* [Qemu-devel] [PATCH v2] migration: ram_handle_compressed
@ 2013-09-20 7:51 Isaku Yamahata
2013-09-20 14:09 ` Michael R. Hines
0 siblings, 1 reply; 2+ messages in thread
From: Isaku Yamahata @ 2013-09-20 7:51 UTC (permalink / raw)
To: qemu-devel; +Cc: owasserm, pbonzini, mrhines, quintela
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 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 e47e139..ab466fc 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -844,13 +844,14 @@ 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_page(host)) {
+ if (ch != 0 || buffer_find_nonzero_offset(host, size) != 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
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [Qemu-devel] [PATCH v2] migration: ram_handle_compressed
2013-09-20 7:51 [Qemu-devel] [PATCH v2] migration: ram_handle_compressed Isaku Yamahata
@ 2013-09-20 14:09 ` Michael R. Hines
0 siblings, 0 replies; 2+ messages in thread
From: Michael R. Hines @ 2013-09-20 14:09 UTC (permalink / raw)
To: Isaku Yamahata; +Cc: owasserm, quintela, mrhines, qemu-devel, pbonzini
On 09/20/2013 03:51 AM, Isaku Yamahata 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>
> ---
> 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 e47e139..ab466fc 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -844,13 +844,14 @@ 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_page(host)) {
> + if (ch != 0 || buffer_find_nonzero_offset(host, size) != 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
> }
NACK.
Why don't you modify the is_zero_page function *itself*?
This seems like an overly complicated solution - just modify the
is_zero_page function to pass along the size parameter and let
buffer_find_nonzero_offset() run the same code.
Fix the original problem - don't breakup the memory into smaller
pieces.....
- Michael
^ permalink raw reply [flat|nested] 2+ messages in thread
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2013-09-20 7:51 [Qemu-devel] [PATCH v2] migration: ram_handle_compressed Isaku Yamahata
2013-09-20 14:09 ` Michael R. Hines
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