From: Andrew Morton <akpm@linux-foundation.org>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>,
Hugh Dickins <hughd@google.com>, Rik van Riel <riel@redhat.com>,
Michel Lespinasse <walken@google.com>,
Mel Gorman <mgorman@suse.de>,
Konstantin Khlebnikov <khlebnikov@openvz.org>,
Michal Hocko <mhocko@suse.cz>,
"AneeshKumarK.V" <aneesh.kumar@linux.vnet.ibm.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Hillf Danton <dhillf@gmail.com>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm/hugetlb: per-vma instantiation mutexes
Date: Mon, 15 Jul 2013 16:08:02 -0700 [thread overview]
Message-ID: <20130715160802.9d0cdc0ee012b5e119317a98@linux-foundation.org> (raw)
In-Reply-To: <20130715072432.GA28053@voom.fritz.box>
On Mon, 15 Jul 2013 17:24:32 +1000 David Gibson <david@gibson.dropbear.id.au> wrote:
> I have previously proposed a correct method of improving scalability,
> although it doesn't eliminate the lock. That's to use a set of hashed
> mutexes.
Yep - hashing the mutexes is an obvious and nicely localized way of
improving this. It's a tweak, not a design change.
The changelog should describe the choice of the hash key with great
precision, please. It's important and is the first thing which
reviewers and readers will zoom in on.
Should the individual mutexes be cacheline aligned? Depends on the
acquisition frequency, I guess. Please let's work through that.
Let's not damage uniprocesor kernels too much. AFACIT the main offender
here is fault_mutex_hash(), which is the world's most obfuscated "return
0;".
> It wasn't merged before, but I don't recall the reasons
> why.
Me either.
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next prev parent reply other threads:[~2013-07-15 23:08 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-12 23:28 Davidlohr Bueso
2013-07-13 0:54 ` Hugh Dickins
2013-07-15 3:16 ` Davidlohr Bueso
2013-07-15 7:24 ` David Gibson
2013-07-15 23:08 ` Andrew Morton [this message]
2013-07-16 0:12 ` Davidlohr Bueso
2013-07-16 8:00 ` David Gibson
2013-07-17 19:50 ` [PATCH] hugepage: allow parallelization of the hugepage fault path Davidlohr Bueso
2013-07-18 8:42 ` Joonsoo Kim
2013-07-19 7:14 ` David Gibson
2013-07-19 21:24 ` Davidlohr Bueso
2013-07-22 0:59 ` Joonsoo Kim
2013-07-18 9:07 ` Joonsoo Kim
2013-07-19 0:19 ` Davidlohr Bueso
2013-07-19 0:35 ` Davidlohr Bueso
2013-07-23 7:04 ` Hush Bensen
2013-07-23 6:55 ` Hush Bensen
2013-07-16 1:51 ` [PATCH] mm/hugetlb: per-vma instantiation mutexes Rik van Riel
2013-07-16 5:34 ` Joonsoo Kim
2013-07-16 10:01 ` David Gibson
2013-07-18 6:50 ` Joonsoo Kim
2013-07-16 8:20 ` David Gibson
2013-07-15 4:18 ` Konstantin Khlebnikov
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