Re: [Qemu-devel] [PATCH v4 1/4] seqlock: introduce read-write seqlock

[Paolo Bonzini <pbonzini@redhat.com>]

Il 24/09/2013 07:33, liu ping fan ha scritto:
> On Mon, Sep 23, 2013 at 2:21 PM, Jan Kiszka <jan.kiszka@siemens.com> wrote:
>> On 2013-09-22 10:11, Liu Ping Fan wrote:
>>> This lets the read-side access run outside the BQL.
>>
>> In fact, not only BQL. Didn't the original commit provide a changlog
>> about the content of this patch? Otherwise, briefly describe use cases
>> and maybe the typical invocation pattern.
>>
> Original commit provide no changelog (right? Paolo, if I do miss the
> latest one in your tree).

Indeed I had never written one.

> What about the commit log like:
> 
> Seqlock implementation for QEMU. Usage idiom
> reader:
> seqlock_read_begin()
> do{
> }while(seqlock_read_try())
> 
> writer:
> seqlock_write_lock()
> ...
> seqlock_write_unlock()
> 
> initialization:
> seqlock_init(QemuSeqLock *sl, QemuMutex *mutex)
> where mutex could be NULL if the caller has provided extra lock
> protection for seqlock_write_lock.

replace "has provided" with "will provide".  Otherwise looks good.

Paolo