Re: [PATCH 4/4] drivers/xen/xenbus/xenbus_client.c: Improve the failure processing for __xenbus_switch_state()

Chen Gang
2014-09-15T22:57:24Z

On 09/15/2014 10:39 PM, David Vrabel wrote:
> On 14/09/14 11:52, Chen Gang wrote:
>> When failure occurs, need return failure code instead of 0, or the upper
>> caller will misunderstand.
>>
>> Also when retry for EAGAIN reason, better to schedule out for a while,
>> so can let others have chance to continue their tasks (especially,
>> their tasks are related EAGAIN under UP kernel).
>
> Is this fixing a real world problem you have seen?
>

Not real world, only reading by source code, and some of upper level
callers really check the return value, indirectly (they may
misunderstand).

> xenbus_scanf() and xenbus_printf() already sleep while waiting for the
> response and delaying isn't going to reduce the likelihood of the
> transaction being aborted on the retry.
>

OK, thanks, what you said sound reasonable to me, I shall remove the
waiting code when send patch v2 for it.

I shall try to send patch v2 within this week end (2014-09-21), if it is
too late to bare, please let me know (I shall try in time).

Thanks.
--
Chen Gang

Open share and attitude like air water and life which God blessed