linux-kernel - Re: [PATCH v7 8/8] x86/tlb: just do tlb flush on one of siblings of SMT

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Date:	Wed, 23 May 2012 19:15:38 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Jan Beulich <JBeulich@...e.com>
Cc:	Alex Shi <alex.shi@...el.com>, borislav.petkov@....com,
	arnd@...db.de, akinobu.mita@...il.com, eric.dumazet@...il.com,
	fweisbec@...il.com, rostedt@...dmis.org, hughd@...gle.com,
	jeremy@...p.org, len.brown@...el.com, tony.luck@...el.com,
	yongjie.ren@...el.com, kamezawa.hiroyu@...fujitsu.com,
	seto.hidetoshi@...fujitsu.com, penberg@...nel.org,
	yinghai@...nel.org, tglx@...utronix.de, akpm@...ux-foundation.org,
	ak@...ux.intel.com, luto@....edu, avi@...hat.com,
	dhowells@...hat.com, mingo@...hat.com, riel@...hat.com,
	cpw@....com, steiner@....com, linux-kernel@...r.kernel.org,
	viro@...iv.linux.org.uk, hpa@...or.com
Subject: Re: [PATCH v7 8/8] x86/tlb: just do tlb flush on one of siblings
 of SMT

On Wed, 2012-05-23 at 19:09 +0200, Peter Zijlstra wrote:
> > There is no comment or anything else indicating that this is
> > suitable for dual-thread CPUs only - when there are more than
> > 2 threads per core, the intended effect won't be achieved.
> 
> Why would that be? Won't higher thread count still share the same
> resources just more so? 

Ah, I see, you're saying his code is buggy for >2 threads. Agreed.

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