Re: [PATCH v2 01/15] xen/arm: register mmio handler at runtime

From: Julien Grall <julien.grall@linaro.org>
To: Vijay Kilari <vijay.kilari@gmail.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Prasun Kapoor <Prasun.Kapoor@caviumnetworks.com>,
	Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>,
	Andrii Anisov <andrii.anisov@globallogic.com>,
	xen-devel@lists.xen.org,
	Stefano Stabellini <stefano.stabellini@citrix.com>
Subject: Re: [PATCH v2 01/15] xen/arm: register mmio handler at runtime
Date: Tue, 08 Apr 2014 11:51:46 +0100	[thread overview]
Message-ID: <5343D4C2.9050603@linaro.org> (raw)
In-Reply-To: <CALicx6tuwO3BKXdH6qNwCg-PLFkRXz9NRj+pWUxBnh5q+PzYVg@mail.gmail.com>

On 04/08/2014 11:34 AM, Vijay Kilari wrote:
>>>>>
>>>>>>
>>>>>> [..]
>>>>>>
>>>>>>> diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
>>>>>>> index 50b9b54..23dac85 100644
>>>>>>> --- a/xen/include/asm-arm/domain.h
>>>>>>> +++ b/xen/include/asm-arm/domain.h
>>>>>>> @@ -116,6 +116,7 @@ struct arch_domain
>>>>>>>      struct hvm_domain hvm_domain;
>>>>>>>      xen_pfn_t *grant_table_gpfn;
>>>>>>>
>>>>>>> +    struct io_handler *io_handlers;
>>>>>>
>>>>>> Why do you need a pointer here? I think can can directly use
>>>>>> struct io_handler iohandlers.
>>>>>>
>>>>>   I just adds to increase the size of this arch_domain struct.
>>>>> so allocated memory at runtime.
>>>>
>>>> Do you hit the page size?
>>> Yes, I have faced page size exhausted issue which I have reported earlier
>>
>> Did you still have the issue when you moved out GICv stuff outside?
> Now I am not getting this issue. But I feel we are on the edge. So it
> is always better
> to allocate runtime.

Hmmmm... we are not on the edge with the current Xen:
   - arm32: sizeof(struct domain) = 1024
   - arm64: sizeof(struct domain) = 1408

Unless if you have added lots of fields in the structure, there is no
reason to use a pointer here.

Regards,

-- 
Julien Grall