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From: Coly Li <colyli@suse.de>
To: Qiaowei Ren <qiaowei.ren@intel.com>, Jianpeng Ma <jianpeng.ma@intel.com>
Cc: linux-bcache@vger.kernel.org
Subject: Re: [bch-nvm-pages v7 3/6] bcache: initialization of the buddy
Date: Mon, 29 Mar 2021 19:10:04 +0800	[thread overview]
Message-ID: <e52b3a34-b394-0d16-56b9-edb1e5ba9933@suse.de> (raw)
In-Reply-To: <20210317151029.40735-4-qiaowei.ren@intel.com>

On 3/17/21 11:10 PM, Qiaowei Ren wrote:
> From: Jianpeng Ma <jianpeng.ma@intel.com>
> 
> This nvm pages allocator will implement the simple buddy to manage the
> nvm address space. This patch initializes this buddy for new namespace.
> 
> the unit of alloc/free of the buddy is page. DAX device has their
> struct page(in dram or PMEM).
> 
> 	struct {        /* ZONE_DEVICE pages */
> 		/** @pgmap: Points to the hosting device page map. */
> 		struct dev_pagemap *pgmap;
> 		void *zone_device_data;
> 		/*
> 		 * ZONE_DEVICE private pages are counted as being
> 		 * mapped so the next 3 words hold the mapping, index,
> 		 * and private fields from the source anonymous or
> 		 * page cache page while the page is migrated to device
> 		 * private memory.
> 		 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also
> 		 * use the mapping, index, and private fields when
> 		 * pmem backed DAX files are mapped.
> 		 */
> 	};
> 
> ZONE_DEVICE pages only use pgmap. Other 4 words[16/32 bytes] don't use.
> So the second/third word will be used as 'struct list_head ' which list
> in buddy. The fourth word(that is normal struct page::index) store pgoff
> which the page-offset in the dax device. And the fifth word (that is
> normal struct page::private) store order of buddy. page_type will be used
> to store buddy flags.
> 
> Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
> Co-authored-by: Qiaowei Ren <qiaowei.ren@intel.com>
> ---
>  drivers/md/bcache/nvm-pages.c   | 142 +++++++++++++++++++++++++++++++-
>  drivers/md/bcache/nvm-pages.h   |   6 ++
>  include/uapi/linux/bcache-nvm.h |   8 ++
>  3 files changed, 152 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/md/bcache/nvm-pages.c b/drivers/md/bcache/nvm-pages.c
> index 9335371c9d91..1f99965920a1 100644
> --- a/drivers/md/bcache/nvm-pages.c
> +++ b/drivers/md/bcache/nvm-pages.c
> @@ -41,6 +41,10 @@ static void release_nvm_namespaces(struct bch_nvm_set *nvm_set)
>  	for (i = 0; i < nvm_set->total_namespaces_nr; i++) {
>  		ns = nvm_set->nss[i];
>  		if (ns) {
> +			kvfree(ns->pages_bitmap);
> +			if (ns->pgalloc_recs_bitmap)
> +				bitmap_free(ns->pgalloc_recs_bitmap);
> +
>  			blkdev_put(ns->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXEC);
>  			kfree(ns);
>  		}
> @@ -55,17 +59,122 @@ static void release_nvm_set(struct bch_nvm_set *nvm_set)
>  	kfree(nvm_set);
>  }
>  
> +static struct page *nvm_vaddr_to_page(struct bch_nvm_namespace *ns, void *addr)
> +{
> +	return virt_to_page(addr);
> +}
> +
> +static void *nvm_pgoff_to_vaddr(struct bch_nvm_namespace *ns, pgoff_t pgoff)
> +{
> +	return ns->kaddr + (pgoff << PAGE_SHIFT);
> +}
> +
> +static inline void remove_owner_space(struct bch_nvm_namespace *ns,
> +					pgoff_t pgoff, u32 nr)
> +{
> +	bitmap_set(ns->pages_bitmap, pgoff, nr);
> +}
> +
>  static int init_owner_info(struct bch_nvm_namespace *ns)
>  {
>  	struct bch_owner_list_head *owner_list_head = ns->sb->owner_list_head;
> +	struct bch_nvm_pgalloc_recs *sys_recs;
> +	int i, j, k, rc = 0;
>  
>  	mutex_lock(&only_set->lock);
>  	only_set->owner_list_head = owner_list_head;
>  	only_set->owner_list_size = owner_list_head->size;
>  	only_set->owner_list_used = owner_list_head->used;
> +
> +	/*remove used space*/
> +	remove_owner_space(ns, 0, ns->pages_offset/ns->page_size);
> +
> +	sys_recs = ns->kaddr + BCH_NVM_PAGES_SYS_RECS_HEAD_OFFSET;
> +	// suppose no hole in array

We don't use such code comments format, please follow the comments style
of existing bcache code.

There are also other locations using "//" for code comments, they should
be modified as well.

Thanks.

Coly Li


[snipped]

  reply	other threads:[~2021-03-29 11:11 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-17 15:10 [bch-nvm-pages v7 0/6] nvm page allocator for bcache Qiaowei Ren
2021-03-17 15:10 ` [bch-nvm-pages v7 1/6] bcache: add initial data structures for nvm pages Qiaowei Ren
2021-03-29  5:47   ` Coly Li
2021-03-17 15:10 ` [bch-nvm-pages v7 2/6] bcache: initialize the nvm pages allocator Qiaowei Ren
2021-03-29  5:54   ` Coly Li
2021-04-05 15:14     ` Coly Li
2021-03-17 15:10 ` [bch-nvm-pages v7 3/6] bcache: initialization of the buddy Qiaowei Ren
2021-03-29 11:10   ` Coly Li [this message]
2021-03-30  2:13     ` Ma, Jianpeng
2021-03-17 15:10 ` [bch-nvm-pages v7 4/6] bcache: bch_nvm_alloc_pages() " Qiaowei Ren
2021-03-29 10:01   ` Coly Li
2021-03-17 15:10 ` [bch-nvm-pages v7 5/6] bcache: bch_nvm_free_pages() " Qiaowei Ren
2021-03-17 15:10 ` [bch-nvm-pages v7 6/6] bcache: get allocated pages from specific owner Qiaowei Ren
2021-03-23 13:24 ` [bch-nvm-pages v7 0/6] nvm page allocator for bcache Coly Li

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