linux-kernel - Re: [PATCH 2/2] x86,mm,64bit: Round up memory boundary for init_memory_mapping

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4D680F77.5060107@kernel.org>
Date:	Fri, 25 Feb 2011 12:22:15 -0800
From:	Yinghai Lu <yinghai@...nel.org>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Tejun Heo <tj@...nel.org>, Ingo Molnar <mingo@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] x86,mm,64bit: Round up memory boundary for init_memory_mapping_high()

On 02/25/2011 02:03 AM, Ingo Molnar wrote:
> 
> * Yinghai Lu <yinghai@...nel.org> wrote:
> 
>>  init_memory_mapping_active_regions(unsigned long start, unsigned long end)
>>  {
>>  	struct mapping_work_data data;
>> +	int use_gbpages;
>> +
>> +	/* see init_memory_mapping() for the setting */
>> +#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
>> +	use_gbpages = 0;
>> +#else
>> +	use_gbpages = direct_gbpages;
>> +#endif
> 
> Sigh. You should *never* ever even think about writing such code. It only results in 
> crap, and in crap duplicated elsewhere as well:
> 
> if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
>         /*
>          * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
>          * This will simplify cpa(), which otherwise needs to support splitting
>          * large pages into small in interrupt context, etc.
>          */
>         use_pse = use_gbpages = 0;
> #else
>         use_pse = cpu_has_pse;
>         use_gbpages = direct_gbpages;
> #endif

sorry, actually i copied from there.

or i could add max_map_unit_size variable?

Thanks

Yinghai


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/