Patchwork [v5,07/12] rdma: introduce ram_handle_compressed()

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Submitter mrhines@linux.vnet.ibm.com
Date April 21, 2013, 9:17 p.m.
Message ID <1366579081-6857-8-git-send-email-mrhines@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/238265/
State New
Headers show

Comments

mrhines@linux.vnet.ibm.com - April 21, 2013, 9:17 p.m.
From: "Michael R. Hines" <mrhines@us.ibm.com>

This gives RDMA shared access to madvise() on the destination side
when an entire chunk is found to be zero.

Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
---
 arch_init.c                   |   24 ++++++++++++++++--------
 include/migration/migration.h |    2 ++
 2 files changed, 18 insertions(+), 8 deletions(-)

Patch

diff --git a/arch_init.c b/arch_init.c
index 92de1bd..e272852 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -770,6 +770,21 @@  static inline void *host_from_stream_offset(QEMUFile *f,
     return NULL;
 }
 
+/*
+ * If a page (or a whole RDMA chunk) has been
+ * determined to be zero, then zap it.
+ */
+void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
+{
+    memset(host, ch, TARGET_PAGE_SIZE);
+#ifndef _WIN32
+    if (ch == 0 && (!kvm_enabled() || kvm_has_sync_mmu()) &&
+                            getpagesize() <= TARGET_PAGE_SIZE) {
+        qemu_madvise(host, size, QEMU_MADV_DONTNEED);
+    }
+#endif
+}
+
 static int ram_load(QEMUFile *f, void *opaque, int version_id)
 {
     ram_addr_t addr;
@@ -837,14 +852,7 @@  static int ram_load(QEMUFile *f, void *opaque, int version_id)
             }
 
             ch = qemu_get_byte(f);
-            memset(host, ch, TARGET_PAGE_SIZE);
-#ifndef _WIN32
-            if (ch == 0 &&
-                (!kvm_enabled() || kvm_has_sync_mmu()) &&
-                getpagesize() <= TARGET_PAGE_SIZE) {
-                qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED);
-            }
-#endif
+            ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
         } else if (flags & RAM_SAVE_FLAG_PAGE) {
             void *host;
 
diff --git a/include/migration/migration.h b/include/migration/migration.h
index e2acec6..afc8641 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -105,6 +105,8 @@  uint64_t xbzrle_mig_pages_transferred(void);
 uint64_t xbzrle_mig_pages_overflow(void);
 uint64_t xbzrle_mig_pages_cache_miss(void);
 
+void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
+
 /**
  * @migrate_add_blocker - prevent migration from proceeding
  *