Re: [Qemu-devel] [PATCH V2] add migration capability to bypass the shared memory

[Li, Liang Z]

> On Wed, Aug 10, 2016 at 10:22 AM, Li, Liang Z <address@hidden> wrote:
> > Hi Jiangshan,
> >
> > Glad to see your patch. It's a simple implementation which could provide
> very useful functions.
> >
> >> +static void migration_bitmap_init(unsigned long *bitmap) {
> >> +    RAMBlock *block;
> >> +
> >> +    bitmap_clear(bitmap, 0, last_ram_offset() >> TARGET_PAGE_BITS);
> >> +    rcu_read_lock();
> >> +    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> >> +        if (!migrate_bypass_shared_memory()
> >> || !qemu_ram_is_shared(block)) {
> >> +            bitmap_set(bitmap, block->offset >> TARGET_PAGE_BITS,
> >
> > You should use (block->offset >> TARGET_PAGE_BITS )/ BITS_PER_LONG
> here.
> 
> Hello, Li
> 
> I might have missed something, could you tell me more?
> 
> void bitmap_set(unsigned long *map, long start, long nr); I think the @start
> and @nr are both the number of the bits.
> 
> thanks,
> Lai

You are right,  I have make a mistake by checking the code. Sorry for the noise.

BTW. Is it possible to bypass the shared block in the 'ram_find_and_save_block'?
I mean no to check if a page is dirty for a shared block, it may make things 
faster.

Liang