Messages in this thread | | | Subject | Re: [RFC PATCH 0/3] Add a new flag for ITS device to control indirect route | From | Marc Zyngier <> | Date | Fri, 2 Dec 2016 09:35:10 +0000 |
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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...
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