From: Hugh Dickins <hugh@veritas.com>
To: "Martin J. Bligh" <mbligh@aracnet.com>
Cc: Andrew Morton <akpm@osdl.org>, Andi Kleen <ak@suse.de>,
<colpatch@us.ibm.com>, <linux-kernel@vger.kernel.org>
Subject: Re: NUMA API for Linux
Date: Thu, 8 Apr 2004 19:16:12 +0100 (BST) [thread overview]
Message-ID: <Pine.LNX.4.44.0404081905510.7487-100000@localhost.localdomain> (raw)
In-Reply-To: <5470000.1081443942@flay>
On Thu, 8 Apr 2004, Martin J. Bligh wrote:
> > On Wed, 7 Apr 2004, Andrew Morton wrote:
> >>
> >> Your patch takes the CONFIG_NUMA vma from 64 bytes to 68. It would be nice
> >> to pull those 4 bytes back somehow.
> >
> > How significant is this vma size issue?
> >
> > anon_vma objrmap will add 20 bytes to each vma (on 32-bit arches):
> > 8 for prio_tree, 12 for anon_vma linkage in vma,
> > sometimes another 12 for the anon_vma head itself.
>
> Ewwww. Isn't some of that shared most of the time though?
The anon_vma head may well be shared with other vmas of the fork group.
But the anon_vma linkage is a list_head and a pointer within the vma.
prio_tree is already using a union as much as it can (and a pointer
where a list_head would simplify the code); Rajesh was thinking of
reusing vm_private_data for one pointer, but I've gone and used it
for nonlinear swapout.
> > anonmm objrmap adds just the 8 bytes for prio_tree,
> > remaining overhead 28 bytes per mm.
>
> 28 bytes per *mm* is nothing, and I still think the prio_tree is
> completely unneccesary. Nobody has ever demonstrated a real benchmark
> that needs it, as far as I recall.
I'm sure an Ingobench will shortly follow that observation.
Hugh
next prev parent reply other threads:[~2004-04-08 18:16 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-07 21:24 NUMA API for Linux Matthew Dobson
2004-04-07 21:27 ` Andi Kleen
2004-04-07 21:41 ` Matthew Dobson
2004-04-07 21:45 ` Andi Kleen
2004-04-07 22:19 ` Matthew Dobson
2004-04-08 0:58 ` Matthew Dobson
2004-04-08 1:31 ` Andi Kleen
2004-04-08 18:36 ` Matthew Dobson
2004-04-09 1:09 ` Matthew Dobson
2004-04-09 5:29 ` Martin J. Bligh
2004-04-09 18:44 ` Matthew Dobson
2004-04-15 0:38 ` Matthew Dobson
2004-04-15 10:39 ` Andi Kleen
2004-04-15 11:48 ` Robin Holt
2004-04-15 18:32 ` Matthew Dobson
2004-04-15 19:44 ` Matthew Dobson
2004-04-07 21:35 ` Matthew Dobson
2004-04-07 21:51 ` Andrew Morton
2004-04-07 22:16 ` Andi Kleen
2004-04-07 22:34 ` Andrew Morton
2004-04-07 22:39 ` Martin J. Bligh
2004-04-07 22:33 ` Andi Kleen
2004-04-07 22:38 ` Martin J. Bligh
2004-04-07 22:38 ` Andi Kleen
2004-04-07 22:52 ` Andrew Morton
2004-04-07 23:09 ` Martin J. Bligh
2004-04-07 23:35 ` Andi Kleen
2004-04-07 23:56 ` Andrew Morton
2004-04-08 0:14 ` Andi Kleen
2004-04-08 0:26 ` Andrea Arcangeli
2004-04-08 0:51 ` Andi Kleen
2004-04-08 16:15 ` Hugh Dickins
2004-04-08 17:05 ` Martin J. Bligh
2004-04-08 18:16 ` Hugh Dickins [this message]
2004-04-08 19:25 ` Andrew Morton
2004-04-09 2:41 ` Wim Coekaerts
2004-04-08 0:22 ` Andrea Arcangeli
[not found] <1IsMQ-3vi-35@gated-at.bofh.it>
[not found] ` <1IsMS-3vi-45@gated-at.bofh.it>
[not found] ` <1It5U-3J1-21@gated-at.bofh.it>
[not found] ` <1ItfE-3PL-3@gated-at.bofh.it>
[not found] ` <1ISQC-7Cv-5@gated-at.bofh.it>
2004-04-09 5:39 ` Andi Kleen
[not found] <1IL3l-1dP-35@gated-at.bofh.it>
[not found] ` <1IMik-2is-37@gated-at.bofh.it>
2004-04-08 19:20 ` Rajesh Venkatasubramanian
2004-04-08 19:48 ` Hugh Dickins
2004-04-08 19:57 ` Rajesh Venkatasubramanian
2004-04-08 19:52 ` Andrea Arcangeli
-- strict thread matches above, loose matches on Subject: below --
2004-04-06 13:33 Andi Kleen
2004-04-06 23:35 ` Paul Jackson
2004-04-08 20:12 ` Pavel Machek
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