linux-kernel - RE: [PATCH v2] x86: Quark: Add if/else to setup

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Date:	Tue, 30 Sep 2014 01:46:04 +0000
From:	"Ong, Boon Leong" <boon.leong.ong@...el.com>
To:	"'pure.logic@...us-software.ie'" <pure.logic@...us-software.ie>,
	Henrique de Moraes Holschuh <hmh@....eng.br>
CC:	"hpa@...or.com" <hpa@...or.com>,
	"mingo@...hat.com" <mingo@...hat.com>,
	"tglx@...utronix.de" <tglx@...utronix.de>,
	"davej@...hat.com" <davej@...hat.com>,
	"x86@...nel.org" <x86@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v2] x86: Quark: Add if/else to setup_arch for Quark TLB
 bug

> 
> My view is that the CR3 load should have flushed the TLB in it's entirety.
> 
> Ong Boong Leong said that a discussion he had which included HPA concluded
> with a flush of the TLB being required after the CR3 reload.

The proposed patch was discussed in April and after much thought into this,
I will suggest that as long as the commentary properly captured down why
__flush_tlb() is **NOT** needed because load_cr3() will have the same effect.

> 
> The current code
> 
> My preference is
> 
> 1. Just comment the code as is to explain why it works for Quark.
> 
> If that's not good enough for people then
> 
> 2. if/else the flow so that Quark does __flush_tlb() and the rest of the world
> does a __flush_tlb_all()
Bryan, just drop this proposal from my submission even though __flush_tlb() is
more obvious in what is supposed to do and does not consume any significant cpu-time.


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