[Qemu-devel] [PATCH v3 1/2] arch_init: make is_zero_page accept size

[Qemu-devel] [PATCH v3 1/2] arch_init: make is_zero_page accept size

[Isaku Yamahata]

Later is_zero_page will be used for non TARGET_PAGE_SIZE
range.
And rename it to is_zero_range as it isn't page size any more.

Signed-off-by: Isaku Yamahata <yamahata@private.email.ne.jp>
---
 arch_init.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index e47e139..83b165b 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -150,10 +150,9 @@ int qemu_read_default_config_files(bool userconfig)
     return 0;
 }
 
-static inline bool is_zero_page(uint8_t *p)
+static inline bool is_zero_range(uint8_t *p, uint64_t size)
 {
-    return buffer_find_nonzero_offset(p, TARGET_PAGE_SIZE) ==
-        TARGET_PAGE_SIZE;
+    return buffer_find_nonzero_offset(p, size) == size;
 }
 
 /* struct contains XBZRLE cache and a static page
@@ -497,7 +496,7 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
                         acct_info.dup_pages++;
                     }
                 }
-            } else if (is_zero_page(p)) {
+            } 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);
@@ -844,7 +843,7 @@ static inline void *host_from_stream_offset(QEMUFile *f,
  */
 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
 {
-    if (ch != 0 || !is_zero_page(host)) {
+    if (ch != 0 || !is_zero_range(host, TARGET_PAGE_SIZE)) {
         memset(host, ch, size);
 #ifndef _WIN32
         if (ch == 0 &&
-- 
1.7.10.4

[Qemu-devel] [PATCH v3 2/2] migration: ram_handle_compressed

[Isaku Yamahata]

ram_handle_compressed() should be aware of size > TARGET_PAGE_SIZE.
migration-rdma can call it with larger size.

Signed-off-by: Isaku Yamahata <yamahata@private.email.ne.jp>
---
Changes v2 -> v3:
- use is_zero_range()

changes v1 -> v2:
- don't loop
---
 arch_init.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index 83b165b..1a444f5 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -843,13 +843,14 @@ static inline void *host_from_stream_offset(QEMUFile *f,
  */
 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
 {
-    if (ch != 0 || !is_zero_range(host, TARGET_PAGE_SIZE)) {
+    if (ch != 0 || !is_zero_range(host, size)) {
         memset(host, ch, 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);
+        if (ch == 0 && (!kvm_enabled() || kvm_has_sync_mmu())) {
+            size = size & ~(getpagesize() - 1);
+            if (size > 0) {
+                qemu_madvise(host, size, QEMU_MADV_DONTNEED);
+            }
         }
 #endif
     }
-- 
1.7.10.4

Re: [Qemu-devel] [PATCH v3 2/2] migration: ram_handle_compressed

[Juan Quintela]

Isaku Yamahata <yamahata@private.email.ne.jp> wrote:
> ram_handle_compressed() should be aware of size > TARGET_PAGE_SIZE.
> migration-rdma can call it with larger size.
>
> Signed-off-by: Isaku Yamahata <yamahata@private.email.ne.jp>

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

Re: [Qemu-devel] [PATCH v3 1/2] arch_init: make is_zero_page accept size

[Juan Quintela]

Isaku Yamahata <yamahata@private.email.ne.jp> wrote:
> Later is_zero_page will be used for non TARGET_PAGE_SIZE
> range.
> And rename it to is_zero_range as it isn't page size any more.
>
> Signed-off-by: Isaku Yamahata <yamahata@private.email.ne.jp>

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