From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Balbir Singh <bsingharora@gmail.com>,
benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc/mm: Use tlbiel only if we ever ran on the current cpu
Date: Mon, 24 Oct 2016 11:31:33 +0530 [thread overview]
Message-ID: <87funmb802.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <9b21edc6-061b-ad66-1bbc-07c7d0048e6c@gmail.com>
Balbir Singh <bsingharora@gmail.com> writes:
> On 24/10/16 14:20, Aneesh Kumar K.V wrote:
>> Before this patch, we used tlbiel, if we ever ran only on this core.
>> That was mostly derived from the nohash usage of the same. But the
>> ISA 3.0 clarifies tlbiel such that
>>
>> "All TLB entries that have all of the following properties are made
>> invalid on the thread executing the tlbiel instruction"
>>
>> Hence use tlbiel, if we only ever ran on just the current cpu.
>>
>
> Could you clarify the impact. The impact I see is that it could
> lead to us thinking we invalidated the TLB across the core whereas
> we did it only on the current thread? This could leave others threads
> in the same core with invalid TLB's, if cpumask reported we ran on
> other threads in the same core?
Correct.
-aneesh
next prev parent reply other threads:[~2016-10-24 6:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-24 3:20 [PATCH] powerpc/mm: Use tlbiel only if we ever ran on the current cpu Aneesh Kumar K.V
2016-10-24 3:40 ` Balbir Singh
2016-10-24 6:01 ` Aneesh Kumar K.V [this message]
2016-10-27 11:38 ` Michael Ellerman
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