Re: [Qemu-devel] [RFC PATCH COLO v2 10/13] Backup: clear all bitmap when doing block checkpoint

[Wen Congyang]

On 03/25/2015 08:55 PM, Paolo Bonzini wrote:
> 
> 
> On 25/03/2015 10:36, Wen Congyang wrote:
>>
>> +void backup_do_checkpoint(BlockJob *job, Error **errp)
>> +{
>> +    BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
>> +
>> +    if (job->driver != &backup_job_driver) {
>> +        error_setg(errp, "It is not backup job");
>> +        return;
>> +    }
>> +
>> +    hbitmap_reset_all(backup_job->bitmap);
>> +}
> 
> Please add instead a block_job_do_checkpoint API, and a do_checkpoint
> function pointer to BlockJobDriver.
> 
>> +{
>> +#if 0
>> +    hbitmap_reset(hb, 0, hb->size << hb->granularity);
>> +#else
>> +    uint64_t size = hb->size;
>> +    unsigned int i;
>> +
>> +    /* Same as hbitmap_alloc() except memset() */
>> +    for (i = HBITMAP_LEVELS; i-- > 0; ) {
> 
> This can be "--i >= 1"...
> 
>> +        size = MAX((size + BITS_PER_LONG - 1) >> BITS_PER_LEVEL, 1);
>> +        memset(hb->levels[i], 0, size * sizeof(unsigned long));
>> +    }
>> +
>> +    assert(size == 1);
>> +    hb->levels[0][0] |= 1UL << (BITS_PER_LONG - 1);
> 
> ... if you use "=" instead of "|=" here.
> 
>> +#endif
>> +}
> 
> Please pick one implementation (no #if), and also add a testcase to
> tests/test-hbitmap.c.

OK

Thanks
Wen Congyang

> 
> Paolo
> .
>