From 8c3794d709eefdae777477bef7ff3511d55bf418 Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Wed, 14 Aug 2019 04:02:14 +0200
Subject: [PATCH 05/10] migration: Make global sem_sync semaphore by channel

This makes easy to debug things because when you want for all threads
to arrive at that semaphore, you know which one your are waiting for.

Change-Id: I533af8cdc68f619b68eff8e4e573c4de371a3954
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20190814020218.1868-3-quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/ram.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index c75716bb..51811c2d 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -661,6 +661,8 @@ typedef struct {
     uint64_t num_packets;
     /* pages sent through this channel */
     uint64_t num_pages;
+    /* syncs main thread and channels */
+    QemuSemaphore sem_sync;
 }  MultiFDSendParams;

 typedef struct {
@@ -896,8 +898,6 @@ struct {
     MultiFDSendParams *params;
     /* array of pages to sent */
     MultiFDPages_t *pages;
-    /* syncs main thread and channels */
-    QemuSemaphore sem_sync;
     /* global number of generated multifd packets */
     uint64_t packet_num;
     /* send channels ready */
@@ -1037,6 +1037,7 @@ void multifd_save_cleanup(void)
         p->c = NULL;
         qemu_mutex_destroy(&p->mutex);
         qemu_sem_destroy(&p->sem);
+        qemu_sem_destroy(&p->sem_sync);
         g_free(p->name);
         p->name = NULL;
         multifd_pages_clear(p->pages);
@@ -1046,7 +1047,6 @@ void multifd_save_cleanup(void)
         p->packet = NULL;
     }
     qemu_sem_destroy(&multifd_send_state->channels_ready);
-    qemu_sem_destroy(&multifd_send_state->sem_sync);
     g_free(multifd_send_state->params);
     multifd_send_state->params = NULL;
     multifd_pages_clear(multifd_send_state->pages);
@@ -1096,7 +1096,7 @@ static void multifd_send_sync_main(RAMState *rs)
         MultiFDSendParams *p = &multifd_send_state->params[i];

         trace_multifd_send_sync_main_wait(p->id);
-        qemu_sem_wait(&multifd_send_state->sem_sync);
+        qemu_sem_wait(&p->sem_sync);
     }
     trace_multifd_send_sync_main(multifd_send_state->packet_num);
 }
@@ -1156,7 +1156,7 @@ static void *multifd_send_thread(void *opaque)
             qemu_mutex_unlock(&p->mutex);

             if (flags & MULTIFD_FLAG_SYNC) {
-                qemu_sem_post(&multifd_send_state->sem_sync);
+                qemu_sem_post(&p->sem_sync);
             }
             qemu_sem_post(&multifd_send_state->channels_ready);
         } else if (p->quit) {
@@ -1179,7 +1179,7 @@ out:
      */
     if (ret != 0) {
         if (flags & MULTIFD_FLAG_SYNC) {
-            qemu_sem_post(&multifd_send_state->sem_sync);
+            qemu_sem_post(&p->sem_sync);
         }
         qemu_sem_post(&multifd_send_state->channels_ready);
     }
@@ -1225,7 +1225,6 @@ 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->pages = multifd_pages_init(page_count);
-    qemu_sem_init(&multifd_send_state->sem_sync, 0);
     qemu_sem_init(&multifd_send_state->channels_ready, 0);

     for (i = 0; i < thread_count; i++) {
@@ -1233,6 +1232,7 @@ int multifd_save_setup(void)

         qemu_mutex_init(&p->mutex);
         qemu_sem_init(&p->sem, 0);
+        qemu_sem_init(&p->sem_sync, 0);
         p->quit = false;
         p->pending_job = 0;
         p->id = i;
--
2.19.1