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Date:   Mon, 9 Mar 2020 08:33:25 -0700
From:   Andi Kleen <ak@linux.intel.com>
To:     "Kirill A. Shutemov" <kirill@shutemov.name>
Cc:     Cannon Matthews <cannonmatthews@google.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Matthew Wilcox <willy@infradead.org>,
        Michal Hocko <mhocko@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Greg Thelen <gthelen@google.com>,
        Salman Qazi <sqazi@google.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [PATCH] mm: clear 1G pages with streaming stores on x86
Message-ID: <20200309153325.GJ1454533@tassilo.jf.intel.com>
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> > Tested:
> > 	Time to `mlock()` a 512GiB region on broadwell CPU
> > 				AVG time (s)	% imp.	ms/page
> > 	clear_page_erms		133.584		-	261
> > 	clear_page_nt		34.154		74.43%	67
> 
> Some macrobenchmark would be great too.

Yes especially something that actually uses the memory. I suspect you'll need
something like the below

> That patchset is somewhat more complex trying to keep the memory around
> the fault address hot in cache. In theory it should help to reduce latency
> on the first access to the memory.

-Andi