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From: Andreas Schwab <schwab@suse.de>
To: Richard Knutsson <ricknu-0@student.ltu.se>
Cc: Vignesh Babu BM <vignesh.babu@wipro.com>,
	Kernel Janitors List <kernel-janitors@lists.osdl.org>,
	linux-mm@kvack.org, tony.luck@intel.com,
	linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [KJ] [PATCH] is_power_of_2 in ia64mm
Date: Fri, 16 Feb 2007 16:43:32 +0000	[thread overview]
Message-ID: <jeps8am4sr.fsf@sykes.suse.de> (raw)
In-Reply-To: <45D5DE6F.6030604@student.ltu.se> (Richard Knutsson's message of "Fri, 16 Feb 2007 17:40:15 +0100")

Richard Knutsson <ricknu-0@student.ltu.se> writes:

> Andreas Schwab wrote:
>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>   
>>> Andreas Schwab wrote:
>>>     
>>>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>>>         
>>>>> Vignesh Babu BM wrote:
>>>>>         
>>>>>> @@ -175,7 +176,7 @@ static int __init hugetlb_setup_sz(char *str)
>>>>>>  		tr_pages = 0x15557000UL;
>>>>>>   	size = memparse(str, &str);
>>>>>> -	if (*str || (size & (size-1)) || !(tr_pages & size) ||
>>>>>> +	if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
>>>>>>  		size <= PAGE_SIZE ||
>>>>>>  		size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
>>>>>>  		printk(KERN_WARNING "Invalid huge page size specified\n");
>>>>>>           
>>>>> As we talked about before; is this really correct? !is_power_of_2(0) =
>>>>> true while (0 & (0-1)) = 0.
>>>>>         
>>>> size = 0 is also covered by the next two conditions, so the overall value
>>>> does not change.
>>>>       
>>> Yes, but is it meant to state that 'size' is not a power of two?
>>>     
>>
>> What else can it mean?
>>   
> What about !one_or_less_bit()?

Obviously not.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."
_______________________________________________
Kernel-janitors mailing list
Kernel-janitors@lists.osdl.org
https://lists.osdl.org/mailman/listinfo/kernel-janitors

WARNING: multiple messages have this Message-ID (diff)
From: Andreas Schwab <schwab@suse.de>
To: Richard Knutsson <ricknu-0@student.ltu.se>
Cc: Vignesh Babu BM <vignesh.babu@wipro.com>,
	Kernel Janitors List <kernel-janitors@lists.osdl.org>,
	linux-mm@kvack.org, tony.luck@intel.com,
	linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [KJ] [PATCH] is_power_of_2 in ia64mm
Date: Fri, 16 Feb 2007 16:43:32 +0000	[thread overview]
Message-ID: <jeps8am4sr.fsf@sykes.suse.de> (raw)
In-Reply-To: <45D5DE6F.6030604@student.ltu.se> (Richard Knutsson's message of "Fri, 16 Feb 2007 17:40:15 +0100")

Richard Knutsson <ricknu-0@student.ltu.se> writes:

> Andreas Schwab wrote:
>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>   
>>> Andreas Schwab wrote:
>>>     
>>>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>>>         
>>>>> Vignesh Babu BM wrote:
>>>>>         
>>>>>> @@ -175,7 +176,7 @@ static int __init hugetlb_setup_sz(char *str)
>>>>>>  		tr_pages = 0x15557000UL;
>>>>>>   	size = memparse(str, &str);
>>>>>> -	if (*str || (size & (size-1)) || !(tr_pages & size) ||
>>>>>> +	if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
>>>>>>  		size <= PAGE_SIZE ||
>>>>>>  		size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
>>>>>>  		printk(KERN_WARNING "Invalid huge page size specified\n");
>>>>>>           
>>>>> As we talked about before; is this really correct? !is_power_of_2(0) =
>>>>> true while (0 & (0-1)) = 0.
>>>>>         
>>>> size = 0 is also covered by the next two conditions, so the overall value
>>>> does not change.
>>>>       
>>> Yes, but is it meant to state that 'size' is not a power of two?
>>>     
>>
>> What else can it mean?
>>   
> What about !one_or_less_bit()?

Obviously not.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

WARNING: multiple messages have this Message-ID (diff)
From: Andreas Schwab <schwab@suse.de>
To: Richard Knutsson <ricknu-0@student.ltu.se>
Cc: Vignesh Babu BM <vignesh.babu@wipro.com>,
	Kernel Janitors List <kernel-janitors@lists.osdl.org>,
	linux-mm@kvack.org, tony.luck@intel.com,
	linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [KJ] [PATCH] is_power_of_2 in ia64mm
Date: Fri, 16 Feb 2007 17:43:32 +0100	[thread overview]
Message-ID: <jeps8am4sr.fsf@sykes.suse.de> (raw)
In-Reply-To: <45D5DE6F.6030604@student.ltu.se> (Richard Knutsson's message of "Fri, 16 Feb 2007 17:40:15 +0100")

Richard Knutsson <ricknu-0@student.ltu.se> writes:

> Andreas Schwab wrote:
>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>   
>>> Andreas Schwab wrote:
>>>     
>>>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>>>         
>>>>> Vignesh Babu BM wrote:
>>>>>         
>>>>>> @@ -175,7 +176,7 @@ static int __init hugetlb_setup_sz(char *str)
>>>>>>  		tr_pages = 0x15557000UL;
>>>>>>   	size = memparse(str, &str);
>>>>>> -	if (*str || (size & (size-1)) || !(tr_pages & size) ||
>>>>>> +	if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
>>>>>>  		size <= PAGE_SIZE ||
>>>>>>  		size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
>>>>>>  		printk(KERN_WARNING "Invalid huge page size specified\n");
>>>>>>           
>>>>> As we talked about before; is this really correct? !is_power_of_2(0) ==
>>>>> true while (0 & (0-1)) == 0.
>>>>>         
>>>> size == 0 is also covered by the next two conditions, so the overall value
>>>> does not change.
>>>>       
>>> Yes, but is it meant to state that 'size' is not a power of two?
>>>     
>>
>> What else can it mean?
>>   
> What about !one_or_less_bit()?

Obviously not.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

WARNING: multiple messages have this Message-ID (diff)
From: Andreas Schwab <schwab@suse.de>
To: Richard Knutsson <ricknu-0@student.ltu.se>
Cc: Vignesh Babu BM <vignesh.babu@wipro.com>,
	Kernel Janitors List <kernel-janitors@lists.osdl.org>,
	linux-mm@kvack.org, tony.luck@intel.com,
	linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [KJ] [PATCH] is_power_of_2 in ia64mm
Date: Fri, 16 Feb 2007 17:43:32 +0100	[thread overview]
Message-ID: <jeps8am4sr.fsf@sykes.suse.de> (raw)
In-Reply-To: <45D5DE6F.6030604@student.ltu.se> (Richard Knutsson's message of "Fri, 16 Feb 2007 17:40:15 +0100")

Richard Knutsson <ricknu-0@student.ltu.se> writes:

> Andreas Schwab wrote:
>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>   
>>> Andreas Schwab wrote:
>>>     
>>>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>>>         
>>>>> Vignesh Babu BM wrote:
>>>>>         
>>>>>> @@ -175,7 +176,7 @@ static int __init hugetlb_setup_sz(char *str)
>>>>>>  		tr_pages = 0x15557000UL;
>>>>>>   	size = memparse(str, &str);
>>>>>> -	if (*str || (size & (size-1)) || !(tr_pages & size) ||
>>>>>> +	if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
>>>>>>  		size <= PAGE_SIZE ||
>>>>>>  		size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
>>>>>>  		printk(KERN_WARNING "Invalid huge page size specified\n");
>>>>>>           
>>>>> As we talked about before; is this really correct? !is_power_of_2(0) ==
>>>>> true while (0 & (0-1)) == 0.
>>>>>         
>>>> size == 0 is also covered by the next two conditions, so the overall value
>>>> does not change.
>>>>       
>>> Yes, but is it meant to state that 'size' is not a power of two?
>>>     
>>
>> What else can it mean?
>>   
> What about !one_or_less_bit()?

Obviously not.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstrasse 5, 90409 Nurnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

--
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  reply	other threads:[~2007-02-16 16:43 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-16 12:03 [KJ][PATCH] is_power_of_2 in ia64mm Vignesh Babu BM
2007-02-16 12:15 ` Vignesh Babu BM
2007-02-16 12:15 ` [KJ] [PATCH] " Vignesh Babu BM
2007-02-16 12:03 ` [KJ][PATCH] " Vignesh Babu BM
2007-02-16 15:02 ` [KJ] [PATCH] " Richard Knutsson
2007-02-16 15:02   ` Richard Knutsson
2007-02-16 15:02   ` Richard Knutsson
2007-02-16 15:02   ` Richard Knutsson
2007-02-16 15:13   ` Andreas Schwab
2007-02-16 15:13     ` Andreas Schwab
2007-02-16 15:13     ` Andreas Schwab
2007-02-16 15:13     ` Andreas Schwab
2007-02-16 15:57     ` Richard Knutsson
2007-02-16 15:57       ` Richard Knutsson
2007-02-16 15:57       ` Richard Knutsson
2007-02-16 15:57       ` Richard Knutsson
2007-02-16 15:59       ` Andreas Schwab
2007-02-16 15:59         ` Andreas Schwab
2007-02-16 15:59         ` Andreas Schwab
2007-02-16 15:59         ` Andreas Schwab
2007-02-16 16:40         ` Richard Knutsson
2007-02-16 16:40           ` Richard Knutsson
2007-02-16 16:40           ` Richard Knutsson
2007-02-16 16:40           ` Richard Knutsson
2007-02-16 16:43           ` Andreas Schwab [this message]
2007-02-16 16:43             ` Andreas Schwab
2007-02-16 16:43             ` Andreas Schwab
2007-02-16 16:43             ` Andreas Schwab
2007-02-16 17:06           ` Robert P. J. Day
2007-02-16 17:06             ` Robert P. J. Day
2007-02-16 17:06             ` Robert P. J. Day
2007-02-16 17:06             ` Robert P. J. Day
2007-02-16 17:36             ` Richard Knutsson
2007-02-16 17:36               ` Richard Knutsson
2007-02-16 17:36               ` Richard Knutsson
2007-02-16 17:36               ` Richard Knutsson
2007-02-16 16:58       ` Robert P. J. Day
2007-02-16 16:58         ` Robert P. J. Day
2007-02-16 16:58         ` Robert P. J. Day
2007-02-16 16:58         ` Robert P. J. Day
2007-02-16 15:27   ` Boot time Bluetooth BUG: warning: (value > m) at hid-core.c:793 Fortier,Vincent [Montreal]
2007-02-18 21:23     ` Jiri Kosina
2007-02-19  0:25       ` Marcel Holtmann
2007-02-19  9:36         ` Jiri Kosina
2007-02-27 15:54         ` Jiri Kosina
2007-02-27 16:12           ` Fortier,Vincent [Montreal]
     [not found]             ` <Pine.LNX.4.64.0702271713220.10496@twin.jikos.cz>
2007-02-27 20:35               ` Fortier,Vincent [Montreal]

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