lkml.org 
[lkml]   [2016]   [Dec]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC PATCH 0/3] Add a new flag for ITS device to control indirect route
From
Date
On 02/12/16 09:29, majun (Euler7) wrote:
>
>
> 在 2016/12/1 17:07, Marc Zyngier 写道:
>> On 01/12/16 07:45, Majun wrote:
>>> From: MaJun <majun258@huawei.com>
>>>
>>> For current ITS driver, two level table (indirect route) is enabled when the memory used
>>> for LPI route table over the limit(64KB * 2) size. But this function impact the
>>> performance of LPI interrupt actually because need more time to look up the table.
>>
>> Are you implying that your ITS doesn't have a cache to lookup the most
>> active devices, hence performing a full lookup on each interrupt?
>
> Our ITS chip has the cache with depth 64. But this seems not enough for some
> scenario,espeically on virtulization platform.

Then I don't see how switching to to flat tables is going to improve
things. Can you share actual performance numbers?

>> Anyway, doing this as a DT quirk doesn't feel right. Please use the ITS
>> quirk infrastructure.
>
> If there is no other better solutions, I will do this.

Thanks,

M.
--
Jazz is not dead. It just smells funny...

\
 
 \ /
  Last update: 2016-12-02 10:35    [W:0.081 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site