Date: Thu, 23 Oct 2014 13:04:38 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
        Ingo Molnar <mingo@kernel.org>, torvalds@linux-foundation.org,
        paulmck@linux.vnet.ibm.com, tglx@linutronix.de,
        akpm@linux-foundation.org, riel@redhat.com, mgorman@suse.de,
        oleg@redhat.com, mingo@redhat.com, minchan@kernel.org,
        kamezawa.hiroyu@jp.fujitsu.com, viro@zeniv.linux.org.uk,
        dave@stgolabs.net, linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC][PATCH 0/6] Another go at speculative page faults
Message-ID: <20141023110438.GQ21513@worktop.programming.kicks-ass.net>
References: <20141020215633.717315139@infradead.org>
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 <20141021170948.GA25964@node.dhcp.inet.fi>
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On Thu, Oct 23, 2014 at 06:40:05PM +0800, Lai Jiangshan wrote:
> On 10/22/2014 01:56 AM, Peter Zijlstra wrote:
> > On Tue, Oct 21, 2014 at 08:09:48PM +0300, Kirill A. Shutemov wrote:
> >> It would be interesting to see if the patchset affects non-condended case.
> >> Like a one-threaded workload.
> > 
> > It does, and not in a good way, I'll have to look at that... :/
> 
> Maybe it is blamed to find_vma_srcu() that it doesn't take the advantage of
> the vmacache_find() and cause more cache-misses.

Its what I thought initially, I tried doing perf record with and
without, but then I ran into perf diff not quite working for me and I've
yet to find time to kick that thing into shape.

> Is it hard to use the vmacache in the find_vma_srcu()?

I've not had time to look at it.
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