From: Tejun Heo <tj@kernel.org>
To: Yinghai Lu <yinghai@kernel.org>
Cc: David Rientjes <rientjes@google.com>, Ingo Molnar <mingo@elte.hu>,
tglx@linutronix.de, "H. Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH x86/mm UPDATED] x86-64, NUMA: Fix distance table handling
Date: Wed, 2 Mar 2011 17:55:45 +0100 [thread overview]
Message-ID: <20110302165545.GR3319@htj.dyndns.org> (raw)
In-Reply-To: <4D6E7459.6050706@kernel.org>
On Wed, Mar 02, 2011 at 08:46:17AM -0800, Yinghai Lu wrote:
> > * I don't think it's gonna matter all that much. It's one time and
> > only used if emulation is enabled, but then again yeap MAX_NUMNODES
> > * MAX_NUMNODES can get quite high, but it looks way too complicated
> > for what it achieves. Just looping over enabled nodes should
> > achieve about the same thing in much simpler way, right?
>
> what kind of excuse to put inefficiency code there!
Complexity of a solution should match the benefit of the complexity.
Code complexity is one of the most important metrics that we need to
keep an eye on. If you don't do that, the code base becomes very ugly
and difficult to maintain very quickly. So, yes, some amount of
execution inefficiency is acceptable depending on circumstances.
Efficiency too is something which should be traded off against other
benefits.
In this case, it's not a performance critical path at all and similar
level of efficiency can be achieved in much simpler way, so let's do
that, okay?
Thanks.
--
tejun
next prev parent reply other threads:[~2011-03-02 16:55 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-24 14:51 [GIT PULL tip:x86/mm] Tejun Heo
2011-02-24 14:52 ` [GIT PULL tip:x86/mm] bootmem,x86: cleanup changes Tejun Heo
2011-02-24 19:08 ` [GIT PULL tip:x86/mm] Yinghai Lu
2011-02-24 19:23 ` Ingo Molnar
2011-02-24 19:28 ` Yinghai Lu
2011-02-24 19:32 ` Ingo Molnar
2011-02-24 19:46 ` Tejun Heo
2011-02-24 22:46 ` [patch] x86, mm: Fix size of numa_distance array David Rientjes
2011-02-24 23:30 ` Yinghai Lu
2011-02-24 23:31 ` David Rientjes
2011-02-25 9:05 ` Tejun Heo
2011-02-25 9:03 ` Tejun Heo
2011-02-25 10:58 ` Tejun Heo
2011-02-25 11:05 ` Tejun Heo
2011-02-25 9:11 ` [PATCH x86-mm] x86-64, NUMA: " Tejun Heo
2011-03-01 17:18 ` [GIT PULL tip:x86/mm] David Rientjes
2011-03-01 18:25 ` Tejun Heo
2011-03-01 22:19 ` Yinghai Lu
2011-03-02 9:17 ` Tejun Heo
2011-03-02 10:04 ` [PATCH x86/mm] x86-64, NUMA: Fix distance table handling Tejun Heo
2011-03-02 10:07 ` Ingo Molnar
2011-03-02 10:15 ` Tejun Heo
2011-03-02 10:36 ` Ingo Molnar
2011-03-02 10:25 ` [PATCH x86/mm UPDATED] " Tejun Heo
2011-03-02 10:39 ` [PATCH x86/mm] x86-64, NUMA: Better explain numa_distance handling Tejun Heo
2011-03-02 10:42 ` [PATCH UPDATED " Tejun Heo
2011-03-02 14:31 ` David Rientjes
2011-03-02 14:30 ` [PATCH x86/mm UPDATED] x86-64, NUMA: Fix distance table handling David Rientjes
2011-03-02 15:42 ` Tejun Heo
2011-03-02 21:12 ` Yinghai Lu
2011-03-02 21:36 ` Yinghai Lu
2011-03-03 20:07 ` David Rientjes
2011-03-04 14:32 ` Tejun Heo
2011-03-03 20:04 ` David Rientjes
2011-03-03 20:00 ` David Rientjes
2011-03-04 15:31 ` [PATCH x86/mm] x86-64, NUMA: Don't assume phys node 0 is always online in numa_emulation() handling Tejun Heo
2011-03-04 21:33 ` David Rientjes
2011-03-05 7:50 ` Tejun Heo
2011-03-05 15:50 ` [tip:x86/mm] x86-64, NUMA: Don't assume phys node 0 is always online in numa_emulation() tip-bot for Tejun Heo
2011-03-02 16:16 ` [PATCH x86/mm UPDATED] x86-64, NUMA: Fix distance table handling Yinghai Lu
2011-03-02 16:37 ` Tejun Heo
2011-03-02 16:46 ` Yinghai Lu
2011-03-02 16:55 ` Tejun Heo [this message]
2011-03-02 18:52 ` Yinghai Lu
2011-03-02 19:02 ` Tejun Heo
2011-03-02 19:06 ` Yinghai Lu
2011-03-02 19:13 ` Tejun Heo
2011-03-02 20:32 ` Yinghai Lu
2011-03-02 20:57 ` Tejun Heo
2011-03-02 21:14 ` Yinghai Lu
2011-03-03 6:17 ` Tejun Heo
2011-03-10 18:46 ` Yinghai Lu
2011-03-11 8:29 ` Tejun Heo
2011-03-11 8:33 ` Tejun Heo
2011-03-11 15:48 ` Yinghai Lu
2011-03-11 15:54 ` Tejun Heo
2011-03-11 18:02 ` Yinghai Lu
2011-03-11 18:19 ` Tejun Heo
2011-03-11 18:25 ` Yinghai Lu
2011-03-11 18:29 ` Tejun Heo
2011-03-11 18:45 ` Yinghai Lu
2011-03-11 9:31 ` [PATCH x86/mm] x86-64, NUMA: Don't call numa_set_distanc() for all possible node combinations during emulation Tejun Heo
2011-03-11 15:42 ` Yinghai Lu
2011-03-11 16:03 ` Tejun Heo
2011-03-11 19:05 ` Yinghai Lu
2011-03-02 10:43 ` [PATCH x86/mm] x86-64, NUMA: Fix distance table handling Ingo Molnar
2011-03-02 10:53 ` Tejun Heo
2011-03-02 10:59 ` Tejun Heo
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