[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 1/5] migration: Rework migrate_send_rp_req_pages() function
From: |
Peter Xu |
Subject: |
[PATCH 1/5] migration: Rework migrate_send_rp_req_pages() function |
Date: |
Thu, 3 Sep 2020 11:26:42 -0400 |
We duplicated the logic of maintaining the last_rb variable at both callers of
this function. Pass *rb pointer into the function so that we can avoid
duplicating the logic. Also, when we have the rb pointer, it's also easier to
remove the original 2nd & 4th parameters, because both of them (name of the
ramblock when needed, or the page size) can be fetched from the ramblock
pointer too.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
migration/migration.c | 26 ++++++++++++++++++--------
migration/migration.h | 4 ++--
migration/postcopy-ram.c | 24 ++----------------------
3 files changed, 22 insertions(+), 32 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index 58a5452471..6761e3f233 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -311,25 +311,35 @@ error:
return ret;
}
-/* Request a range of pages from the source VM at the given
- * start address.
- * rbname: Name of the RAMBlock to request the page in, if NULL it's the same
- * as the last request (a name must have been given previously)
+/* Request one page from the source VM at the given start address.
+ * rb: the RAMBlock to request the page in
* Start: Address offset within the RB
* Len: Length in bytes required - must be a multiple of pagesize
*/
-int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname,
- ram_addr_t start, size_t len)
+int migrate_send_rp_req_pages(MigrationIncomingState *mis, RAMBlock *rb,
+ ram_addr_t start)
{
uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname up to 256 */
size_t msglen = 12; /* start + len */
+ size_t len = qemu_ram_pagesize(rb);
enum mig_rp_message_type msg_type;
+ const char *rbname;
+ int rbname_len;
*(uint64_t *)bufc = cpu_to_be64((uint64_t)start);
*(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len);
- if (rbname) {
- int rbname_len = strlen(rbname);
+ /*
+ * We maintain the last ramblock that we requested for page. Note that we
+ * don't need locking because this function will only be called within the
+ * postcopy ram fault thread.
+ */
+ if (rb != mis->last_rb) {
+ mis->last_rb = rb;
+
+ rbname = qemu_ram_get_idstr(rb);
+ rbname_len = strlen(rbname);
+
assert(rbname_len < 256);
bufc[msglen++] = rbname_len;
diff --git a/migration/migration.h b/migration/migration.h
index ae497bd45a..ca8dc4c773 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -328,8 +328,8 @@ void migrate_send_rp_shut(MigrationIncomingState *mis,
uint32_t value);
void migrate_send_rp_pong(MigrationIncomingState *mis,
uint32_t value);
-int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
- ram_addr_t start, size_t len);
+int migrate_send_rp_req_pages(MigrationIncomingState *mis, RAMBlock *rb,
+ ram_addr_t start);
void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis,
char *block_name);
void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value);
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 1bb22f2b6c..11a70441a6 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -684,14 +684,7 @@ int postcopy_request_shared_page(struct PostCopyFD *pcfd,
RAMBlock *rb,
qemu_ram_get_idstr(rb), rb_offset);
return postcopy_wake_shared(pcfd, client_addr, rb);
}
- if (rb != mis->last_rb) {
- mis->last_rb = rb;
- migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
- aligned_rbo, pagesize);
- } else {
- /* Save some space */
- migrate_send_rp_req_pages(mis, NULL, aligned_rbo, pagesize);
- }
+ migrate_send_rp_req_pages(mis, rb, aligned_rbo);
return 0;
}
@@ -986,20 +979,7 @@ retry:
* Send the request to the source - we want to request one
* of our host page sizes (which is >= TPS)
*/
- if (rb != mis->last_rb) {
- mis->last_rb = rb;
- ret = migrate_send_rp_req_pages(mis,
- qemu_ram_get_idstr(rb),
- rb_offset,
- qemu_ram_pagesize(rb));
- } else {
- /* Save some space */
- ret = migrate_send_rp_req_pages(mis,
- NULL,
- rb_offset,
- qemu_ram_pagesize(rb));
- }
-
+ ret = migrate_send_rp_req_pages(mis, rb, rb_offset);
if (ret) {
/* May be network failure, try to wait for recovery */
if (ret == -EIO && postcopy_pause_fault_thread(mis)) {
--
2.26.2