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Re: [Qemu-devel] [PATCH v10 07/14] migration: Create thread infrastructu
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH v10 07/14] migration: Create thread infrastructure for multifd recv side |
Date: |
Wed, 24 Jan 2018 13:34:58 +0000 |
User-agent: |
Mutt/1.9.1 (2017-09-22) |
* Juan Quintela (address@hidden) wrote:
> We make the locking and the transfer of information specific, even if we
> are still receiving things through the main thread.
>
> Signed-off-by: Juan Quintela <address@hidden>
It might be better to split the change to
migration_incoming_process/setup out into a separate patch.
I'm not too sure what it's trying to do here.
> --
>
> We split when we create the main channel and where we start the main
> migration thread, so we wait for the creation of the other threads.
>
> Use multifd_clear_pages().
> Don't remove object_unref()
> We use correctly the channel numbres
> Denife multifd_new_channel/multifd_recv_thread in this patch, that is
> where it is used.
> rename migrate_new_channel to migrate_new_send_channel
> Add ToDo comment
> Add trace
> ---
> migration/migration.c | 5 +-
> migration/migration.h | 1 +
> migration/ram.c | 129
> ++++++++++++++++++++++++++++++++++++++++++++++---
> migration/socket.c | 3 ++
> migration/trace-events | 2 +
> 5 files changed, 132 insertions(+), 8 deletions(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 77fc17f723..1545f3a0b0 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -406,7 +406,7 @@ static void migration_incoming_setup(QEMUFile *f)
> qemu_file_set_blocking(f, false);
> }
>
> -static void migration_incoming_process(void)
> +void migration_incoming_process(void)
> {
> Coroutine *co = qemu_coroutine_create(process_incoming_migration_co,
> NULL);
> qemu_coroutine_enter(co);
> @@ -424,7 +424,8 @@ void migration_ioc_process_incoming(QIOChannel *ioc)
>
> if (!mis->from_src_file) {
> QEMUFile *f = qemu_fopen_channel_input(ioc);
> - migration_fd_process_incoming(f);
> + migration_incoming_setup(f);
> + return;
> }
> multifd_recv_new_channel(ioc);
> }
> diff --git a/migration/migration.h b/migration/migration.h
> index 29a7b79a39..7de193a9c0 100644
> --- a/migration/migration.h
> +++ b/migration/migration.h
> @@ -172,6 +172,7 @@ void migrate_set_state(int *state, int old_state, int
> new_state);
>
> void migration_fd_process_incoming(QEMUFile *f);
> void migration_ioc_process_incoming(QIOChannel *ioc);
> +void migration_incoming_process(void);
>
> bool migration_has_all_channels(void);
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 19c8089c4b..8443806f12 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -660,13 +660,20 @@ static uint16_t multifd_send_page(RAMBlock *block,
> ram_addr_t offset,
> }
>
mostly same comments as the sent side:
> struct MultiFDRecvParams {
> + /* not changed */
?
> uint8_t id;
> char *name;
> QemuThread thread;
> QIOChannel *c;
> + QemuSemaphore ready;
> QemuSemaphore sem;
> QemuMutex mutex;
> + /* proteced by param mutex */
Typo: 't'
> bool quit;
> + /* how many patches has sent this channel */
s/patches/packets/
> + uint32_t packets_recv;
> + multifd_pages_t *pages;
> + bool done;
> };
> typedef struct MultiFDRecvParams MultiFDRecvParams;
>
> @@ -676,6 +683,7 @@ struct {
> int count;
> /* Should we finish */
> bool quit;
> + multifd_pages_t *pages;
> } *multifd_recv_state;
>
> static void terminate_multifd_recv_threads(Error *errp)
> @@ -721,15 +729,51 @@ int multifd_load_cleanup(Error **errp)
> socket_recv_channel_unref(p->c);
> g_free(p->name);
> p->name = NULL;
> + multifd_pages_clear(p->pages);
> + p->pages = NULL;
> }
> g_free(multifd_recv_state->params);
> multifd_recv_state->params = NULL;
> + multifd_pages_clear(multifd_recv_state->pages);
> + multifd_recv_state->pages = NULL;
> g_free(multifd_recv_state);
> multifd_recv_state = NULL;
>
> return ret;
> }
>
> +static void *multifd_recv_thread(void *opaque)
> +{
> + MultiFDRecvParams *p = opaque;
> +
> + qemu_sem_post(&p->ready);
> + while (true) {
> + qemu_mutex_lock(&p->mutex);
> + if (p->quit) {
> + qemu_mutex_unlock(&p->mutex);
> + break;
> + }
> + if (p->pages->used) {
> + p->pages->used = 0;
> +
> + trace_multifd_recv(p->id, p->pages->seq, p->pages->used);
Same as on send, ->used is 0 here
> + /* ToDo: receive pages here */
> +
> + p->done = true;
> + p->packets_recv++;
> + qemu_mutex_unlock(&p->mutex);
> + qemu_sem_post(&p->ready);
> + continue;
> + }
> + qemu_mutex_unlock(&p->mutex);
> + qemu_sem_wait(&p->sem);
> + }
> + trace_multifd_recv_thread(p->id, p->packets_recv);
> +
> + return NULL;
> +}
> +
> int multifd_load_setup(void)
> {
> int thread_count;
> @@ -742,6 +786,8 @@ int multifd_load_setup(void)
> multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count);
> multifd_recv_state->count = 0;
> multifd_recv_state->quit = false;
> + multifd_pages_init(&multifd_recv_state->pages,
> + migrate_multifd_page_count());
What happens if the migrate parameter for multifd-page-count is
different on source and dest?
> return 0;
> }
>
> @@ -752,7 +798,80 @@ int multifd_created_channels(void)
>
> void multifd_recv_new_channel(QIOChannel *ioc)
> {
> - socket_recv_channel_unref(ioc);
> + MultiFDRecvParams *p;
> + MultiFDInit_t msg;
> + Error *local_err = NULL;
> + size_t ret;
> +
> + ret = qio_channel_read_all(ioc, (char *)&msg, sizeof(msg), &local_err);
> + if (ret != 0) {
> + terminate_multifd_recv_threads(local_err);
> + return;
> + }
> +
> + if (memcmp(msg.uuid, &qemu_uuid, sizeof(qemu_uuid))) {
> + char *uuid = qemu_uuid_unparse_strdup(&qemu_uuid);
> + error_setg(&local_err, "multifd: received uuid '%s' and expected "
> + "uuid '%s' for channel %hhd", msg.uuid, uuid, msg.id);
> + g_free(uuid);
> + terminate_multifd_recv_threads(local_err);
> + return;
> + }
> +
> + p = &multifd_recv_state->params[msg.id];
msg.id needs to be checked against the size of params (thread_count ?)
before that array index.
> + if (p->id != 0) {
> + error_setg(&local_err, "multifd: received id '%d' already setup'",
> + msg.id);
> + terminate_multifd_recv_threads(local_err);
> + return;
> + }
> + qemu_mutex_init(&p->mutex);
> + qemu_sem_init(&p->sem, 0);
> + qemu_sem_init(&p->ready, 0);
> + p->quit = false;
> + p->id = msg.id;
> + p->done = false;
> + multifd_pages_init(&p->pages, migrate_multifd_page_count());
> + p->c = ioc;
> + multifd_recv_state->count++;
> + p->name = g_strdup_printf("multifdrecv_%d", msg.id);
> + socket_recv_channel_ref(ioc);
> +
> + qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p,
> + QEMU_THREAD_JOINABLE);
> + if (multifd_recv_state->count == migrate_multifd_channels()) {
> + migration_incoming_process();
> + }
> +}
> +
> +static void multifd_recv_page(RAMBlock *block, ram_addr_t offset,
> + uint8_t *address, uint16_t fd_num)
> +{
> + int thread_count;
> + MultiFDRecvParams *p;
> + multifd_pages_t *pages = multifd_recv_state->pages;
> +
> + pages->iov[pages->used].iov_base = address;
> + pages->iov[pages->used].iov_len = TARGET_PAGE_SIZE;
> + pages->used++;
> +
> + if (fd_num == MULTIFD_CONTINUE) {
> + return;
> + }
> +
> + thread_count = migrate_multifd_channels();
> + assert(fd_num < thread_count);
> + p = &multifd_recv_state->params[fd_num];
> +
> + qemu_sem_wait(&p->ready);
> +
> + qemu_mutex_lock(&p->mutex);
> + p->done = false;
> + p->pages->used = 0;
> + multifd_recv_state->pages = p->pages;
> + p->pages = pages;
This needs a comment; I'm a bit confused - too many things called
'pages' to know what is going where. I think you've just waited for
one of the threads to get data, then passed the received data
out into multifd_recv_state? But then the last p->pages = pages I'm
not sure.
> + qemu_mutex_unlock(&p->mutex);
> + qemu_sem_post(&p->sem);
> }
>
> /**
> @@ -3042,6 +3161,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> }
>
> while (!postcopy_running && !ret && !(flags & RAM_SAVE_FLAG_EOS)) {
> + RAMBlock *block = NULL;
> ram_addr_t addr, total_ram_bytes;
> void *host = NULL;
> uint16_t fd_num;
> @@ -3066,7 +3186,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE |
> RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE |
> RAM_SAVE_FLAG_MULTIFD_PAGE)) {
> - RAMBlock *block = ram_block_from_stream(f, flags);
> + block = ram_block_from_stream(f, flags);
>
> host = host_from_ram_block_offset(block, addr);
> if (!host) {
> @@ -3157,10 +3277,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
>
> case RAM_SAVE_FLAG_MULTIFD_PAGE:
> fd_num = qemu_get_be16(f);
> - if (fd_num != 0) {
> - /* this is yet an unused variable, changed later */
> - fd_num = fd_num;
> - }
> + multifd_recv_page(block, addr, host, fd_num);
> qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
> break;
>
> diff --git a/migration/socket.c b/migration/socket.c
> index aedabee8a1..ba23442175 100644
> --- a/migration/socket.c
> +++ b/migration/socket.c
> @@ -192,6 +192,9 @@ out:
> if (migration_has_all_channels()) {
> /* Close listening socket as its no longer needed */
> qio_channel_close(ioc, NULL);
> + if (!migrate_use_multifd()) {
> + migration_incoming_process();
> + }
> return G_SOURCE_REMOVE;
> } else {
> return G_SOURCE_CONTINUE;
> diff --git a/migration/trace-events b/migration/trace-events
> index 61ee21a13e..06aef4d4a3 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -77,7 +77,9 @@ ram_load_postcopy_loop(uint64_t addr, int flags) "@%"
> PRIx64 " %x"
> ram_postcopy_send_discard_bitmap(void) ""
> ram_save_page(const char *rbname, uint64_t offset, void *host) "%s: offset:
> 0x%" PRIx64 " host: %p"
> ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s:
> start: 0x%zx len: 0x%zx"
> +multifd_recv(char id, int seq, int num) "channel %d sequence %d num pages %d"
> multifd_send(char id, int seq, int num) "channel %d sequence %d num pages %d"
> +multifd_recv_thread(char id, uint32_t packets) "channel %d packets %d"
> multifd_send_thread(char id, uint32_t packets) "channel %d packets %d"
>
> # migration/migration.c
> --
> 2.14.3
>
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- [Qemu-devel] [RFC 00/14] Multifd, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 02/14] migration: Rename initial_bytes, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 01/14] migration: Make migrate_fd_error() the owner of the Error, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 03/14] migration: Drop current address parameter from save_zero_page(), Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 05/14] migration: Create ram_multifd_page, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 07/14] migration: Create thread infrastructure for multifd recv side, Juan Quintela, 2018/01/10
- Re: [Qemu-devel] [PATCH v10 07/14] migration: Create thread infrastructure for multifd recv side,
Dr. David Alan Gilbert <=
- [Qemu-devel] [PATCH v10 04/14] migration: Start of multiple fd work, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 08/14] migration: Transfer pages over new channels, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 06/14] migration: Send the fd number which we are going to use for this page, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 11/14] LOCAL: use trace events for migration-test, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 10/14] migration: Add multifd test, Juan Quintela, 2018/01/10
- [Qemu-devel] [PATCH v10 09/14] migration: Flush receive queue, Juan Quintela, 2018/01/10