diff mbox series

[v7,05/13] multifd: Count the number of bytes sent correctly

Message ID 20220531104318.7494-6-quintela@redhat.com
State New
Headers show
Series Migration: Transmit and detect zero pages in the multifd threads | expand

Commit Message

Juan Quintela May 31, 2022, 10:43 a.m. UTC
Current code asumes that all pages are whole.  That is not true for
example for compression already.  Fix it for creating a new field
->sent_bytes that includes it.

All ram_counters are used only from the migration thread, so we have
two options:
- put a mutex and fill everything when we sent it (not only
ram_counters, also qemu_file->xfer_bytes).
- Create a local variable that implements how much has been sent
through each channel.  And when we push another packet, we "add" the
previous stats.

I choose two due to less changes overall.  On the previous code we
increase transferred and then we sent.  Current code goes the other
way around.  It sents the data, and after the fact, it updates the
counters.  Notice that each channel can have a maximum of half a
megabyte of data without counting, so it is not very important.

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/multifd.h |  2 ++
 migration/multifd.c | 14 ++++++--------
 2 files changed, 8 insertions(+), 8 deletions(-)

Comments

Zhang, Chen June 8, 2022, 8:50 a.m. UTC | #1
> -----Original Message-----
> From: Qemu-devel <qemu-devel-
> bounces+chen.zhang=intel.com@nongnu.org> On Behalf Of Juan Quintela
> Sent: Tuesday, May 31, 2022 6:43 PM
> To: qemu-devel@nongnu.org
> Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>; Philippe Mathieu-
> Daudé <f4bug@amsat.org>; Yanan Wang <wangyanan55@huawei.com>; Dr.
> David Alan Gilbert <dgilbert@redhat.com>; Juan Quintela
> <quintela@redhat.com>; Eduardo Habkost <eduardo@habkost.net>; Peter
> Xu <peterx@redhat.com>; Leonardo Bras <leobras@redhat.com>
> Subject: [PATCH v7 05/13] multifd: Count the number of bytes sent correctly
> 
> Current code asumes that all pages are whole.  That is not true for example
> for compression already.  Fix it for creating a new field
> ->sent_bytes that includes it.
> 
> All ram_counters are used only from the migration thread, so we have two
> options:
> - put a mutex and fill everything when we sent it (not only ram_counters,
> also qemu_file->xfer_bytes).
> - Create a local variable that implements how much has been sent through
> each channel.  And when we push another packet, we "add" the previous
> stats.
> 
> I choose two due to less changes overall.  On the previous code we increase
> transferred and then we sent.  Current code goes the other way around.  It
> sents the data, and after the fact, it updates the counters.  Notice that each
> channel can have a maximum of half a megabyte of data without counting, so
> it is not very important.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  migration/multifd.h |  2 ++
>  migration/multifd.c | 14 ++++++--------
>  2 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/migration/multifd.h b/migration/multifd.h index
> 71f49b4063..8a45dda58c 100644
> --- a/migration/multifd.h
> +++ b/migration/multifd.h
> @@ -102,6 +102,8 @@ typedef struct {
>      uint32_t flags;
>      /* global number of generated multifd packets */
>      uint64_t packet_num;
> +    /* How many bytes have we sent on the last packet */
> +    uint64_t sent_bytes;
>      /* thread has work to do */
>      int pending_job;
>      /* array of pages to sent.
> diff --git a/migration/multifd.c b/migration/multifd.c index
> 166246b9b7..eef47c274f 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -394,7 +394,6 @@ static int multifd_send_pages(QEMUFile *f)
>      static int next_channel;
>      MultiFDSendParams *p = NULL; /* make happy gcc */
>      MultiFDPages_t *pages = multifd_send_state->pages;
> -    uint64_t transferred;
> 
>      if (qatomic_read(&multifd_send_state->exiting)) {
>          return -1;
> @@ -429,10 +428,10 @@ static int multifd_send_pages(QEMUFile *f)
>      p->packet_num = multifd_send_state->packet_num++;
>      multifd_send_state->pages = p->pages;
>      p->pages = pages;
> -    transferred = ((uint64_t) pages->num) * p->page_size + p->packet_len;
> -    qemu_file_update_transfer(f, transferred);
> -    ram_counters.multifd_bytes += transferred;
> -    ram_counters.transferred += transferred;
> +    ram_transferred_add(p->sent_bytes);
> +    ram_counters.multifd_bytes += p->sent_bytes;
> +    qemu_file_update_transfer(f, p->sent_bytes);
> +    p->sent_bytes = 0;
>      qemu_mutex_unlock(&p->mutex);
>      qemu_sem_post(&p->sem);
> 
> @@ -605,9 +604,6 @@ int multifd_send_sync_main(QEMUFile *f)
>          p->packet_num = multifd_send_state->packet_num++;
>          p->flags |= MULTIFD_FLAG_SYNC;
>          p->pending_job++;
> -        qemu_file_update_transfer(f, p->packet_len);
> -        ram_counters.multifd_bytes += p->packet_len;
> -        ram_counters.transferred += p->packet_len;
>          qemu_mutex_unlock(&p->mutex);
>          qemu_sem_post(&p->sem);
> 
> @@ -712,6 +708,8 @@ static void *multifd_send_thread(void *opaque)
>              }
> 
>              qemu_mutex_lock(&p->mutex);
> +            p->sent_bytes += p->packet_len;;

Typo here about ";;" ? 

Thanks
Chen

> +            p->sent_bytes += p->next_packet_size;
>              p->pending_job--;
>              qemu_mutex_unlock(&p->mutex);
> 
> --
> 2.35.3
>
Dr. David Alan Gilbert July 14, 2022, 12:33 p.m. UTC | #2
* Juan Quintela (quintela@redhat.com) wrote:
> Current code asumes that all pages are whole.  That is not true for
> example for compression already.  Fix it for creating a new field
> ->sent_bytes that includes it.
> 
> All ram_counters are used only from the migration thread, so we have
> two options:
> - put a mutex and fill everything when we sent it (not only
> ram_counters, also qemu_file->xfer_bytes).
> - Create a local variable that implements how much has been sent
> through each channel.  And when we push another packet, we "add" the
> previous stats.
> 
> I choose two due to less changes overall.  On the previous code we
> increase transferred and then we sent.  Current code goes the other
> way around.  It sents the data, and after the fact, it updates the
> counters.  Notice that each channel can have a maximum of half a
> megabyte of data without counting, so it is not very important.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  migration/multifd.h |  2 ++
>  migration/multifd.c | 14 ++++++--------
>  2 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/migration/multifd.h b/migration/multifd.h
> index 71f49b4063..8a45dda58c 100644
> --- a/migration/multifd.h
> +++ b/migration/multifd.h
> @@ -102,6 +102,8 @@ typedef struct {
>      uint32_t flags;
>      /* global number of generated multifd packets */
>      uint64_t packet_num;
> +    /* How many bytes have we sent on the last packet */
> +    uint64_t sent_bytes;
>      /* thread has work to do */
>      int pending_job;
>      /* array of pages to sent.
> diff --git a/migration/multifd.c b/migration/multifd.c
> index 166246b9b7..eef47c274f 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -394,7 +394,6 @@ static int multifd_send_pages(QEMUFile *f)
>      static int next_channel;
>      MultiFDSendParams *p = NULL; /* make happy gcc */
>      MultiFDPages_t *pages = multifd_send_state->pages;
> -    uint64_t transferred;
>  
>      if (qatomic_read(&multifd_send_state->exiting)) {
>          return -1;
> @@ -429,10 +428,10 @@ static int multifd_send_pages(QEMUFile *f)
>      p->packet_num = multifd_send_state->packet_num++;
>      multifd_send_state->pages = p->pages;
>      p->pages = pages;
> -    transferred = ((uint64_t) pages->num) * p->page_size + p->packet_len;
> -    qemu_file_update_transfer(f, transferred);
> -    ram_counters.multifd_bytes += transferred;
> -    ram_counters.transferred += transferred;
> +    ram_transferred_add(p->sent_bytes);
> +    ram_counters.multifd_bytes += p->sent_bytes;
> +    qemu_file_update_transfer(f, p->sent_bytes);

Note that got renamed in bc698c367d6fac15454ee3ff6bb168e43c151465
but other than that


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> +    p->sent_bytes = 0;
>      qemu_mutex_unlock(&p->mutex);
>      qemu_sem_post(&p->sem);
>  
> @@ -605,9 +604,6 @@ int multifd_send_sync_main(QEMUFile *f)
>          p->packet_num = multifd_send_state->packet_num++;
>          p->flags |= MULTIFD_FLAG_SYNC;
>          p->pending_job++;
> -        qemu_file_update_transfer(f, p->packet_len);
> -        ram_counters.multifd_bytes += p->packet_len;
> -        ram_counters.transferred += p->packet_len;
>          qemu_mutex_unlock(&p->mutex);
>          qemu_sem_post(&p->sem);
>  
> @@ -712,6 +708,8 @@ static void *multifd_send_thread(void *opaque)
>              }
>  
>              qemu_mutex_lock(&p->mutex);
> +            p->sent_bytes += p->packet_len;;
> +            p->sent_bytes += p->next_packet_size;
>              p->pending_job--;
>              qemu_mutex_unlock(&p->mutex);
>  
> -- 
> 2.35.3
>
diff mbox series

Patch

diff --git a/migration/multifd.h b/migration/multifd.h
index 71f49b4063..8a45dda58c 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -102,6 +102,8 @@  typedef struct {
     uint32_t flags;
     /* global number of generated multifd packets */
     uint64_t packet_num;
+    /* How many bytes have we sent on the last packet */
+    uint64_t sent_bytes;
     /* thread has work to do */
     int pending_job;
     /* array of pages to sent.
diff --git a/migration/multifd.c b/migration/multifd.c
index 166246b9b7..eef47c274f 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -394,7 +394,6 @@  static int multifd_send_pages(QEMUFile *f)
     static int next_channel;
     MultiFDSendParams *p = NULL; /* make happy gcc */
     MultiFDPages_t *pages = multifd_send_state->pages;
-    uint64_t transferred;
 
     if (qatomic_read(&multifd_send_state->exiting)) {
         return -1;
@@ -429,10 +428,10 @@  static int multifd_send_pages(QEMUFile *f)
     p->packet_num = multifd_send_state->packet_num++;
     multifd_send_state->pages = p->pages;
     p->pages = pages;
-    transferred = ((uint64_t) pages->num) * p->page_size + p->packet_len;
-    qemu_file_update_transfer(f, transferred);
-    ram_counters.multifd_bytes += transferred;
-    ram_counters.transferred += transferred;
+    ram_transferred_add(p->sent_bytes);
+    ram_counters.multifd_bytes += p->sent_bytes;
+    qemu_file_update_transfer(f, p->sent_bytes);
+    p->sent_bytes = 0;
     qemu_mutex_unlock(&p->mutex);
     qemu_sem_post(&p->sem);
 
@@ -605,9 +604,6 @@  int multifd_send_sync_main(QEMUFile *f)
         p->packet_num = multifd_send_state->packet_num++;
         p->flags |= MULTIFD_FLAG_SYNC;
         p->pending_job++;
-        qemu_file_update_transfer(f, p->packet_len);
-        ram_counters.multifd_bytes += p->packet_len;
-        ram_counters.transferred += p->packet_len;
         qemu_mutex_unlock(&p->mutex);
         qemu_sem_post(&p->sem);
 
@@ -712,6 +708,8 @@  static void *multifd_send_thread(void *opaque)
             }
 
             qemu_mutex_lock(&p->mutex);
+            p->sent_bytes += p->packet_len;;
+            p->sent_bytes += p->next_packet_size;
             p->pending_job--;
             qemu_mutex_unlock(&p->mutex);