From: Wei Yang <richardw.yang@linux.intel.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: pbonzini@redhat.com, quintela@redhat.com,
Wei Yang <richardw.yang@linux.intel.com>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 2/3] migration/ram.c: start of cpu_physical_memory_sync_dirty_bitmap is always 0
Date: Fri, 31 May 2019 08:54:03 +0800 [thread overview]
Message-ID: <20190531005403.GA14980@richard> (raw)
In-Reply-To: <20190514142108.GG2753@work-vm>
On Tue, May 14, 2019 at 03:21:08PM +0100, Dr. David Alan Gilbert wrote:
>* Wei Yang (richardw.yang@linux.intel.com) wrote:
>> Since start of cpu_physical_memory_sync_dirty_bitmap is always 0, we can
>> remove this parameter and simplify the calculation a bit.
>>
>> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
>
>So I think you're right it's currently unused; however, lets ask
>Paolo: Do we need to keep this parameter for flexiblity?
>
Hi Paolo
Do you like this one?
>Dave
>
>> ---
>> include/exec/ram_addr.h | 15 ++++++---------
>> migration/ram.c | 2 +-
>> 2 files changed, 7 insertions(+), 10 deletions(-)
>>
>> diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
>> index 9ecd911c3e..3dfb2d52fb 100644
>> --- a/include/exec/ram_addr.h
>> +++ b/include/exec/ram_addr.h
>> @@ -409,18 +409,16 @@ static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
>>
>> static inline
>> uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
>> - ram_addr_t start,
>> ram_addr_t length,
>> uint64_t *real_dirty_pages)
>> {
>> ram_addr_t addr;
>> - unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
>> + unsigned long word = BIT_WORD(rb->offset >> TARGET_PAGE_BITS);
>> uint64_t num_dirty = 0;
>> unsigned long *dest = rb->bmap;
>>
>> - /* start address and length is aligned at the start of a word? */
>> - if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
>> - (start + rb->offset) &&
>> + /* offset and length is aligned at the start of a word? */
>> + if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) == (rb->offset) &&
>> !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
>> int k;
>> int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
>> @@ -428,14 +426,13 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
>> unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
>> unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
>> DIRTY_MEMORY_BLOCK_SIZE);
>> - unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
>>
>> rcu_read_lock();
>>
>> src = atomic_rcu_read(
>> &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
>>
>> - for (k = page; k < page + nr; k++) {
>> + for (k = 0; k < nr; k++) {
>> if (src[idx][offset]) {
>> unsigned long bits = atomic_xchg(&src[idx][offset], 0);
>> unsigned long new_dirty;
>> @@ -458,11 +455,11 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
>>
>> for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
>> if (cpu_physical_memory_test_and_clear_dirty(
>> - start + addr + offset,
>> + addr + offset,
>> TARGET_PAGE_SIZE,
>> DIRTY_MEMORY_MIGRATION)) {
>> *real_dirty_pages += 1;
>> - long k = (start + addr) >> TARGET_PAGE_BITS;
>> + long k = addr >> TARGET_PAGE_BITS;
>> if (!test_and_set_bit(k, dest)) {
>> num_dirty++;
>> }
>> diff --git a/migration/ram.c b/migration/ram.c
>> index 9948b2d021..1def8122e9 100644
>> --- a/migration/ram.c
>> +++ b/migration/ram.c
>> @@ -1646,7 +1646,7 @@ static void migration_bitmap_sync_range(RAMState *rs, RAMBlock *rb,
>> ram_addr_t length)
>> {
>> rs->migration_dirty_pages +=
>> - cpu_physical_memory_sync_dirty_bitmap(rb, 0, length,
>> + cpu_physical_memory_sync_dirty_bitmap(rb, length,
>> &rs->num_dirty_pages_period);
>> }
>>
>> --
>> 2.19.1
>>
>--
>Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
--
Wei Yang
Help you, Help me
next prev parent reply other threads:[~2019-05-31 0:55 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-30 3:44 [Qemu-devel] [PATCH 0/3] Cleanup migration/ram.c Wei Yang
2019-04-30 3:44 ` Wei Yang
2019-04-30 3:44 ` [Qemu-devel] [PATCH 1/3] migration/ram.c: start of migration_bitmap_sync_range is always 0 Wei Yang
2019-04-30 3:44 ` Wei Yang
2019-05-14 14:15 ` Dr. David Alan Gilbert
2019-05-14 14:27 ` Dr. David Alan Gilbert
2019-05-15 6:41 ` Wei Yang
2019-05-15 8:04 ` Dr. David Alan Gilbert
2019-05-15 8:54 ` Wei Yang
2019-04-30 3:44 ` [Qemu-devel] [PATCH 2/3] migration/ram.c: start of cpu_physical_memory_sync_dirty_bitmap " Wei Yang
2019-04-30 3:44 ` Wei Yang
2019-05-14 14:21 ` Dr. David Alan Gilbert
2019-05-31 0:54 ` Wei Yang [this message]
2019-06-21 7:43 ` Wei Yang
2019-07-17 1:13 ` Wei Yang
2019-07-17 9:16 ` Paolo Bonzini
2019-07-18 1:07 ` Wei Yang
2019-04-30 3:44 ` [Qemu-devel] [PATCH 3/3] ram: RAMBlock->offset is always aligned to a word Wei Yang
2019-04-30 3:44 ` Wei Yang
2019-07-17 9:17 ` Paolo Bonzini
2019-07-18 1:11 ` Wei Yang
2019-05-01 22:53 ` [Qemu-devel] [PATCH 0/3] Cleanup migration/ram.c no-reply
2019-05-01 22:53 ` no-reply
2019-05-02 0:10 ` Wei Yang
2019-05-02 0:10 ` Wei Yang
2019-05-02 4:24 ` no-reply
2019-05-02 4:24 ` no-reply
2019-05-02 5:32 ` Wei Yang
2019-05-02 5:32 ` Wei Yang
2019-05-02 8:35 ` Dr. David Alan Gilbert
2019-05-02 8:35 ` Dr. David Alan Gilbert
2019-05-02 22:34 ` Wei Yang
2019-05-02 22:34 ` Wei Yang
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