Merge tag 'dirtylimit-dirtyrate-pull-request' of https://github.com/n…

…ewfriday/qemu into staging

Dirtylimit and dirtyrate 20230829 patches PULL request

Correct memory leaks in dirtylimit and accuracy losses in
dirtyrate, respectively; make minor corrections to overshoot
and memory deallocation.

This is v3 with a signed tag. Please apply.

Thanks, Yong.

# -----BEGIN PGP SIGNATURE-----
# Version: GnuPG v2.0.22 (GNU/Linux)
#
# iQIcBAABAgAGBQJk7VtOAAoJEN/yI9az/suchasP/j/7DQTggrrB/2lWhB79BTrT
# L+Tgljh9zynrJeL/OjvE7VD3sxDcHQmHprGT7FkdgIdd3fHl8GHnFz8L1CMLg63E
# i/4SY3RFIvmMqMrmBNx77+D6nSfezKrkwmoln7VGjK6rC0s86PRok+Dxf4SaoP1i
# cCeFOq2O0U/im1fQQl0uETqxYAX+StVRhnpWTqpPFBBaVCmCGQx3WWXGXXFOl5PB
# JNLgDX3lxSpSIfRK9vCb61gFe8gMp+5hUDZgfUln9fmXrO6NsVgHEjvsMqm9UZO1
# tNGSh1GNmO2du6m2iCzVChB8bfe9P3g/XAubfRIkqZtWZK8lhz1mVQEg4wJ4VgX1
# uMAi8gzpMV5Rdiy9MWYZW9sCuoiZepksBuGtrFMBXXyCpP76N+uWshfj+/Mp2mt0
# 475ZiC4silwCeRDWH4UkTyNQtc7+WVRjZP0ToXuUOSyWFdyRPCQdAIDlUacxk/9p
# BSymBM2P760oa4IMCwhey5/WaFdfFFcMD4e2UwfTpafwY5uwVOTxN23k7+iCivQs
# 3RbP8ghvakgNPTO+1HcdoRW/LrjnGn1mZ5qvLj1+f7slP5NEsBDZVEylQJIHjXh4
# oE8OwB/rRexlUGRUuIgMpVeEk8/LcEMy73I+dj/zSkfQEw8KuCp6EUB5HFiciS0/
# IG5X0TdcvAdicG8qmDGx
# =NKkN
# -----END PGP SIGNATURE-----
# gpg: Signature made Mon 28 Aug 2023 22:43:26 EDT
# gpg:                using RSA key DFF223D6B3FECB9C
# gpg: Can't check signature: No public key

* tag 'dirtylimit-dirtyrate-pull-request' of https://github.com/newfriday/qemu:
  migration/dirtyrate: Fix precision losses and g_usleep overshoot
  softmmu/dirtylimit: Convert free to g_free
  softmmu: Fix dirtylimit memory leak

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

migration/dirtyrate.c

@@ -57,6 +57,8 @@ static int64_t dirty_stat_wait(int64_t msec, int64_t initial_time)
         msec = current_time - initial_time;
     } else {
         g_usleep((msec + initial_time - current_time) * 1000);
+        /* g_usleep may overshoot */
+        msec = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - initial_time;
     }
 
     return msec;
@@ -77,9 +79,13 @@ static int64_t do_calculate_dirtyrate(DirtyPageRecord dirty_pages,
 {
     uint64_t increased_dirty_pages =
         dirty_pages.end_pages - dirty_pages.start_pages;
-    uint64_t memory_size_MiB = qemu_target_pages_to_MiB(increased_dirty_pages);
 
-    return memory_size_MiB * 1000 / calc_time_ms;
+    /*
+     * multiply by 1000ms/s _before_ converting down to megabytes
+     * to avoid losing precision
+     */
+    return qemu_target_pages_to_MiB(increased_dirty_pages * 1000) /
+        calc_time_ms;
 }
 
 void global_dirty_log_change(unsigned int flag, bool start)

softmmu/dirtylimit.c

@@ -100,7 +100,7 @@ static void vcpu_dirty_rate_stat_collect(void)
             stat.rates[i].dirty_rate;
     }
 
-    free(stat.rates);
+    g_free(stat.rates);
 }
 
 static void *vcpu_dirty_rate_stat_thread(void *opaque)
@@ -171,10 +171,10 @@ void vcpu_dirty_rate_stat_initialize(void)
 
 void vcpu_dirty_rate_stat_finalize(void)
 {
-    free(vcpu_dirty_rate_stat->stat.rates);
+    g_free(vcpu_dirty_rate_stat->stat.rates);
     vcpu_dirty_rate_stat->stat.rates = NULL;
 
-    free(vcpu_dirty_rate_stat);
+    g_free(vcpu_dirty_rate_stat);
     vcpu_dirty_rate_stat = NULL;
 }
 
@@ -220,10 +220,10 @@ void dirtylimit_state_initialize(void)
 
 void dirtylimit_state_finalize(void)
 {
-    free(dirtylimit_state->states);
+    g_free(dirtylimit_state->states);
     dirtylimit_state->states = NULL;
 
-    free(dirtylimit_state);
+    g_free(dirtylimit_state);
     dirtylimit_state = NULL;
 
     trace_dirtylimit_state_finalize();
@@ -653,28 +653,26 @@ struct DirtyLimitInfoList *qmp_query_vcpu_dirty_limit(Error **errp)
 
 void hmp_info_vcpu_dirty_limit(Monitor *mon, const QDict *qdict)
 {
-    DirtyLimitInfoList *limit, *head, *info = NULL;
+    DirtyLimitInfoList *info;
+    g_autoptr(DirtyLimitInfoList) head = NULL;
     Error *err = NULL;
 
     if (!dirtylimit_in_service()) {
         monitor_printf(mon, "Dirty page limit not enabled!\n");
         return;
     }
 
-    info = qmp_query_vcpu_dirty_limit(&err);
+    head = qmp_query_vcpu_dirty_limit(&err);
     if (err) {
         hmp_handle_error(mon, err);
         return;
     }
 
-    head = info;
-    for (limit = head; limit != NULL; limit = limit->next) {
+    for (info = head; info != NULL; info = info->next) {
         monitor_printf(mon, "vcpu[%"PRIi64"], limit rate %"PRIi64 " (MB/s),"
                             " current rate %"PRIi64 " (MB/s)\n",
-                            limit->value->cpu_index,
-                            limit->value->limit_rate,
-                            limit->value->current_rate);
+                            info->value->cpu_index,
+                            info->value->limit_rate,
+                            info->value->current_rate);
     }
-
-    g_free(info);
 }