages_t pages;
> + /* protected by multifd mutex */
> + /* has the thread finish the last submitted job */
> + bool done;
> };
> typedef struct MultiFDSendParams MultiFDSendParams;
>
> @@ -377,8 +394,26 @@ struct {
> MultiFDSendParams *params;
> /* number of created threads */
> int count;
> + QemuMutex mutex;
> + QemuSemaphore sem;
> + multifd_pages_t pages;
> } *multifd_send_state;
>
> +static void multifd_init_pages(multifd_pages_t *pages)
> +{
> + pages->num = 0;
> + pages->size = migrate_multifd_page_count();
> + pages->iov = g_new0(struct iovec, pages->size);
> +}
> +
> +static void multifd_clear_pages(multifd_pages_t *pages)
> +{
> + pages->num = 0;
> + pages->size = 0;
> + g_free(pages->iov);
> + pages->iov = NULL;
> +}
> +
> static void terminate_multifd_send_threads(Error *errp)
> {
> int i;
> @@ -417,9 +452,11 @@ int multifd_save_cleanup(Error **errp)
> socket_send_channel_destroy(p->c);
> g_free(p->name);
> p->name = NULL;
> + multifd_clear_pages(&p->pages);
> }
> g_free(multifd_send_state->params);
> multifd_send_state->params = NULL;
> + multifd_clear_pages(&multifd_send_state->pages);
> g_free(multifd_send_state);
> multifd_send_state = NULL;
> return ret;
> @@ -446,6 +483,7 @@ static void *multifd_send_thread(void *opaque)
> terminate_multifd_send_threads(local_err);
> return NULL;
> }
> + qemu_sem_post(&multifd_send_state->sem);
>
> while (true) {
> qemu_mutex_lock(&p->mutex);
> @@ -453,6 +491,15 @@ static void *multifd_send_thread(void *opaque)
> qemu_mutex_unlock(&p->mutex);
> break;
> }
> + if (p->pages.num) {
> + p->pages.num = 0;
> + qemu_mutex_unlock(&p->mutex);
> + qemu_mutex_lock(&multifd_send_state->mutex);
> + p->done = true;
> + qemu_mutex_unlock(&multifd_send_state->mutex);
> + qemu_sem_post(&multifd_send_state->sem);
> + continue;
> + }
> qemu_mutex_unlock(&p->mutex);
> qemu_sem_wait(&p->sem);
> }
> @@ -493,6 +540,9 @@ int multifd_save_setup(void)
> multifd_send_state = g_malloc0(sizeof(*multifd_send_state));
> multifd_send_state->params = g_new0(MultiFDSendParams, thread_count);
> multifd_send_state->count = 0;
> + qemu_mutex_init(&multifd_send_state->mutex);
> + qemu_sem_init(&multifd_send_state->sem, 0);
> + multifd_init_pages(&multifd_send_state->pages);
> for (i = 0; i < thread_count; i++) {
> MultiFDSendParams *p = &multifd_send_state->params[i];
>
> @@ -500,12 +550,52 @@ int multifd_save_setup(void)
> qemu_sem_init(&p->sem, 0);
> p->quit = false;
> p->id = i;
> + p->done = true;
> + multifd_init_pages(&p->pages);
> p->name = g_strdup_printf("multifdsend_%d", i);
> socket_send_channel_create(multifd_new_channel_async, p);
> }
> return 0;
> }
>
> +static uint16_t multifd_send_page(uint8_t *address, bool last_page)
> +{
> + int i;
> + MultiFDSendParams *p = NULL; /* make happy gcc */
> + multifd_pages_t *pages = &multifd_send_state->pages;
> +
> + pages->iov[pages->num].iov_base = address;
> + pages->iov[pages->num].iov_len = TARGET_PAGE_SIZE;
> + pages->num++;
> +
> + if (!last_page) {
> + if (pages->num < (pages->size - 1)) {
> + return MULTIFD_CONTINUE;
> + }
> + }
> +
> + qemu_sem_wait(&multifd_send_state->sem);
> + qemu_mutex_lock(&multifd_send_state->mutex);
> + for (i = 0; i < multifd_send_state->count; i++) {
> + p = &multifd_send_state->params[i];
> +
> + if (p->done) {
> + p->done = false;
> + break;
> + }
> + }
> + qemu_mutex_unlock(&multifd_send_state->mutex);
> + qemu_mutex_lock(&p->mutex);
> + p->pages.num = pages->num;
> + iov_copy(p->pages.iov, pages->num, pages->iov, pages->num, 0,
> + iov_size(pages->iov, pages->num));
> + pages->num = 0;
> + qemu_mutex_unlock(&p->mutex);
> + qemu_sem_post(&p->sem);
> +
> + return 0;
> +}
> +
> struct MultiFDRecvParams {
> uint8_t id;
> char *name;
> @@ -1086,6 +1176,31 @@ static int ram_save_page(RAMState *rs,
> PageSearchStatus *pss, bool last_stage)
> return pages;
> }
>
> +static int ram_multifd_page(RAMState *rs, PageSearchStatus *pss,
> + bool last_stage)
> +{
> + int pages;
> + uint8_t *p;
> + RAMBlock *block = pss->block;
> + ram_addr_t offset = pss->page << TARGET_PAGE_BITS;
> +
> + p = block->host + offset;
> +
> + pages = save_zero_page(rs, block, offset, p);
> + if (pages == -1) {
> + ram_counters.transferred +=
> + save_page_header(rs, rs->f, block,
> + offset | RAM_SAVE_FLAG_MULTIFD_PAGE);
> + qemu_put_buffer(rs->f, p, TARGET_PAGE_SIZE);
> + multifd_send_page(p, rs->migration_dirty_pages == 1);
> + ram_counters.transferred += TARGET_PAGE_SIZE;
> + pages = 1;
> + ram_counters.normal++;
> + }
> +
> + return pages;
> +}
> +
> static int do_compress_ram_page(QEMUFile *f, RAMBlock *block,
> ram_addr_t offset)
> {
> @@ -1514,6 +1629,8 @@ static int ram_save_target_page(RAMState *rs,
> PageSearchStatus *pss,
> if (migrate_use_compression() &&
> (rs->ram_bulk_stage || !migrate_use_xbzrle())) {
> res = ram_save_compressed_page(rs, pss, last_stage);
> + } else if (migrate_use_multifd()) {
> + res = ram_multifd_page(rs, pss, last_stage);
> } else {
> res = ram_save_page(rs, pss, last_stage);
> }
> @@ -2810,6 +2927,10 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> if (!migrate_use_compression()) {
> invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE;
> }
> +
> + if (!migrate_use_multifd()) {
> + invalid_flags |= RAM_SAVE_FLAG_MULTIFD_PAGE;
> + }
> /* This RCU critical section can be very long running.
> * When RCU reclaims in the code start to become numerous,
> * it will be necessary to reduce the granularity of this
> @@ -2834,13 +2955,17 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> if (flags & invalid_flags & RAM_SAVE_FLAG_COMPRESS_PAGE) {
> error_report("Received an unexpected compressed page");
> }
> + if (flags & invalid_flags & RAM_SAVE_FLAG_MULTIFD_PAGE) {
> + error_report("Received an unexpected multifd 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_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE |
> + RAM_SAVE_FLAG_MULTIFD_PAGE)) {
> RAMBlock *block = ram_block_from_stream(f, flags);
>
> host = host_from_ram_block_offset(block, addr);
> @@ -2928,6 +3053,11 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> break;
> }
> break;
> +
> + case RAM_SAVE_FLAG_MULTIFD_PAGE:
> + qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
> + break;
> +
> case RAM_SAVE_FLAG_EOS:
> /* normal exit */
> break;
>
