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Subject: Re: [External] [RFC PATCH v1 3/6] mm, zone_type: create ZONE_NVM and
 fill into GFP_ZONE_TABLE
To:     Huaisheng HS1 Ye <yehs1@lenovo.com>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>
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        "colyli@suse.de" <colyli@suse.de>,
        NingTing Cheng <chengnt@lenovo.com>,
        Ocean HY1 He <hehy1@lenovo.com>,
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From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <ce3a6f37-3b13-0c35-6895-35156c7a290c@infradead.org>
Date:   Mon, 7 May 2018 21:43:30 -0700
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On 05/07/2018 07:33 PM, Huaisheng HS1 Ye wrote:
> diff --git a/mm/Kconfig b/mm/Kconfig
> index c782e8f..5fe1f63 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -687,6 +687,22 @@ config ZONE_DEVICE
>  
> +config ZONE_NVM
> +	bool "Manage NVDIMM (pmem) by memory management (EXPERIMENTAL)"
> +	depends on NUMA && X86_64

Hi,
I'm curious why this depends on NUMA. Couldn't it be useful in non-NUMA
(i.e., UMA) configs?

Thanks.

> +	depends on HAVE_MEMBLOCK_NODE_MAP
> +	depends on HAVE_MEMBLOCK
> +	depends on !IA32_EMULATION
> +	default n
> +
> +	help
> +	  This option allows you to use memory management subsystem to manage
> +	  NVDIMM (pmem). With it mm can arrange NVDIMMs into real physical zones
> +	  like NORMAL and DMA32. That means buddy system and swap can be used
> +	  directly to NVDIMM zone. This feature is beneficial to recover
> +	  dirty pages from power fail or system crash by storing write cache
> +	  to NVDIMM zone.


-- 
~Randy