* [Qemu-devel] [PATCH] Split ram_save_block
@ 2014-05-09 10:54 Dr. David Alan Gilbert (git)
2014-05-12 10:36 ` Juan Quintela
0 siblings, 1 reply; 2+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2014-05-09 10:54 UTC (permalink / raw)
To: qemu-devel; +Cc: quintela
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
ram_save_block is getting a bit too complicated, and does two separate
things:
1) Finds a page to send
2) Sends the page (dealing with compression etc)
Split into 'ram_save_page' to send the page and deal with compression (2)
Rename remaining function to 'ram_find_and_save_block'
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
arch_init.c | 141 ++++++++++++++++++++++++++++++++++--------------------------
1 file changed, 79 insertions(+), 62 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index be743fd..e33d482 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -560,20 +560,93 @@ static void migration_bitmap_sync(void)
}
/*
- * ram_save_block: Writes a page of memory to the stream f
+ * ram_save_page: Send the given page to the stream
+ *
+ * Returns: Number of bytes written.
+ */
+static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
+ bool last_stage)
+{
+ int bytes_sent;
+ int cont;
+ ram_addr_t current_addr;
+ MemoryRegion *mr = block->mr;
+ uint8_t *p;
+ int ret;
+ bool send_async = true;
+
+ cont = (block == last_sent_block) ? RAM_SAVE_FLAG_CONTINUE : 0;
+
+ p = memory_region_get_ram_ptr(mr) + offset;
+
+ /* In doubt sent page as normal */
+ bytes_sent = -1;
+ ret = ram_control_save_page(f, block->offset,
+ offset, TARGET_PAGE_SIZE, &bytes_sent);
+
+ XBZRLE_cache_lock();
+
+ current_addr = block->offset + offset;
+ if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
+ if (ret != RAM_SAVE_CONTROL_DELAYED) {
+ if (bytes_sent > 0) {
+ acct_info.norm_pages++;
+ } else if (bytes_sent == 0) {
+ acct_info.dup_pages++;
+ }
+ }
+ } else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
+ acct_info.dup_pages++;
+ bytes_sent = save_block_hdr(f, block, offset, cont,
+ RAM_SAVE_FLAG_COMPRESS);
+ qemu_put_byte(f, 0);
+ bytes_sent++;
+ /* Must let xbzrle know, otherwise a previous (now 0'd) cached
+ * page would be stale
+ */
+ xbzrle_cache_zero_page(current_addr);
+ } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
+ bytes_sent = save_xbzrle_page(f, &p, current_addr, block,
+ offset, cont, last_stage);
+ if (!last_stage) {
+ /* Can't send this cached data async, since the cache page
+ * might get updated before it gets to the wire
+ */
+ send_async = false;
+ }
+ }
+
+ /* XBZRLE overflow or normal page */
+ if (bytes_sent == -1) {
+ bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
+ if (send_async) {
+ qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
+ } else {
+ qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
+ }
+ bytes_sent += TARGET_PAGE_SIZE;
+ acct_info.norm_pages++;
+ }
+
+ XBZRLE_cache_unlock();
+
+ return bytes_sent;
+}
+
+/*
+ * ram_find_and_save_block: Finds a page to send and sends it to f
*
* Returns: The number of bytes written.
* 0 means no dirty pages
*/
-static int ram_save_block(QEMUFile *f, bool last_stage)
+static int ram_find_and_save_block(QEMUFile *f, bool last_stage)
{
RAMBlock *block = last_seen_block;
ram_addr_t offset = last_offset;
bool complete_round = false;
int bytes_sent = 0;
MemoryRegion *mr;
- ram_addr_t current_addr;
if (!block)
block = QTAILQ_FIRST(&ram_list.blocks);
@@ -594,64 +667,8 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
ram_bulk_stage = false;
}
} else {
- int ret;
- uint8_t *p;
- bool send_async = true;
- int cont = (block == last_sent_block) ?
- RAM_SAVE_FLAG_CONTINUE : 0;
-
- p = memory_region_get_ram_ptr(mr) + offset;
-
- /* In doubt sent page as normal */
- bytes_sent = -1;
- ret = ram_control_save_page(f, block->offset,
- offset, TARGET_PAGE_SIZE, &bytes_sent);
-
- XBZRLE_cache_lock();
-
- current_addr = block->offset + offset;
- if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
- if (ret != RAM_SAVE_CONTROL_DELAYED) {
- if (bytes_sent > 0) {
- acct_info.norm_pages++;
- } else if (bytes_sent == 0) {
- acct_info.dup_pages++;
- }
- }
- } else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
- acct_info.dup_pages++;
- bytes_sent = save_block_hdr(f, block, offset, cont,
- RAM_SAVE_FLAG_COMPRESS);
- qemu_put_byte(f, 0);
- bytes_sent++;
- /* Must let xbzrle know, otherwise a previous (now 0'd) cached
- * page would be stale
- */
- xbzrle_cache_zero_page(current_addr);
- } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
- bytes_sent = save_xbzrle_page(f, &p, current_addr, block,
- offset, cont, last_stage);
- if (!last_stage) {
- /* Can't send this cached data async, since the cache page
- * might get updated before it gets to the wire
- */
- send_async = false;
- }
- }
+ bytes_sent = ram_save_page(f, block, offset, last_stage);
- /* XBZRLE overflow or normal page */
- if (bytes_sent == -1) {
- bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
- if (send_async) {
- qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
- } else {
- qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
- }
- bytes_sent += TARGET_PAGE_SIZE;
- acct_info.norm_pages++;
- }
-
- XBZRLE_cache_unlock();
/* if page is unmodified, continue to the next */
if (bytes_sent > 0) {
last_sent_block = block;
@@ -850,7 +867,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
while ((ret = qemu_file_rate_limit(f)) == 0) {
int bytes_sent;
- bytes_sent = ram_save_block(f, false);
+ bytes_sent = ram_find_and_save_block(f, false);
/* no more blocks to sent */
if (bytes_sent == 0) {
break;
@@ -912,7 +929,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
while (true) {
int bytes_sent;
- bytes_sent = ram_save_block(f, true);
+ bytes_sent = ram_find_and_save_block(f, true);
/* no more blocks to sent */
if (bytes_sent == 0) {
break;
--
1.9.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [Qemu-devel] [PATCH] Split ram_save_block
2014-05-09 10:54 [Qemu-devel] [PATCH] Split ram_save_block Dr. David Alan Gilbert (git)
@ 2014-05-12 10:36 ` Juan Quintela
0 siblings, 0 replies; 2+ messages in thread
From: Juan Quintela @ 2014-05-12 10:36 UTC (permalink / raw)
To: Dr. David Alan Gilbert (git); +Cc: qemu-devel
"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> ram_save_block is getting a bit too complicated, and does two separate
> things:
> 1) Finds a page to send
> 2) Sends the page (dealing with compression etc)
>
> Split into 'ram_save_page' to send the page and deal with compression (2)
> Rename remaining function to 'ram_find_and_save_block'
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
^ permalink raw reply [flat|nested] 2+ messages in thread
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