Re: [Qemu-devel] [PATCH 2/2] migration: add speed limit for multifd migration

[Wei Yang]

On Mon, Jul 29, 2019 at 10:32:53AM +0800, Ivan Ren wrote:
>Limit the speed of multifd migration through common speed limitation
>qemu file.
>
>Signed-off-by: Ivan Ren <address@hidden>
>---
> migration/ram.c | 22 ++++++++++++----------
> 1 file changed, 12 insertions(+), 10 deletions(-)
>
>diff --git a/migration/ram.c b/migration/ram.c
>index 889148dd84..e3fde16776 100644
>--- a/migration/ram.c
>+++ b/migration/ram.c
>@@ -922,7 +922,7 @@ struct {
>  * false.
>  */
> 
>-static int multifd_send_pages(void)
>+static int multifd_send_pages(RAMState *rs)
> {
>     int i;
>     static int next_channel;
>@@ -954,6 +954,7 @@ static int multifd_send_pages(void)
>     multifd_send_state->pages = p->pages;
>     p->pages = pages;
>     transferred = ((uint64_t) pages->used) * TARGET_PAGE_SIZE + p->packet_len;
>+    qemu_file_update_rate_transfer(rs->f, transferred);
>     ram_counters.multifd_bytes += transferred;
>     ram_counters.transferred += transferred;;
>     qemu_mutex_unlock(&p->mutex);
>@@ -962,7 +963,7 @@ static int multifd_send_pages(void)
>     return 1;
> }
> 
>-static int multifd_queue_page(RAMBlock *block, ram_addr_t offset)
>+static int multifd_queue_page(RAMState *rs, RAMBlock *block, ram_addr_t 
>offset)
> {
>     MultiFDPages_t *pages = multifd_send_state->pages;
> 
>@@ -981,12 +982,12 @@ static int multifd_queue_page(RAMBlock *block, 
>ram_addr_t offset)
>         }
>     }
> 
>-    if (multifd_send_pages() < 0) {
>+    if (multifd_send_pages(rs) < 0) {
>         return -1;
>     }
> 
>     if (pages->block != block) {
>-        return  multifd_queue_page(block, offset);
>+        return  multifd_queue_page(rs, block, offset);
>     }
> 
>     return 1;
>@@ -1054,7 +1055,7 @@ void multifd_save_cleanup(void)
>     multifd_send_state = NULL;
> }
> 
>-static void multifd_send_sync_main(void)
>+static void multifd_send_sync_main(RAMState *rs)
> {
>     int i;
> 
>@@ -1062,7 +1063,7 @@ static void multifd_send_sync_main(void)
>         return;
>     }
>     if (multifd_send_state->pages->used) {
>-        if (multifd_send_pages() < 0) {
>+        if (multifd_send_pages(rs) < 0) {
>             error_report("%s: multifd_send_pages fail", __func__);
>             return;
>         }
>@@ -1083,6 +1084,7 @@ static void multifd_send_sync_main(void)
>         p->packet_num = multifd_send_state->packet_num++;
>         p->flags |= MULTIFD_FLAG_SYNC;
>         p->pending_job++;
>+        qemu_file_update_rate_transfer(rs->f, p->packet_len);

The original code seems forget to update 

    ram_counters.multifd_bytes
    ram_counters.transferred

Sounds we need to update these counters here too.

>         qemu_mutex_unlock(&p->mutex);
>         qemu_sem_post(&p->sem);
>     }
>@@ -2079,7 +2081,7 @@ static int ram_save_page(RAMState *rs, PageSearchStatus 
>*pss, bool last_stage)
> static int ram_save_multifd_page(RAMState *rs, RAMBlock *block,
>                                  ram_addr_t offset)
> {
>-    if (multifd_queue_page(block, offset) < 0) {
>+    if (multifd_queue_page(rs, block, offset) < 0) {
>         return -1;
>     }
>     ram_counters.normal++;
>@@ -3482,7 +3484,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
>     ram_control_before_iterate(f, RAM_CONTROL_SETUP);
>     ram_control_after_iterate(f, RAM_CONTROL_SETUP);
> 
>-    multifd_send_sync_main();
>+    multifd_send_sync_main(*rsp);
>     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
>     qemu_fflush(f);
> 
>@@ -3570,7 +3572,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
>     ram_control_after_iterate(f, RAM_CONTROL_ROUND);
> 
> out:
>-    multifd_send_sync_main();
>+    multifd_send_sync_main(rs);
>     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
>     qemu_fflush(f);
>     ram_counters.transferred += 8;
>@@ -3629,7 +3631,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
> 
>     rcu_read_unlock();
> 
>-    multifd_send_sync_main();
>+    multifd_send_sync_main(rs);
>     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
>     qemu_fflush(f);
> 
>-- 
>2.17.2 (Apple Git-113)
>

-- 
Wei Yang
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