Date: Fri, 8 Jan 2010 15:46:26 -0600 (CST)
From: Christoph Lameter <cl@linux-foundation.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
cc: Peter Zijlstra <peterz@infradead.org>,
       KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
       Minchan Kim <minchan.kim@gmail.com>,
       "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "linux-mm@kvack.org" <linux-mm@kvack.org>,
       "hugh.dickins" <hugh.dickins@tiscali.co.uk>,
       Nick Piggin <nickpiggin@yahoo.com.au>, Ingo Molnar <mingo@elte.hu>
Subject: Re: [RFC][PATCH 6/8] mm: handle_speculative_fault()
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On Fri, 8 Jan 2010, Linus Torvalds wrote:

> We worried about the effects of fair spinlocks when introducing the ticket
> locks, but nobody ever actually had a load that seemed to indicate it made
> much of a difference, and we did have a few cases where starvation was a
> very noticeable problem.

And I made the point that starvation was a hardware issue due to immature
cacheline handling. Now the software patchup job for the hardware breakage
is causing regressions for everyone.


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