This way we can make them atomic and use this functions from any
place.  I also moved all functions that use rate_limit to
migration-stats.

Functions got renamed, they are not qemu_file anymore.

qemu_file_rate_limit -> migration_rate_limit_exceeded
qemu_file_set_rate_limit -> migration_rate_limit_set
qemu_file_get_rate_limit -> migration_rate_limit_get
qemu_file_reset_rate_limit -> migration_rate_limit_reset
qemu_file_acct_rate_limit -> migration_rate_limit_account.

Signed-off-by: Juan Quintela <quintela@redhat.com>

---

If you have any good suggestion for better names, I am all ears.
---
 hw/ppc/spapr.c                      |  5 +--
 hw/s390x/s390-stattrib.c            |  2 +-
 include/migration/qemu-file-types.h |  2 +-
 migration/block-dirty-bitmap.c      |  2 +-
 migration/block.c                   |  5 +--
 migration/migration-stats.c         | 41 ++++++++++++++++++++++
 migration/migration-stats.h         | 42 +++++++++++++++++++++++
 migration/migration.c               | 14 ++++----
 migration/multifd.c                 |  2 +-
 migration/options.c                 |  7 ++--
 migration/qemu-file.c               | 53 ++---------------------------
 migration/qemu-file.h               | 11 ------
 migration/ram.c                     |  2 +-
 migration/savevm.c                  |  2 +-
 14 files changed, 108 insertions(+), 82 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index ddc9c7b1a1..dbd2753278 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2166,7 +2166,7 @@ static void htab_save_first_pass(QEMUFile *f, SpaprMachineState *spapr,
                 break;
             }
         }
-    } while ((index < htabslots) && !qemu_file_rate_limit(f));
+    } while ((index < htabslots) && !migration_rate_limit_exceeded(f));
 
     if (index >= htabslots) {
         assert(index == htabslots);
@@ -2237,7 +2237,8 @@ static int htab_save_later_pass(QEMUFile *f, SpaprMachineState *spapr,
             assert(index == htabslots);
             index = 0;
         }
-    } while ((examined < htabslots) && (!qemu_file_rate_limit(f) || final));
+    } while ((examined < htabslots) &&
+             (!migration_rate_limit_exceeded(f) || final));
 
     if (index >= htabslots) {
         assert(index == htabslots);
diff --git a/hw/s390x/s390-stattrib.c b/hw/s390x/s390-stattrib.c
index aed919ad7d..fb0a20f2e1 100644
--- a/hw/s390x/s390-stattrib.c
+++ b/hw/s390x/s390-stattrib.c
@@ -209,7 +209,7 @@ static int cmma_save(QEMUFile *f, void *opaque, int final)
         return -ENOMEM;
     }
 
-    while (final ? 1 : qemu_file_rate_limit(f) == 0) {
+    while (final ? 1 : migration_rate_limit_exceeded(f) == 0) {
         reallen = sac->get_stattr(sas, &start_gfn, buflen, buf);
         if (reallen < 0) {
             g_free(buf);
diff --git a/include/migration/qemu-file-types.h b/include/migration/qemu-file-types.h
index 1436f9ce92..0354f45198 100644
--- a/include/migration/qemu-file-types.h
+++ b/include/migration/qemu-file-types.h
@@ -165,6 +165,6 @@ size_t coroutine_mixed_fn qemu_get_counted_string(QEMUFile *f, char buf[256]);
 
 void qemu_put_counted_string(QEMUFile *f, const char *name);
 
-int qemu_file_rate_limit(QEMUFile *f);
+bool migration_rate_limit_exceeded(QEMUFile *f);
 
 #endif
diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index 20f36e6bd8..a815678926 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -706,7 +706,7 @@ static void bulk_phase(QEMUFile *f, DBMSaveState *s, bool limit)
     QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
         while (!dbms->bulk_completed) {
             bulk_phase_send_chunk(f, s, dbms);
-            if (limit && qemu_file_rate_limit(f)) {
+            if (limit && migration_rate_limit_exceeded(f)) {
                 return;
             }
         }
diff --git a/migration/block.c b/migration/block.c
index 12617b4152..fc1caa9ca6 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -23,6 +23,7 @@
 #include "block/dirty-bitmap.h"
 #include "migration/misc.h"
 #include "migration.h"
+#include "migration-stats.h"
 #include "migration/register.h"
 #include "qemu-file.h"
 #include "migration/vmstate.h"
@@ -625,7 +626,7 @@ static int flush_blks(QEMUFile *f)
 
     blk_mig_lock();
     while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
-        if (qemu_file_rate_limit(f)) {
+        if (migration_rate_limit_exceeded(f)) {
             break;
         }
         if (blk->ret < 0) {
@@ -762,7 +763,7 @@ static int block_save_iterate(QEMUFile *f, void *opaque)
     /* control the rate of transfer */
     blk_mig_lock();
     while (block_mig_state.read_done * BLK_MIG_BLOCK_SIZE <
-           qemu_file_get_rate_limit(f) &&
+           migration_rate_limit_get() &&
            block_mig_state.submitted < MAX_PARALLEL_IO &&
            (block_mig_state.submitted + block_mig_state.read_done) <
            MAX_IO_BUFFERS) {
diff --git a/migration/migration-stats.c b/migration/migration-stats.c
index 5278c6c821..e01842cabc 100644
--- a/migration/migration-stats.c
+++ b/migration/migration-stats.c
@@ -13,6 +13,7 @@
 #include "qemu/osdep.h"
 #include "qemu/stats64.h"
 #include "qemu/timer.h"
+#include "qemu-file.h"
 #include "migration-stats.h"
 
 MigrationAtomicStats mig_stats;
@@ -22,3 +23,43 @@ void calculate_time_since(Stat64 *val, int64_t since)
     int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
     stat64_set(val, now - since);
 }
+
+bool migration_rate_limit_exceeded(QEMUFile *f)
+{
+    if (qemu_file_get_error(f)) {
+        return true;
+    }
+
+    uint64_t rate_limit_used = stat64_get(&mig_stats.rate_limit_used);
+    uint64_t rate_limit_max = stat64_get(&mig_stats.rate_limit_max);
+    /*
+     *  rate_limit_max == 0 means no rate_limit enfoncement.
+     */
+    if (rate_limit_max > 0 && rate_limit_used > rate_limit_max) {
+        return true;
+    }
+    return false;
+}
+
+uint64_t migration_rate_limit_get(void)
+{
+    return stat64_get(&mig_stats.rate_limit_max);
+}
+
+void migration_rate_limit_set(uint64_t limit)
+{
+    /*
+     * 'limit' is per second.  But we check it each BUFER_DELAY miliseconds.
+     */
+    stat64_set(&mig_stats.rate_limit_max, limit);
+}
+
+void migration_rate_limit_reset(void)
+{
+    stat64_set(&mig_stats.rate_limit_used, 0);
+}
+
+void migration_rate_limit_account(uint64_t len)
+{
+    stat64_add(&mig_stats.rate_limit_used, len);
+}
diff --git a/migration/migration-stats.h b/migration/migration-stats.h
index 73c73d75b9..65f11ec7d1 100644
--- a/migration/migration-stats.h
+++ b/migration/migration-stats.h
@@ -69,6 +69,14 @@ typedef struct {
      * Number of bytes sent during precopy stage.
      */
     Stat64 precopy_bytes;
+    /*
+     * Maximum amount of data we can send in a cycle.
+     */
+    Stat64 rate_limit_max;
+    /*
+     * Amount of data we have sent in the current cycle.
+     */
+    Stat64 rate_limit_used;
     /*
      * How long has the setup stage took.
      */
@@ -95,4 +103,38 @@ extern MigrationAtomicStats mig_stats;
  */
 
 void calculate_time_since(Stat64 *val, int64_t since);
+
+/**
+ * migration_rate_limit_account: Increase the number of bytes transferred.
+ *
+ * Report on a number of bytes the have been transferred that need to
+ * be applied to the rate limiting calcuations.
+ *
+ * @len: amount of bytes transferred
+ */
+void migration_rate_limit_account(uint64_t len);
+
+/**
+ * migration_rate_limit_get: Get the maximum amount that can be transferred.
+ *
+ * Returns the maximum number of bytes that can be transferred in a cycle.
+ */
+uint64_t migration_rate_limit_get(void);
+
+/**
+ * migration_rate_limit_reset: Reset the rate limit counter.
+ *
+ * This is called when we know we start a new transfer cycle.
+ */
+void migration_rate_limit_reset(void);
+
+/**
+ * migration_rate_limit_set: Set the maximum amount that can be transferred.
+ *
+ * Sets the maximum amount of bytes that can be transferred in one cycle.
+ *
+ * @new_rate: new maximum amount
+ */
+void migration_rate_limit_set(uint64_t new_rate);
+
 #endif
diff --git a/migration/migration.c b/migration/migration.c
index 72286de969..370998600e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2116,7 +2116,7 @@ static int postcopy_start(MigrationState *ms)
      * will notice we're in POSTCOPY_ACTIVE and not actually
      * wrap their state up here
      */
-    qemu_file_set_rate_limit(ms->to_dst_file, bandwidth);
+    migration_rate_limit_set(bandwidth);
     if (migrate_postcopy_ram()) {
         /* Ping just for debugging, helps line traces up */
         qemu_savevm_send_ping(ms->to_dst_file, 2);
@@ -2295,7 +2295,7 @@ static void migration_completion(MigrationState *s)
             }
             if (ret >= 0) {
                 s->block_inactive = !migrate_colo();
-                qemu_file_set_rate_limit(s->to_dst_file, 0);
+                migration_rate_limit_set(0);
                 ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
                                                          s->block_inactive);
             }
@@ -2691,7 +2691,7 @@ static void migration_update_counters(MigrationState *s,
             stat64_get(&mig_stats.dirty_bytes_last_sync) / bandwidth;
     }
 
-    qemu_file_reset_rate_limit(s->to_dst_file);
+    migration_rate_limit_reset();
 
     update_iteration_initial_status(s);
 
@@ -2847,7 +2847,7 @@ bool migration_rate_limit(void)
 
     bool urgent = false;
     migration_update_counters(s, now);
-    if (qemu_file_rate_limit(s->to_dst_file)) {
+    if (migration_rate_limit_exceeded(s->to_dst_file)) {
 
         if (qemu_file_get_error(s->to_dst_file)) {
             return false;
@@ -2969,7 +2969,7 @@ static void *migration_thread(void *opaque)
     trace_migration_thread_setup_complete();
 
     while (migration_is_active(s)) {
-        if (urgent || !qemu_file_rate_limit(s->to_dst_file)) {
+        if (urgent || !migration_rate_limit_exceeded(s->to_dst_file)) {
             MigIterateState iter_state = migration_iteration_run(s);
             if (iter_state == MIG_ITERATE_SKIP) {
                 continue;
@@ -3043,7 +3043,7 @@ static void *bg_migration_thread(void *opaque)
     rcu_register_thread();
     object_ref(OBJECT(s));
 
-    qemu_file_set_rate_limit(s->to_dst_file, 0);
+    migration_rate_limit_set(0);
 
     setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
     /*
@@ -3215,7 +3215,7 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
         notifier_list_notify(&migration_state_notifiers, s);
     }
 
-    qemu_file_set_rate_limit(s->to_dst_file, rate_limit);
+    migration_rate_limit_set(rate_limit);
     qemu_file_set_blocking(s->to_dst_file, true);
 
     /*
diff --git a/migration/multifd.c b/migration/multifd.c
index 4e71c19292..2efb313be4 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -432,7 +432,7 @@ static int multifd_send_pages(QEMUFile *f)
     multifd_send_state->pages = p->pages;
     p->pages = pages;
     transferred = ((uint64_t) pages->num) * p->page_size + p->packet_len;
-    qemu_file_acct_rate_limit(f, transferred);
+    migration_rate_limit_account(transferred);
     qemu_mutex_unlock(&p->mutex);
     stat64_add(&mig_stats.transferred, transferred);
     stat64_add(&mig_stats.multifd_bytes, transferred);
diff --git a/migration/options.c b/migration/options.c
index d04b5fbc3a..a024fa3ce6 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -23,6 +23,7 @@
 #include "migration/colo.h"
 #include "migration/misc.h"
 #include "migration.h"
+#include "migration-stats.h"
 #include "qemu-file.h"
 #include "ram.h"
 #include "options.h"
@@ -1242,8 +1243,7 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
     if (params->has_max_bandwidth) {
         s->parameters.max_bandwidth = params->max_bandwidth;
         if (s->to_dst_file && !migration_in_postcopy()) {
-            qemu_file_set_rate_limit(s->to_dst_file,
-                                s->parameters.max_bandwidth);
+            migration_rate_limit_set(s->parameters.max_bandwidth);
         }
     }
 
@@ -1274,8 +1274,7 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
     if (params->has_max_postcopy_bandwidth) {
         s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth;
         if (s->to_dst_file && migration_in_postcopy()) {
-            qemu_file_set_rate_limit(s->to_dst_file,
-                    s->parameters.max_postcopy_bandwidth);
+            migration_rate_limit_set(s->parameters.max_postcopy_bandwidth);
         }
     }
     if (params->has_max_cpu_throttle) {
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 8de1ecd082..3f993e24af 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -27,6 +27,7 @@
 #include "qemu/error-report.h"
 #include "qemu/iov.h"
 #include "migration.h"
+#include "migration-stats.h"
 #include "qemu-file.h"
 #include "trace.h"
 #include "options.h"
@@ -40,17 +41,6 @@ struct QEMUFile {
     QIOChannel *ioc;
     bool is_writable;
 
-    /*
-     * Maximum amount of data in bytes to transfer during one
-     * rate limiting time window
-     */
-    uint64_t rate_limit_max;
-    /*
-     * Total amount of data in bytes queued for transfer
-     * during this rate limiting time window
-     */
-    uint64_t rate_limit_used;
-
     /* The sum of bytes transferred on the wire */
     uint64_t total_transferred;
 
@@ -302,7 +292,7 @@ void qemu_fflush(QEMUFile *f)
             qemu_file_set_error_obj(f, -EIO, local_error);
         } else {
             uint64_t size = iov_size(f->iov, f->iovcnt);
-            qemu_file_acct_rate_limit(f, size);
+            migration_rate_limit_account(size);
             f->total_transferred += size;
         }
 
@@ -355,7 +345,7 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
         int ret = f->hooks->save_page(f, block_offset,
                                       offset, size, bytes_sent);
         if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
-            qemu_file_acct_rate_limit(f, size);
+            migration_rate_limit_account(size);
         }
 
         if (ret != RAM_SAVE_CONTROL_DELAYED &&
@@ -726,43 +716,6 @@ uint64_t qemu_file_transferred(QEMUFile *f)
     return f->total_transferred;
 }
 
-int qemu_file_rate_limit(QEMUFile *f)
-{
-    if (qemu_file_get_error(f)) {
-        return 1;
-    }
-    /*
-     *  rate_limit_max == 0 means no rate_limit enfoncement.
-     */
-    if (f->rate_limit_max > 0 && f->rate_limit_used > f->rate_limit_max) {
-        return 1;
-    }
-    return 0;
-}
-
-uint64_t qemu_file_get_rate_limit(QEMUFile *f)
-{
-    return f->rate_limit_max;
-}
-
-void qemu_file_set_rate_limit(QEMUFile *f, uint64_t limit)
-{
-    /*
-     * 'limit' is per second.  But we check it each 100 miliseconds.
-     */
-    f->rate_limit_max = limit / XFER_LIMIT_RATIO;
-}
-
-void qemu_file_reset_rate_limit(QEMUFile *f)
-{
-    f->rate_limit_used = 0;
-}
-
-void qemu_file_acct_rate_limit(QEMUFile *f, uint64_t len)
-{
-    f->rate_limit_used += len;
-}
-
 void qemu_put_be16(QEMUFile *f, unsigned int v)
 {
     qemu_put_byte(f, v >> 8);
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
index ab164a58d0..46029b951c 100644
--- a/migration/qemu-file.h
+++ b/migration/qemu-file.h
@@ -129,17 +129,6 @@ void qemu_file_skip(QEMUFile *f, int size);
  * accounting information tracks the total migration traffic.
  */
 void qemu_file_credit_transfer(QEMUFile *f, size_t size);
-void qemu_file_reset_rate_limit(QEMUFile *f);
-/*
- * qemu_file_acct_rate_limit:
- *
- * Report on a number of bytes the have been transferred
- * out of band from the main file object I/O methods, and
- * need to be applied to the rate limiting calcuations
- */
-void qemu_file_acct_rate_limit(QEMUFile *f, uint64_t len);
-void qemu_file_set_rate_limit(QEMUFile *f, uint64_t new_rate);
-uint64_t qemu_file_get_rate_limit(QEMUFile *f);
 int qemu_file_get_error_obj(QEMUFile *f, Error **errp);
 int qemu_file_get_error_obj_any(QEMUFile *f1, QEMUFile *f2, Error **errp);
 void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
diff --git a/migration/ram.c b/migration/ram.c
index 5ae1fdba45..2339a99932 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3351,7 +3351,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
 
         t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
         i = 0;
-        while ((ret = qemu_file_rate_limit(f)) == 0 ||
+        while ((ret = migration_rate_limit_exceeded(f)) == 0 ||
                postcopy_has_request(rs)) {
             int pages;
 
diff --git a/migration/savevm.c b/migration/savevm.c
index c7af9050c2..376118bc98 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1345,7 +1345,7 @@ int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
             !(se->ops->has_postcopy && se->ops->has_postcopy(se->opaque))) {
             continue;
         }
-        if (qemu_file_rate_limit(f)) {
+        if (migration_rate_limit_exceeded(f)) {
             return 0;
         }
         trace_savevm_section_start(se->idstr, se->section_id);
-- 
2.40.0

On 5/8/23 15:08, Juan Quintela wrote:
> This way we can make them atomic and use this functions from any
> place.  I also moved all functions that use rate_limit to
> migration-stats.
> 
> Functions got renamed, they are not qemu_file anymore.
> 
> qemu_file_rate_limit -> migration_rate_limit_exceeded
> qemu_file_set_rate_limit -> migration_rate_limit_set
> qemu_file_get_rate_limit -> migration_rate_limit_get
> qemu_file_reset_rate_limit -> migration_rate_limit_reset
> qemu_file_acct_rate_limit -> migration_rate_limit_account.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> ---
> 
> If you have any good suggestion for better names, I am all ears.

May be :

  qemu_file_rate_limit -> migration_rate_limit_is_exceeded
  qemu_file_acct_rate_limit -> migration_rate_limit_inc


Also, migration_rate_limit() would need some prefix to understand what is
its purpose.

Do we really need "_limit" in the names ?

Thanks,

C.

> ---
>   hw/ppc/spapr.c                      |  5 +--
>   hw/s390x/s390-stattrib.c            |  2 +-
>   include/migration/qemu-file-types.h |  2 +-
>   migration/block-dirty-bitmap.c      |  2 +-
>   migration/block.c                   |  5 +--
>   migration/migration-stats.c         | 41 ++++++++++++++++++++++
>   migration/migration-stats.h         | 42 +++++++++++++++++++++++
>   migration/migration.c               | 14 ++++----
>   migration/multifd.c                 |  2 +-
>   migration/options.c                 |  7 ++--
>   migration/qemu-file.c               | 53 ++---------------------------
>   migration/qemu-file.h               | 11 ------
>   migration/ram.c                     |  2 +-
>   migration/savevm.c                  |  2 +-
>   14 files changed, 108 insertions(+), 82 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index ddc9c7b1a1..dbd2753278 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2166,7 +2166,7 @@ static void htab_save_first_pass(QEMUFile *f, SpaprMachineState *spapr,
>                   break;
>               }
>           }
> -    } while ((index < htabslots) && !qemu_file_rate_limit(f));
> +    } while ((index < htabslots) && !migration_rate_limit_exceeded(f));
>   
>       if (index >= htabslots) {
>           assert(index == htabslots);
> @@ -2237,7 +2237,8 @@ static int htab_save_later_pass(QEMUFile *f, SpaprMachineState *spapr,
>               assert(index == htabslots);
>               index = 0;
>           }
> -    } while ((examined < htabslots) && (!qemu_file_rate_limit(f) || final));
> +    } while ((examined < htabslots) &&
> +             (!migration_rate_limit_exceeded(f) || final));
>   
>       if (index >= htabslots) {
>           assert(index == htabslots);
> diff --git a/hw/s390x/s390-stattrib.c b/hw/s390x/s390-stattrib.c
> index aed919ad7d..fb0a20f2e1 100644
> --- a/hw/s390x/s390-stattrib.c
> +++ b/hw/s390x/s390-stattrib.c
> @@ -209,7 +209,7 @@ static int cmma_save(QEMUFile *f, void *opaque, int final)
>           return -ENOMEM;
>       }
>   
> -    while (final ? 1 : qemu_file_rate_limit(f) == 0) {
> +    while (final ? 1 : migration_rate_limit_exceeded(f) == 0) {
>           reallen = sac->get_stattr(sas, &start_gfn, buflen, buf);
>           if (reallen < 0) {
>               g_free(buf);
> diff --git a/include/migration/qemu-file-types.h b/include/migration/qemu-file-types.h
> index 1436f9ce92..0354f45198 100644
> --- a/include/migration/qemu-file-types.h
> +++ b/include/migration/qemu-file-types.h
> @@ -165,6 +165,6 @@ size_t coroutine_mixed_fn qemu_get_counted_string(QEMUFile *f, char buf[256]);
>   
>   void qemu_put_counted_string(QEMUFile *f, const char *name);
>   
> -int qemu_file_rate_limit(QEMUFile *f);
> +bool migration_rate_limit_exceeded(QEMUFile *f);
>   
>   #endif
> diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
> index 20f36e6bd8..a815678926 100644
> --- a/migration/block-dirty-bitmap.c
> +++ b/migration/block-dirty-bitmap.c
> @@ -706,7 +706,7 @@ static void bulk_phase(QEMUFile *f, DBMSaveState *s, bool limit)
>       QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
>           while (!dbms->bulk_completed) {
>               bulk_phase_send_chunk(f, s, dbms);
> -            if (limit && qemu_file_rate_limit(f)) {
> +            if (limit && migration_rate_limit_exceeded(f)) {
>                   return;
>               }
>           }
> diff --git a/migration/block.c b/migration/block.c
> index 12617b4152..fc1caa9ca6 100644
> --- a/migration/block.c
> +++ b/migration/block.c
> @@ -23,6 +23,7 @@
>   #include "block/dirty-bitmap.h"
>   #include "migration/misc.h"
>   #include "migration.h"
> +#include "migration-stats.h"
>   #include "migration/register.h"
>   #include "qemu-file.h"
>   #include "migration/vmstate.h"
> @@ -625,7 +626,7 @@ static int flush_blks(QEMUFile *f)
>   
>       blk_mig_lock();
>       while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
> -        if (qemu_file_rate_limit(f)) {
> +        if (migration_rate_limit_exceeded(f)) {
>               break;
>           }
>           if (blk->ret < 0) {
> @@ -762,7 +763,7 @@ static int block_save_iterate(QEMUFile *f, void *opaque)
>       /* control the rate of transfer */
>       blk_mig_lock();
>       while (block_mig_state.read_done * BLK_MIG_BLOCK_SIZE <
> -           qemu_file_get_rate_limit(f) &&
> +           migration_rate_limit_get() &&
>              block_mig_state.submitted < MAX_PARALLEL_IO &&
>              (block_mig_state.submitted + block_mig_state.read_done) <
>              MAX_IO_BUFFERS) {
> diff --git a/migration/migration-stats.c b/migration/migration-stats.c
> index 5278c6c821..e01842cabc 100644
> --- a/migration/migration-stats.c
> +++ b/migration/migration-stats.c
> @@ -13,6 +13,7 @@
>   #include "qemu/osdep.h"
>   #include "qemu/stats64.h"
>   #include "qemu/timer.h"
> +#include "qemu-file.h"
>   #include "migration-stats.h"
>   
>   MigrationAtomicStats mig_stats;
> @@ -22,3 +23,43 @@ void calculate_time_since(Stat64 *val, int64_t since)
>       int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
>       stat64_set(val, now - since);
>   }
> +
> +bool migration_rate_limit_exceeded(QEMUFile *f)
> +{
> +    if (qemu_file_get_error(f)) {
> +        return true;
> +    }
> +
> +    uint64_t rate_limit_used = stat64_get(&mig_stats.rate_limit_used);
> +    uint64_t rate_limit_max = stat64_get(&mig_stats.rate_limit_max);
> +    /*
> +     *  rate_limit_max == 0 means no rate_limit enfoncement.
> +     */
> +    if (rate_limit_max > 0 && rate_limit_used > rate_limit_max) {
> +        return true;
> +    }
> +    return false;
> +}
> +
> +uint64_t migration_rate_limit_get(void)
> +{
> +    return stat64_get(&mig_stats.rate_limit_max);
> +}
> +
> +void migration_rate_limit_set(uint64_t limit)
> +{
> +    /*
> +     * 'limit' is per second.  But we check it each BUFER_DELAY miliseconds.
> +     */
> +    stat64_set(&mig_stats.rate_limit_max, limit);
> +}
> +
> +void migration_rate_limit_reset(void)
> +{
> +    stat64_set(&mig_stats.rate_limit_used, 0);
> +}
> +
> +void migration_rate_limit_account(uint64_t len)
> +{
> +    stat64_add(&mig_stats.rate_limit_used, len);
> +}
> diff --git a/migration/migration-stats.h b/migration/migration-stats.h
> index 73c73d75b9..65f11ec7d1 100644
> --- a/migration/migration-stats.h
> +++ b/migration/migration-stats.h
> @@ -69,6 +69,14 @@ typedef struct {
>        * Number of bytes sent during precopy stage.
>        */
>       Stat64 precopy_bytes;
> +    /*
> +     * Maximum amount of data we can send in a cycle.
> +     */
> +    Stat64 rate_limit_max;
> +    /*
> +     * Amount of data we have sent in the current cycle.
> +     */
> +    Stat64 rate_limit_used;
>       /*
>        * How long has the setup stage took.
>        */
> @@ -95,4 +103,38 @@ extern MigrationAtomicStats mig_stats;
>    */
>   
>   void calculate_time_since(Stat64 *val, int64_t since);
> +
> +/**
> + * migration_rate_limit_account: Increase the number of bytes transferred.
> + *
> + * Report on a number of bytes the have been transferred that need to
> + * be applied to the rate limiting calcuations.
> + *
> + * @len: amount of bytes transferred
> + */
> +void migration_rate_limit_account(uint64_t len);
> +
> +/**
> + * migration_rate_limit_get: Get the maximum amount that can be transferred.
> + *
> + * Returns the maximum number of bytes that can be transferred in a cycle.
> + */
> +uint64_t migration_rate_limit_get(void);
> +
> +/**
> + * migration_rate_limit_reset: Reset the rate limit counter.
> + *
> + * This is called when we know we start a new transfer cycle.
> + */
> +void migration_rate_limit_reset(void);
> +
> +/**
> + * migration_rate_limit_set: Set the maximum amount that can be transferred.
> + *
> + * Sets the maximum amount of bytes that can be transferred in one cycle.
> + *
> + * @new_rate: new maximum amount
> + */
> +void migration_rate_limit_set(uint64_t new_rate);
> +
>   #endif
> diff --git a/migration/migration.c b/migration/migration.c
> index 72286de969..370998600e 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -2116,7 +2116,7 @@ static int postcopy_start(MigrationState *ms)
>        * will notice we're in POSTCOPY_ACTIVE and not actually
>        * wrap their state up here
>        */
> -    qemu_file_set_rate_limit(ms->to_dst_file, bandwidth);
> +    migration_rate_limit_set(bandwidth);
>       if (migrate_postcopy_ram()) {
>           /* Ping just for debugging, helps line traces up */
>           qemu_savevm_send_ping(ms->to_dst_file, 2);
> @@ -2295,7 +2295,7 @@ static void migration_completion(MigrationState *s)
>               }
>               if (ret >= 0) {
>                   s->block_inactive = !migrate_colo();
> -                qemu_file_set_rate_limit(s->to_dst_file, 0);
> +                migration_rate_limit_set(0);
>                   ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
>                                                            s->block_inactive);
>               }
> @@ -2691,7 +2691,7 @@ static void migration_update_counters(MigrationState *s,
>               stat64_get(&mig_stats.dirty_bytes_last_sync) / bandwidth;
>       }
>   
> -    qemu_file_reset_rate_limit(s->to_dst_file);
> +    migration_rate_limit_reset();
>   
>       update_iteration_initial_status(s);
>   
> @@ -2847,7 +2847,7 @@ bool migration_rate_limit(void)
>   
>       bool urgent = false;
>       migration_update_counters(s, now);
> -    if (qemu_file_rate_limit(s->to_dst_file)) {
> +    if (migration_rate_limit_exceeded(s->to_dst_file)) {
>   
>           if (qemu_file_get_error(s->to_dst_file)) {
>               return false;
> @@ -2969,7 +2969,7 @@ static void *migration_thread(void *opaque)
>       trace_migration_thread_setup_complete();
>   
>       while (migration_is_active(s)) {
> -        if (urgent || !qemu_file_rate_limit(s->to_dst_file)) {
> +        if (urgent || !migration_rate_limit_exceeded(s->to_dst_file)) {
>               MigIterateState iter_state = migration_iteration_run(s);
>               if (iter_state == MIG_ITERATE_SKIP) {
>                   continue;
> @@ -3043,7 +3043,7 @@ static void *bg_migration_thread(void *opaque)
>       rcu_register_thread();
>       object_ref(OBJECT(s));
>   
> -    qemu_file_set_rate_limit(s->to_dst_file, 0);
> +    migration_rate_limit_set(0);
>   
>       setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
>       /*
> @@ -3215,7 +3215,7 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
>           notifier_list_notify(&migration_state_notifiers, s);
>       }
>   
> -    qemu_file_set_rate_limit(s->to_dst_file, rate_limit);
> +    migration_rate_limit_set(rate_limit);
>       qemu_file_set_blocking(s->to_dst_file, true);
>   
>       /*
> diff --git a/migration/multifd.c b/migration/multifd.c
> index 4e71c19292..2efb313be4 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -432,7 +432,7 @@ static int multifd_send_pages(QEMUFile *f)
>       multifd_send_state->pages = p->pages;
>       p->pages = pages;
>       transferred = ((uint64_t) pages->num) * p->page_size + p->packet_len;
> -    qemu_file_acct_rate_limit(f, transferred);
> +    migration_rate_limit_account(transferred);
>       qemu_mutex_unlock(&p->mutex);
>       stat64_add(&mig_stats.transferred, transferred);
>       stat64_add(&mig_stats.multifd_bytes, transferred);
> diff --git a/migration/options.c b/migration/options.c
> index d04b5fbc3a..a024fa3ce6 100644
> --- a/migration/options.c
> +++ b/migration/options.c
> @@ -23,6 +23,7 @@
>   #include "migration/colo.h"
>   #include "migration/misc.h"
>   #include "migration.h"
> +#include "migration-stats.h"
>   #include "qemu-file.h"
>   #include "ram.h"
>   #include "options.h"
> @@ -1242,8 +1243,7 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
>       if (params->has_max_bandwidth) {
>           s->parameters.max_bandwidth = params->max_bandwidth;
>           if (s->to_dst_file && !migration_in_postcopy()) {
> -            qemu_file_set_rate_limit(s->to_dst_file,
> -                                s->parameters.max_bandwidth);
> +            migration_rate_limit_set(s->parameters.max_bandwidth);
>           }
>       }
>   
> @@ -1274,8 +1274,7 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
>       if (params->has_max_postcopy_bandwidth) {
>           s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth;
>           if (s->to_dst_file && migration_in_postcopy()) {
> -            qemu_file_set_rate_limit(s->to_dst_file,
> -                    s->parameters.max_postcopy_bandwidth);
> +            migration_rate_limit_set(s->parameters.max_postcopy_bandwidth);
>           }
>       }
>       if (params->has_max_cpu_throttle) {
> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> index 8de1ecd082..3f993e24af 100644
> --- a/migration/qemu-file.c
> +++ b/migration/qemu-file.c
> @@ -27,6 +27,7 @@
>   #include "qemu/error-report.h"
>   #include "qemu/iov.h"
>   #include "migration.h"
> +#include "migration-stats.h"
>   #include "qemu-file.h"
>   #include "trace.h"
>   #include "options.h"
> @@ -40,17 +41,6 @@ struct QEMUFile {
>       QIOChannel *ioc;
>       bool is_writable;
>   
> -    /*
> -     * Maximum amount of data in bytes to transfer during one
> -     * rate limiting time window
> -     */
> -    uint64_t rate_limit_max;
> -    /*
> -     * Total amount of data in bytes queued for transfer
> -     * during this rate limiting time window
> -     */
> -    uint64_t rate_limit_used;
> -
>       /* The sum of bytes transferred on the wire */
>       uint64_t total_transferred;
>   
> @@ -302,7 +292,7 @@ void qemu_fflush(QEMUFile *f)
>               qemu_file_set_error_obj(f, -EIO, local_error);
>           } else {
>               uint64_t size = iov_size(f->iov, f->iovcnt);
> -            qemu_file_acct_rate_limit(f, size);
> +            migration_rate_limit_account(size);
>               f->total_transferred += size;
>           }
>   
> @@ -355,7 +345,7 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
>           int ret = f->hooks->save_page(f, block_offset,
>                                         offset, size, bytes_sent);
>           if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
> -            qemu_file_acct_rate_limit(f, size);
> +            migration_rate_limit_account(size);
>           }
>   
>           if (ret != RAM_SAVE_CONTROL_DELAYED &&
> @@ -726,43 +716,6 @@ uint64_t qemu_file_transferred(QEMUFile *f)
>       return f->total_transferred;
>   }
>   
> -int qemu_file_rate_limit(QEMUFile *f)
> -{
> -    if (qemu_file_get_error(f)) {
> -        return 1;
> -    }
> -    /*
> -     *  rate_limit_max == 0 means no rate_limit enfoncement.
> -     */
> -    if (f->rate_limit_max > 0 && f->rate_limit_used > f->rate_limit_max) {
> -        return 1;
> -    }
> -    return 0;
> -}
> -
> -uint64_t qemu_file_get_rate_limit(QEMUFile *f)
> -{
> -    return f->rate_limit_max;
> -}
> -
> -void qemu_file_set_rate_limit(QEMUFile *f, uint64_t limit)
> -{
> -    /*
> -     * 'limit' is per second.  But we check it each 100 miliseconds.
> -     */
> -    f->rate_limit_max = limit / XFER_LIMIT_RATIO;
> -}
> -
> -void qemu_file_reset_rate_limit(QEMUFile *f)
> -{
> -    f->rate_limit_used = 0;
> -}
> -
> -void qemu_file_acct_rate_limit(QEMUFile *f, uint64_t len)
> -{
> -    f->rate_limit_used += len;
> -}
> -
>   void qemu_put_be16(QEMUFile *f, unsigned int v)
>   {
>       qemu_put_byte(f, v >> 8);
> diff --git a/migration/qemu-file.h b/migration/qemu-file.h
> index ab164a58d0..46029b951c 100644
> --- a/migration/qemu-file.h
> +++ b/migration/qemu-file.h
> @@ -129,17 +129,6 @@ void qemu_file_skip(QEMUFile *f, int size);
>    * accounting information tracks the total migration traffic.
>    */
>   void qemu_file_credit_transfer(QEMUFile *f, size_t size);
> -void qemu_file_reset_rate_limit(QEMUFile *f);
> -/*
> - * qemu_file_acct_rate_limit:
> - *
> - * Report on a number of bytes the have been transferred
> - * out of band from the main file object I/O methods, and
> - * need to be applied to the rate limiting calcuations
> - */
> -void qemu_file_acct_rate_limit(QEMUFile *f, uint64_t len);
> -void qemu_file_set_rate_limit(QEMUFile *f, uint64_t new_rate);
> -uint64_t qemu_file_get_rate_limit(QEMUFile *f);
>   int qemu_file_get_error_obj(QEMUFile *f, Error **errp);
>   int qemu_file_get_error_obj_any(QEMUFile *f1, QEMUFile *f2, Error **errp);
>   void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
> diff --git a/migration/ram.c b/migration/ram.c
> index 5ae1fdba45..2339a99932 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -3351,7 +3351,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
>   
>           t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
>           i = 0;
> -        while ((ret = qemu_file_rate_limit(f)) == 0 ||
> +        while ((ret = migration_rate_limit_exceeded(f)) == 0 ||
>                  postcopy_has_request(rs)) {
>               int pages;
>   
> diff --git a/migration/savevm.c b/migration/savevm.c
> index c7af9050c2..376118bc98 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1345,7 +1345,7 @@ int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
>               !(se->ops->has_postcopy && se->ops->has_postcopy(se->opaque))) {
>               continue;
>           }
> -        if (qemu_file_rate_limit(f)) {
> +        if (migration_rate_limit_exceeded(f)) {
>               return 0;
>           }
>           trace_savevm_section_start(se->idstr, se->section_id);

Cédric Le Goater <clg@kaod.org> wrote:
> On 5/8/23 15:08, Juan Quintela wrote:
>> This way we can make them atomic and use this functions from any
>> place.  I also moved all functions that use rate_limit to
>> migration-stats.
>> Functions got renamed, they are not qemu_file anymore.
>> qemu_file_rate_limit -> migration_rate_limit_exceeded
>> qemu_file_set_rate_limit -> migration_rate_limit_set
>> qemu_file_get_rate_limit -> migration_rate_limit_get
>> qemu_file_reset_rate_limit -> migration_rate_limit_reset
>> qemu_file_acct_rate_limit -> migration_rate_limit_account.
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> ---
>> If you have any good suggestion for better names, I am all ears.
>
> May be :
>
>  qemu_file_rate_limit -> migration_rate_limit_is_exceeded

I try not to put _is_ in function names.  If it needs to be there, I
think that I need to rename the functino.

migration_rate_limit_exceeded()

seems clear to me.


>  qemu_file_acct_rate_limit -> migration_rate_limit_inc

My problem for this one is that we are not increasing the rate_limit, we
are "decreasing" the amount of data we have for this period.  That is
why I thought about _account(), but who knows.


> Also, migration_rate_limit() would need some prefix to understand what is
> its purpose.

What do you mean here?
This is the only rate_limit that I can think in migration.

> Do we really need "_limit" in the names ?

You have a point here.

If nobody complains/suggest anything else, I will drop the _limit for
the next submission.

Thanks very much.

On 5/15/23 15:09, Juan Quintela wrote:
> Cédric Le Goater <clg@kaod.org> wrote:
>> On 5/8/23 15:08, Juan Quintela wrote:
>>> This way we can make them atomic and use this functions from any
>>> place.  I also moved all functions that use rate_limit to
>>> migration-stats.
>>> Functions got renamed, they are not qemu_file anymore.
>>> qemu_file_rate_limit -> migration_rate_limit_exceeded
>>> qemu_file_set_rate_limit -> migration_rate_limit_set
>>> qemu_file_get_rate_limit -> migration_rate_limit_get
>>> qemu_file_reset_rate_limit -> migration_rate_limit_reset
>>> qemu_file_acct_rate_limit -> migration_rate_limit_account.
>>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>>> ---
>>> If you have any good suggestion for better names, I am all ears.
>>
>> May be :
>>
>>   qemu_file_rate_limit -> migration_rate_limit_is_exceeded
> 
> I try not to put _is_ in function names.  If it needs to be there, I
> think that I need to rename the functino.

It is common practice for functions doing a simple test and returning a bool.
No big deal anyway.
  
> migration_rate_limit_exceeded()
> 
> seems clear to me.
> 
>>   qemu_file_acct_rate_limit -> migration_rate_limit_inc
> 
> My problem for this one is that we are not increasing the rate_limit, we
> are "decreasing" the amount of data we have for this period.  That is
> why I thought about _account(), but who knows.
> 
> 
>> Also, migration_rate_limit() would need some prefix to understand what is
>> its purpose.
> 
> What do you mean here?

I am referring to :

   /* Returns true if the rate limiting was broken by an urgent request */
   bool migration_rate_limit(void)
   {
       ...
       return urgent;
   }

which existed prior to the name changes and I thought migration_rate_limit()
would suffer the same fate. May be keep the '_limit' suffix for this one if
you remove it for the others ?

Thanks,

C.


> This is the only rate_limit that I can think in migration.
> 
>> Do we really need "_limit" in the names ?
> 
> You have a point here.
> 
> If nobody complains/suggest anything else, I will drop the _limit for
> the next submission.
> 
> Thanks very much.
> 

Cédric Le Goater <clg@kaod.org> wrote:
> On 5/15/23 15:09, Juan Quintela wrote:
>> Cédric Le Goater <clg@kaod.org> wrote:
>>> On 5/8/23 15:08, Juan Quintela wrote:
>>>> This way we can make them atomic and use this functions from any
>>>> place.  I also moved all functions that use rate_limit to
>>>> migration-stats.
>>>> Functions got renamed, they are not qemu_file anymore.
>>>> qemu_file_rate_limit -> migration_rate_limit_exceeded
>>>> qemu_file_set_rate_limit -> migration_rate_limit_set
>>>> qemu_file_get_rate_limit -> migration_rate_limit_get
>>>> qemu_file_reset_rate_limit -> migration_rate_limit_reset
>>>> qemu_file_acct_rate_limit -> migration_rate_limit_account.
>>>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>>>> ---
>>>> If you have any good suggestion for better names, I am all ears.
>>>
>>> May be :
>>>
>>>   qemu_file_rate_limit -> migration_rate_limit_is_exceeded
>> I try not to put _is_ in function names.  If it needs to be there, I
>> think that I need to rename the functino.
>
> It is common practice for functions doing a simple test and returning a bool.
> No big deal anyway.
>  > migration_rate_limit_exceeded()
>> seems clear to me.
>> 
>>>   qemu_file_acct_rate_limit -> migration_rate_limit_inc
>> My problem for this one is that we are not increasing the
>> rate_limit, we
>> are "decreasing" the amount of data we have for this period.  That is
>> why I thought about _account(), but who knows.
>> 
>>> Also, migration_rate_limit() would need some prefix to understand what is
>>> its purpose.
>> What do you mean here?
>
> I am referring to :
>
>   /* Returns true if the rate limiting was broken by an urgent request */
>   bool migration_rate_limit(void)
>   {
>       ...
>       return urgent;
>   }

out of ideas:

migration_rate_wait()
- the good
  *we wait if we have to
- the bad
  we can be interrupted if there is anything urgent
  we only wait if counters says that we have to

migration_rate_check()
* we always check
* we return a value consistent with checking
* but we check if we have to wait, not if there is anythying urgent

I am leaving it with migration_rate_limit() name until someone cames
with a better one.  It is not worse than what we have in.


>
> which existed prior to the name changes and I thought migration_rate_limit()
> would suffer the same fate. May be keep the '_limit' suffix for this one if
> you remove it for the others ?

I am no sure if migration_rate() is better than migration_rate_limit().

Later, Juan.

Cédric Le Goater <clg@kaod.org> wrote:
> On 5/15/23 15:09, Juan Quintela wrote:
>> Cédric Le Goater <clg@kaod.org> wrote:
>>> On 5/8/23 15:08, Juan Quintela wrote:
>>>> This way we can make them atomic and use this functions from any
>>>> place.  I also moved all functions that use rate_limit to
>>>> migration-stats.
>>>> Functions got renamed, they are not qemu_file anymore.
>>>> qemu_file_rate_limit -> migration_rate_limit_exceeded
>>>> qemu_file_set_rate_limit -> migration_rate_limit_set
>>>> qemu_file_get_rate_limit -> migration_rate_limit_get
>>>> qemu_file_reset_rate_limit -> migration_rate_limit_reset
>>>> qemu_file_acct_rate_limit -> migration_rate_limit_account.
>>>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>>>> ---
>>>> If you have any good suggestion for better names, I am all ears.
>>>
>>> May be :
>>>
>>>   qemu_file_rate_limit -> migration_rate_limit_is_exceeded
>> I try not to put _is_ in function names.  If it needs to be there, I
>> think that I need to rename the functino.
>
> It is common practice for functions doing a simple test and returning a bool.
> No big deal anyway.
>  > migration_rate_limit_exceeded()
>> seems clear to me.
>> 
>>>   qemu_file_acct_rate_limit -> migration_rate_limit_inc
>> My problem for this one is that we are not increasing the
>> rate_limit, we
>> are "decreasing" the amount of data we have for this period.  That is
>> why I thought about _account(), but who knows.
>> 
>>> Also, migration_rate_limit() would need some prefix to understand what is
>>> its purpose.
>> What do you mean here?
>
> I am referring to :
>
>   /* Returns true if the rate limiting was broken by an urgent request */
>   bool migration_rate_limit(void)
>   {
>       ...
>       return urgent;
>   }
>
> which existed prior to the name changes and I thought migration_rate_limit()
> would suffer the same fate. May be keep the '_limit' suffix for this one if
> you remove it for the others ?

ok, will think about this one.

Later, Juan.

On 5/8/23 18:38, Juan Quintela wrote:
> This way we can make them atomic and use this functions from any

s/this/these

> place.  I also moved all functions that use rate_limit to
> migration-stats.
> 
> Functions got renamed, they are not qemu_file anymore.
> 
> qemu_file_rate_limit -> migration_rate_limit_exceeded
> qemu_file_set_rate_limit -> migration_rate_limit_set
> qemu_file_get_rate_limit -> migration_rate_limit_get
> qemu_file_reset_rate_limit -> migration_rate_limit_reset
> qemu_file_acct_rate_limit -> migration_rate_limit_account.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> ---
> 
> If you have any good suggestion for better names, I am all ears.
> ---
>   hw/ppc/spapr.c                      |  5 +--
>   hw/s390x/s390-stattrib.c            |  2 +-
>   include/migration/qemu-file-types.h |  2 +-
>   migration/block-dirty-bitmap.c      |  2 +-
>   migration/block.c                   |  5 +--
>   migration/migration-stats.c         | 41 ++++++++++++++++++++++
>   migration/migration-stats.h         | 42 +++++++++++++++++++++++
>   migration/migration.c               | 14 ++++----
>   migration/multifd.c                 |  2 +-
>   migration/options.c                 |  7 ++--
>   migration/qemu-file.c               | 53 ++---------------------------
>   migration/qemu-file.h               | 11 ------
>   migration/ram.c                     |  2 +-
>   migration/savevm.c                  |  2 +-
>   14 files changed, 108 insertions(+), 82 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index ddc9c7b1a1..dbd2753278 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2166,7 +2166,7 @@ static void htab_save_first_pass(QEMUFile *f, SpaprMachineState *spapr,
>                   break;
>               }
>           }
> -    } while ((index < htabslots) && !qemu_file_rate_limit(f));
> +    } while ((index < htabslots) && !migration_rate_limit_exceeded(f));
>   
>       if (index >= htabslots) {
>           assert(index == htabslots);
> @@ -2237,7 +2237,8 @@ static int htab_save_later_pass(QEMUFile *f, SpaprMachineState *spapr,
>               assert(index == htabslots);
>               index = 0;
>           }
> -    } while ((examined < htabslots) && (!qemu_file_rate_limit(f) || final));
> +    } while ((examined < htabslots) &&
> +             (!migration_rate_limit_exceeded(f) || final));
>   
>       if (index >= htabslots) {
>           assert(index == htabslots);
> diff --git a/hw/s390x/s390-stattrib.c b/hw/s390x/s390-stattrib.c
> index aed919ad7d..fb0a20f2e1 100644
> --- a/hw/s390x/s390-stattrib.c
> +++ b/hw/s390x/s390-stattrib.c
> @@ -209,7 +209,7 @@ static int cmma_save(QEMUFile *f, void *opaque, int final)
>           return -ENOMEM;
>       }
>   
> -    while (final ? 1 : qemu_file_rate_limit(f) == 0) {
> +    while (final ? 1 : migration_rate_limit_exceeded(f) == 0) {
        while (final ? 1 : !migration_rate_limit_exceeded(f)) {
>           reallen = sac->get_stattr(sas, &start_gfn, buflen, buf);
>           if (reallen < 0) {
>               g_free(buf);
> diff --git a/include/migration/qemu-file-types.h b/include/migration/qemu-file-types.h
> index 1436f9ce92..0354f45198 100644
> --- a/include/migration/qemu-file-types.h
> +++ b/include/migration/qemu-file-types.h
> @@ -165,6 +165,6 @@ size_t coroutine_mixed_fn qemu_get_counted_string(QEMUFile *f, char buf[256]);
>   
>   void qemu_put_counted_string(QEMUFile *f, const char *name);
>   
> -int qemu_file_rate_limit(QEMUFile *f);
> +bool migration_rate_limit_exceeded(QEMUFile *f);
> return type is also getting changed, could be mentioned in commit log.

>   #endif
> diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
> index 20f36e6bd8..a815678926 100644
> --- a/migration/block-dirty-bitmap.c
> +++ b/migration/block-dirty-bitmap.c
> @@ -706,7 +706,7 @@ static void bulk_phase(QEMUFile *f, DBMSaveState *s, bool limit)
>       QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
>           while (!dbms->bulk_completed) {
>               bulk_phase_send_chunk(f, s, dbms);
> -            if (limit && qemu_file_rate_limit(f)) {
> +            if (limit && migration_rate_limit_exceeded(f)) {
>                   return;
>               }
>           }
> diff --git a/migration/block.c b/migration/block.c
> index 12617b4152..fc1caa9ca6 100644
> --- a/migration/block.c
> +++ b/migration/block.c
> @@ -23,6 +23,7 @@
>   #include "block/dirty-bitmap.h"
>   #include "migration/misc.h"
>   #include "migration.h"
> +#include "migration-stats.h"
>   #include "migration/register.h"
>   #include "qemu-file.h"
>   #include "migration/vmstate.h"
> @@ -625,7 +626,7 @@ static int flush_blks(QEMUFile *f)
>   
>       blk_mig_lock();
>       while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
> -        if (qemu_file_rate_limit(f)) {
> +        if (migration_rate_limit_exceeded(f)) {
>               break;
>           }
>           if (blk->ret < 0) {
> @@ -762,7 +763,7 @@ static int block_save_iterate(QEMUFile *f, void *opaque)
>       /* control the rate of transfer */
>       blk_mig_lock();
>       while (block_mig_state.read_done * BLK_MIG_BLOCK_SIZE <
> -           qemu_file_get_rate_limit(f) &&
> +           migration_rate_limit_get() &&
>              block_mig_state.submitted < MAX_PARALLEL_IO &&
>              (block_mig_state.submitted + block_mig_state.read_done) <
>              MAX_IO_BUFFERS) {
> diff --git a/migration/migration-stats.c b/migration/migration-stats.c
> index 5278c6c821..e01842cabc 100644
> --- a/migration/migration-stats.c
> +++ b/migration/migration-stats.c
> @@ -13,6 +13,7 @@
>   #include "qemu/osdep.h"
>   #include "qemu/stats64.h"
>   #include "qemu/timer.h"
> +#include "qemu-file.h"
>   #include "migration-stats.h"
>   
>   MigrationAtomicStats mig_stats;
> @@ -22,3 +23,43 @@ void calculate_time_since(Stat64 *val, int64_t since)
>       int64_t now = qemu_clock_get_ms(QEMU_CLOCK_HOST);
>       stat64_set(val, now - since);
>   }
> +
> +bool migration_rate_limit_exceeded(QEMUFile *f)
> +{
> +    if (qemu_file_get_error(f)) {
> +        return true;
> +    }
> +
> +    uint64_t rate_limit_used = stat64_get(&mig_stats.rate_limit_used);
> +    uint64_t rate_limit_max = stat64_get(&mig_stats.rate_limit_max);
> +    /*
> +     *  rate_limit_max == 0 means no rate_limit enfoncement.
> +     */
> +    if (rate_limit_max > 0 && rate_limit_used > rate_limit_max) {
> +        return true;
> +    }
> +    return false;
> +}
> +
> +uint64_t migration_rate_limit_get(void)
> +{
> +    return stat64_get(&mig_stats.rate_limit_max);
> +}
> +
> +void migration_rate_limit_set(uint64_t limit)
> +{
> +    /*
> +     * 'limit' is per second.  But we check it each BUFER_DELAY miliseconds.
> +     */
> +    stat64_set(&mig_stats.rate_limit_max, limit);
> +}
> +
> +void migration_rate_limit_reset(void)
> +{
> +    stat64_set(&mig_stats.rate_limit_used, 0);
> +}
> +
> +void migration_rate_limit_account(uint64_t len)
> +{
> +    stat64_add(&mig_stats.rate_limit_used, len);
> +}
> diff --git a/migration/migration-stats.h b/migration/migration-stats.h
> index 73c73d75b9..65f11ec7d1 100644
> --- a/migration/migration-stats.h
> +++ b/migration/migration-stats.h
> @@ -69,6 +69,14 @@ typedef struct {
>        * Number of bytes sent during precopy stage.
>        */
>       Stat64 precopy_bytes;
> +    /*
> +     * Maximum amount of data we can send in a cycle.
> +     */
> +    Stat64 rate_limit_max;
> +    /*
> +     * Amount of data we have sent in the current cycle.
> +     */
> +    Stat64 rate_limit_used;
>       /*
>        * How long has the setup stage took.
>        */
> @@ -95,4 +103,38 @@ extern MigrationAtomicStats mig_stats;
>    */
>   
>   void calculate_time_since(Stat64 *val, int64_t since);
> +
> +/**
> + * migration_rate_limit_account: Increase the number of bytes transferred.
> + *
> + * Report on a number of bytes the have been transferred that need to
> + * be applied to the rate limiting calcuations.
> + *
> + * @len: amount of bytes transferred
> + */
> +void migration_rate_limit_account(uint64_t len);
> +
> +/**
> + * migration_rate_limit_get: Get the maximum amount that can be transferred.
> + *
> + * Returns the maximum number of bytes that can be transferred in a cycle.
> + */
> +uint64_t migration_rate_limit_get(void);
> +
> +/**
> + * migration_rate_limit_reset: Reset the rate limit counter.
> + *
> + * This is called when we know we start a new transfer cycle.
> + */
> +void migration_rate_limit_reset(void);
> +
> +/**
> + * migration_rate_limit_set: Set the maximum amount that can be transferred.
> + *
> + * Sets the maximum amount of bytes that can be transferred in one cycle.
> + *
> + * @new_rate: new maximum amount
> + */
> +void migration_rate_limit_set(uint64_t new_rate);
> +
>   #endif
> diff --git a/migration/migration.c b/migration/migration.c
> index 72286de969..370998600e 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -2116,7 +2116,7 @@ static int postcopy_start(MigrationState *ms)
>        * will notice we're in POSTCOPY_ACTIVE and not actually
>        * wrap their state up here
>        */
> -    qemu_file_set_rate_limit(ms->to_dst_file, bandwidth);
> +    migration_rate_limit_set(bandwidth);
>       if (migrate_postcopy_ram()) {
>           /* Ping just for debugging, helps line traces up */
>           qemu_savevm_send_ping(ms->to_dst_file, 2);
> @@ -2295,7 +2295,7 @@ static void migration_completion(MigrationState *s)
>               }
>               if (ret >= 0) {
>                   s->block_inactive = !migrate_colo();
> -                qemu_file_set_rate_limit(s->to_dst_file, 0);
> +                migration_rate_limit_set(0);
>                   ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
>                                                            s->block_inactive);
>               }
> @@ -2691,7 +2691,7 @@ static void migration_update_counters(MigrationState *s,
>               stat64_get(&mig_stats.dirty_bytes_last_sync) / bandwidth;
>       }
>   
> -    qemu_file_reset_rate_limit(s->to_dst_file);
> +    migration_rate_limit_reset();
>   
>       update_iteration_initial_status(s);
>   
> @@ -2847,7 +2847,7 @@ bool migration_rate_limit(void)
>   
>       bool urgent = false;
>       migration_update_counters(s, now);
> -    if (qemu_file_rate_limit(s->to_dst_file)) {
> +    if (migration_rate_limit_exceeded(s->to_dst_file)) {
>   
>           if (qemu_file_get_error(s->to_dst_file)) {
>               return false;
> @@ -2969,7 +2969,7 @@ static void *migration_thread(void *opaque)
>       trace_migration_thread_setup_complete();
>   
>       while (migration_is_active(s)) {
> -        if (urgent || !qemu_file_rate_limit(s->to_dst_file)) {
> +        if (urgent || !migration_rate_limit_exceeded(s->to_dst_file)) {
>               MigIterateState iter_state = migration_iteration_run(s);
>               if (iter_state == MIG_ITERATE_SKIP) {
>                   continue;
> @@ -3043,7 +3043,7 @@ static void *bg_migration_thread(void *opaque)
>       rcu_register_thread();
>       object_ref(OBJECT(s));
>   
> -    qemu_file_set_rate_limit(s->to_dst_file, 0);
> +    migration_rate_limit_set(0);
>   
>       setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
>       /*
> @@ -3215,7 +3215,7 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
>           notifier_list_notify(&migration_state_notifiers, s);
>       }
>   
> -    qemu_file_set_rate_limit(s->to_dst_file, rate_limit);
> +    migration_rate_limit_set(rate_limit);
>       qemu_file_set_blocking(s->to_dst_file, true);
>   
>       /*
> diff --git a/migration/multifd.c b/migration/multifd.c
> index 4e71c19292..2efb313be4 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -432,7 +432,7 @@ static int multifd_send_pages(QEMUFile *f)
>       multifd_send_state->pages = p->pages;
>       p->pages = pages;
>       transferred = ((uint64_t) pages->num) * p->page_size + p->packet_len;
> -    qemu_file_acct_rate_limit(f, transferred);
> +    migration_rate_limit_account(transferred);
>       qemu_mutex_unlock(&p->mutex);
>       stat64_add(&mig_stats.transferred, transferred);
>       stat64_add(&mig_stats.multifd_bytes, transferred);
> diff --git a/migration/options.c b/migration/options.c
> index d04b5fbc3a..a024fa3ce6 100644
> --- a/migration/options.c
> +++ b/migration/options.c
> @@ -23,6 +23,7 @@
>   #include "migration/colo.h"
>   #include "migration/misc.h"
>   #include "migration.h"
> +#include "migration-stats.h"
>   #include "qemu-file.h"
>   #include "ram.h"
>   #include "options.h"
> @@ -1242,8 +1243,7 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
>       if (params->has_max_bandwidth) {
>           s->parameters.max_bandwidth = params->max_bandwidth;
>           if (s->to_dst_file && !migration_in_postcopy()) {
> -            qemu_file_set_rate_limit(s->to_dst_file,
> -                                s->parameters.max_bandwidth);
> +            migration_rate_limit_set(s->parameters.max_bandwidth);
>           }
>       }
>   
> @@ -1274,8 +1274,7 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
>       if (params->has_max_postcopy_bandwidth) {
>           s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth;
>           if (s->to_dst_file && migration_in_postcopy()) {
> -            qemu_file_set_rate_limit(s->to_dst_file,
> -                    s->parameters.max_postcopy_bandwidth);
> +            migration_rate_limit_set(s->parameters.max_postcopy_bandwidth);
>           }
>       }
>       if (params->has_max_cpu_throttle) {
> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> index 8de1ecd082..3f993e24af 100644
> --- a/migration/qemu-file.c
> +++ b/migration/qemu-file.c
> @@ -27,6 +27,7 @@
>   #include "qemu/error-report.h"
>   #include "qemu/iov.h"
>   #include "migration.h"
> +#include "migration-stats.h"
>   #include "qemu-file.h"
>   #include "trace.h"
>   #include "options.h"
> @@ -40,17 +41,6 @@ struct QEMUFile {
>       QIOChannel *ioc;
>       bool is_writable;
>   
> -    /*
> -     * Maximum amount of data in bytes to transfer during one
> -     * rate limiting time window
> -     */
> -    uint64_t rate_limit_max;
> -    /*
> -     * Total amount of data in bytes queued for transfer
> -     * during this rate limiting time window
> -     */
> -    uint64_t rate_limit_used;
> -
>       /* The sum of bytes transferred on the wire */
>       uint64_t total_transferred;
>   
> @@ -302,7 +292,7 @@ void qemu_fflush(QEMUFile *f)
>               qemu_file_set_error_obj(f, -EIO, local_error);
>           } else {
>               uint64_t size = iov_size(f->iov, f->iovcnt);
> -            qemu_file_acct_rate_limit(f, size);
> +            migration_rate_limit_account(size);
>               f->total_transferred += size;
>           }
>   
> @@ -355,7 +345,7 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
>           int ret = f->hooks->save_page(f, block_offset,
>                                         offset, size, bytes_sent);
>           if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
> -            qemu_file_acct_rate_limit(f, size);
> +            migration_rate_limit_account(size);
>           }
>   
>           if (ret != RAM_SAVE_CONTROL_DELAYED &&
> @@ -726,43 +716,6 @@ uint64_t qemu_file_transferred(QEMUFile *f)
>       return f->total_transferred;
>   }
>   
> -int qemu_file_rate_limit(QEMUFile *f)
> -{
> -    if (qemu_file_get_error(f)) {
> -        return 1;
> -    }
> -    /*
> -     *  rate_limit_max == 0 means no rate_limit enfoncement.
> -     */
> -    if (f->rate_limit_max > 0 && f->rate_limit_used > f->rate_limit_max) {
> -        return 1;
> -    }
> -    return 0;
> -}
> -
> -uint64_t qemu_file_get_rate_limit(QEMUFile *f)
> -{
> -    return f->rate_limit_max;
> -}
> -
> -void qemu_file_set_rate_limit(QEMUFile *f, uint64_t limit)
> -{
> -    /*
> -     * 'limit' is per second.  But we check it each 100 miliseconds.
> -     */
> -    f->rate_limit_max = limit / XFER_LIMIT_RATIO;
> -}
> -
> -void qemu_file_reset_rate_limit(QEMUFile *f)
> -{
> -    f->rate_limit_used = 0;
> -}
> -
> -void qemu_file_acct_rate_limit(QEMUFile *f, uint64_t len)
> -{
> -    f->rate_limit_used += len;
> -}
> -
>   void qemu_put_be16(QEMUFile *f, unsigned int v)
>   {
>       qemu_put_byte(f, v >> 8);
> diff --git a/migration/qemu-file.h b/migration/qemu-file.h
> index ab164a58d0..46029b951c 100644
> --- a/migration/qemu-file.h
> +++ b/migration/qemu-file.h
> @@ -129,17 +129,6 @@ void qemu_file_skip(QEMUFile *f, int size);
>    * accounting information tracks the total migration traffic.
>    */
>   void qemu_file_credit_transfer(QEMUFile *f, size_t size);
> -void qemu_file_reset_rate_limit(QEMUFile *f);
> -/*
> - * qemu_file_acct_rate_limit:
> - *
> - * Report on a number of bytes the have been transferred
> - * out of band from the main file object I/O methods, and
> - * need to be applied to the rate limiting calcuations
> - */
> -void qemu_file_acct_rate_limit(QEMUFile *f, uint64_t len);
> -void qemu_file_set_rate_limit(QEMUFile *f, uint64_t new_rate);
> -uint64_t qemu_file_get_rate_limit(QEMUFile *f);
>   int qemu_file_get_error_obj(QEMUFile *f, Error **errp);
>   int qemu_file_get_error_obj_any(QEMUFile *f1, QEMUFile *f2, Error **errp);
>   void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
> diff --git a/migration/ram.c b/migration/ram.c
> index 5ae1fdba45..2339a99932 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -3351,7 +3351,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
>   
>           t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
>           i = 0;
> -        while ((ret = qemu_file_rate_limit(f)) == 0 ||
> +        while ((ret = migration_rate_limit_exceeded(f)) == 0 ||
            while (!(ret = migration_rate_limit_exceeded(f))) ||

Otherwise, looks fine.

regards,
Harsh
>                  postcopy_has_request(rs)) {
>               int pages;
>   
> diff --git a/migration/savevm.c b/migration/savevm.c
> index c7af9050c2..376118bc98 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1345,7 +1345,7 @@ int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
>               !(se->ops->has_postcopy && se->ops->has_postcopy(se->opaque))) {
>               continue;
>           }
> -        if (qemu_file_rate_limit(f)) {
> +        if (migration_rate_limit_exceeded(f)) {
>               return 0;
>           }
>           trace_savevm_section_start(se->idstr, se->section_id);

Harsh Prateek Bora <harshpb@linux.ibm.com> wrote:
> On 5/8/23 18:38, Juan Quintela wrote:
>> This way we can make them atomic and use this functions from any
>
> s/this/these
>

Fixed.

Thanks.

On 5/9/23 16:40, Juan Quintela wrote:
> Harsh Prateek Bora <harshpb@linux.ibm.com> wrote:
>> On 5/8/23 18:38, Juan Quintela wrote:
>>> This way we can make them atomic and use this functions from any
>>
>> s/this/these
>>
> 
> Fixed.
> 
Sure, providing ack from ppc/spapr perspective.

Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>

> Thanks.
> 
>