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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Yinghai Lu <yinghai@kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-mm@kvack.org, Russell King <linux@arm.linux.org.uk>
Subject: Re: [RFC] memblock; Properly handle overlaps
Date: Sun, 06 Mar 2011 11:49:54 +1100	[thread overview]
Message-ID: <1299372594.8833.966.camel@pasglop> (raw)
In-Reply-To: <4D72C552.4050406@kernel.org>

On Sat, 2011-03-05 at 15:20 -0800, Yinghai Lu wrote:
> 
> maybe we can omit rgn->size == 0 checking here.
> with that case, dummy array will go though to some extra checking.
> 
> if (rgn->base <= base && rend >= end)
> if (base < rgn->base && end >= rgn->base) {
> if (base <= rend && end >= rend) {
> 
> but we can spare more checking regarding
>         rgn->size == 0

Well, the array can be collasped to dummy by the removal of the last
block when doing a top overlap, then on the next loop around, we can
potentially hit the if (base <= rend && end >= rend) test, and loop
again no ?

I'd rather keep the test in .. won't hurt.

Cheers,
Ben.

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  reply	other threads:[~2011-03-06  0:50 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-05  4:05 [RFC] memblock; Properly handle overlaps Benjamin Herrenschmidt
2011-03-05  5:46 ` Yinghai Lu
2011-03-05  7:56   ` Benjamin Herrenschmidt
2011-03-05 19:14     ` Yinghai Lu
2011-03-05 21:37       ` Benjamin Herrenschmidt
2011-03-05 21:50         ` Benjamin Herrenschmidt
2011-03-05 22:08           ` Benjamin Herrenschmidt
2011-03-05 22:01         ` Yinghai Lu
2011-03-05 22:19           ` Benjamin Herrenschmidt
2011-03-05 23:20             ` Yinghai Lu
2011-03-06  0:49               ` Benjamin Herrenschmidt [this message]
2011-03-06  1:20                 ` Yinghai Lu

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