[dm-devel] dm-log-userspace: Allow mark requests to piggyback on flush requests

[Brassow Jonathan]

On Jan 13, 2014, at 8:59 PM, Mike Snitzer wrote:

> On Mon, Jan 13 2014 at  9:30pm -0500,
> Jonathan Brassow <jbrassow at redhat.com> wrote:
> 
>> dm-log-userspace: Allow mark requests to piggyback on flush requests
>> 
>> In the cluster evironment, cluster write has poor performance.
>> Because userspace_flush has to contact userspace program(cmirrord)
>> in clear/mark/flush request. But both mark and flush requests
>> require cmirrord to circle message to all the cluster nodes in each
>> flush call.  This behave is realy slow. So the idea is merging
>> mark and flush request together to reduce the kernel-userspace-kernel
>> time.  Allow a new directive, "integrated_flush" that can be used to
>> instruct the kernel log code to combine flush and mark requests when
>> directed by userspace.  Additionlly, flush requests are performed
>> lazily when only clear requests exist.
>> 
>> Signed-off-by: dongmao zhang <dmzhang at suse.com>
>> Signed-off-by: Jonathan Brassow <jbrassow at redhat.com>
> 
> Hey Jon,
> 
> Thanks for following through with this.  Should it be attributed to
> dongmao as the author?

Yes. Thanks.

 brassow