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From: Yinghai Lu <yinghai@kernel.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.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: Sat, 05 Mar 2011 17:20:02 -0800	[thread overview]
Message-ID: <4D72E142.3000305@kernel.org> (raw)
In-Reply-To: <1299372594.8833.966.camel@pasglop>

On 03/05/2011 04:49 PM, Benjamin Herrenschmidt wrote:
> 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.

ok.

WARNING: multiple messages have this Message-ID (diff)
From: Yinghai Lu <yinghai@kernel.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.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: Sat, 05 Mar 2011 17:20:02 -0800	[thread overview]
Message-ID: <4D72E142.3000305@kernel.org> (raw)
In-Reply-To: <1299372594.8833.966.camel@pasglop>

On 03/05/2011 04:49 PM, Benjamin Herrenschmidt wrote:
> 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.

ok.

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  reply	other threads:[~2011-03-06  2:04 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-05  4:05 [RFC] memblock; Properly handle overlaps Benjamin Herrenschmidt
2011-03-05  4:05 ` Benjamin Herrenschmidt
2011-03-05  5:46 ` Yinghai Lu
2011-03-05  5:46   ` Yinghai Lu
2011-03-05  7:56   ` Benjamin Herrenschmidt
2011-03-05  7:56     ` Benjamin Herrenschmidt
2011-03-05 19:14     ` Yinghai Lu
2011-03-05 19:14       ` Yinghai Lu
2011-03-05 21:37       ` Benjamin Herrenschmidt
2011-03-05 21:37         ` Benjamin Herrenschmidt
2011-03-05 21:50         ` Benjamin Herrenschmidt
2011-03-05 21:50           ` Benjamin Herrenschmidt
2011-03-05 22:08           ` Benjamin Herrenschmidt
2011-03-05 22:08             ` Benjamin Herrenschmidt
2011-03-05 22:01         ` Yinghai Lu
2011-03-05 22:01           ` Yinghai Lu
2011-03-05 22:19           ` Benjamin Herrenschmidt
2011-03-05 22:19             ` Benjamin Herrenschmidt
2011-03-05 23:20             ` Yinghai Lu
2011-03-05 23:20               ` Yinghai Lu
2011-03-06  0:49               ` Benjamin Herrenschmidt
2011-03-06  0:49                 ` Benjamin Herrenschmidt
2011-03-06  1:20                 ` Yinghai Lu [this message]
2011-03-06  1:20                   ` Yinghai Lu

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