Migration Pull request

Hi
 
 This pull request includes:
 - fix sample-pages doc by hyman
 - cleanup colo pages by contiguous blocks by Rao
 - reset auto-converge by checkpoint by Rao.
 
 Please, apply.
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Merge remote-tracking branch 'remotes/juanquintela/tags/migration-20211109-pull-request' into staging

Migration Pull request

Hi

This pull request includes:
- fix sample-pages doc by hyman
- cleanup colo pages by contiguous blocks by Rao
- reset auto-converge by checkpoint by Rao.

Please, apply.

# gpg: Signature made Tue 09 Nov 2021 09:02:37 AM CET
# gpg:                using RSA key 1899FF8EDEBF58CCEE034B82F487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>" [full]
# gpg:                 aka "Juan Quintela <quintela@trasno.org>" [full]

* remotes/juanquintela/tags/migration-20211109-pull-request:
  Reset the auto-converge counter at every checkpoint.
  Reduce the PVM stop time during Checkpoint
  docs: fix 'sample-pages' option tag

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

migration/colo.c

@@ -459,6 +459,10 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     if (ret < 0) {
         goto out;
     }
+
+    if (migrate_auto_converge()) {
+        mig_throttle_counter_reset();
+    }
     /*
      * Only save VM's live state, which not including device state.
      * TODO: We may need a timeout mechanism to prevent COLO process

migration/ram.c

@@ -641,6 +641,15 @@ static void mig_throttle_guest_down(uint64_t bytes_dirty_period,
     }
 }
 
+void mig_throttle_counter_reset(void)
+{
+    RAMState *rs = ram_state;
+
+    rs->time_last_bitmap_sync = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+    rs->num_dirty_pages_period = 0;
+    rs->bytes_xfer_prev = ram_counters.transferred;
+}
+
 /**
  * xbzrle_cache_zero_page: insert a zero page in the XBZRLE cache
  *
@@ -836,6 +845,41 @@ migration_clear_memory_region_dirty_bitmap_range(RAMBlock *rb,
     }
 }
 
+/*
+ * colo_bitmap_find_diry:find contiguous dirty pages from start
+ *
+ * Returns the page offset within memory region of the start of the contiguout
+ * dirty page
+ *
+ * @rs: current RAM state
+ * @rb: RAMBlock where to search for dirty pages
+ * @start: page where we start the search
+ * @num: the number of contiguous dirty pages
+ */
+static inline
+unsigned long colo_bitmap_find_dirty(RAMState *rs, RAMBlock *rb,
+                                     unsigned long start, unsigned long *num)
+{
+    unsigned long size = rb->used_length >> TARGET_PAGE_BITS;
+    unsigned long *bitmap = rb->bmap;
+    unsigned long first, next;
+
+    *num = 0;
+
+    if (ramblock_is_ignored(rb)) {
+        return size;
+    }
+
+    first = find_next_bit(bitmap, size, start);
+    if (first >= size) {
+        return first;
+    }
+    next = find_next_zero_bit(bitmap, size, first + 1);
+    assert(next >= first);
+    *num = next - first;
+    return first;
+}
+
 static inline bool migration_bitmap_clear_dirty(RAMState *rs,
                                                 RAMBlock *rb,
                                                 unsigned long page)
@@ -3886,19 +3930,26 @@ void colo_flush_ram_cache(void)
         block = QLIST_FIRST_RCU(&ram_list.blocks);
 
         while (block) {
-            offset = migration_bitmap_find_dirty(ram_state, block, offset);
+            unsigned long num = 0;
 
+            offset = colo_bitmap_find_dirty(ram_state, block, offset, &num);
             if (!offset_in_ramblock(block,
                                     ((ram_addr_t)offset) << TARGET_PAGE_BITS)) {
                 offset = 0;
+                num = 0;
                 block = QLIST_NEXT_RCU(block, next);
             } else {
-                migration_bitmap_clear_dirty(ram_state, block, offset);
+                unsigned long i = 0;
+
+                for (i = 0; i < num; i++) {
+                    migration_bitmap_clear_dirty(ram_state, block, offset + i);
+                }
                 dst_host = block->host
                          + (((ram_addr_t)offset) << TARGET_PAGE_BITS);
                 src_host = block->colo_cache
                          + (((ram_addr_t)offset) << TARGET_PAGE_BITS);
-                memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+                memcpy(dst_host, src_host, TARGET_PAGE_SIZE * num);
+                offset += num;
             }
         }
     }

migration/ram.h

@@ -50,6 +50,7 @@ bool ramblock_is_ignored(RAMBlock *block);
 int xbzrle_cache_resize(uint64_t new_size, Error **errp);
 uint64_t ram_bytes_remaining(void);
 uint64_t ram_bytes_total(void);
+void mig_throttle_counter_reset(void);
 
 uint64_t ram_pagesize_summary(void);
 int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len);

qapi/migration.json

@@ -1796,7 +1796,7 @@
 # @calc-time: time in units of second for sample dirty pages
 #
 # @sample-pages: page count per GB for sample dirty pages
-#                the default value is 512 (since 6.2)
+#                the default value is 512 (since 6.1)
 #
 # @mode: mode containing method of calculate dirtyrate includes
 #        'page-sampling' and 'dirty-ring' (Since 6.2)