Commit eaa9172a authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: get rid of ->lru usage 

Currently, ->lru is a way to arrange non-LRU pages and has some
in-kernel users. In order to minimize noticable issues of page
reclaim and cache thrashing under high memory presure, limited
temporary pages were all chained with ->lru and can be reused
during the request. However, it seems that ->lru could be removed
when folio is landing.

Let's use page->private to chain temporary pages for now instead
and transform EROFS formally after the topic of the folio / file
page design is finalized.

Link: https://lore.kernel.org/r/20211022090120.14675-1-hsiangkao@linux.alibaba.com


Cc: Matthew Wilcox <willy@infradead.org>
Reviewed-by: default avatarKent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 622ceadd

fs/erofs/compress.h

+5 −6
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ struct z_erofs_decompress_req { 


struct z_erofs_decompressor {

	int (*decompress)(struct z_erofs_decompress_req *rq,

			  struct list_head *pagepool);

			  struct page **pagepool);

	char *name;

};
@@ -64,7 +64,7 @@ static inline bool z_erofs_is_shortlived_page(struct page *page) 
	return true;

}



static inline bool z_erofs_put_shortlivedpage(struct list_head *pagepool,

static inline bool z_erofs_put_shortlivedpage(struct page **pagepool,

					      struct page *page)

{

	if (!z_erofs_is_shortlived_page(page))
@@ -75,8 +75,7 @@ static inline bool z_erofs_put_shortlivedpage(struct list_head *pagepool, 
		put_page(page);

	} else {

		/* follow the pcluster rule above. */

		set_page_private(page, 0);

		list_add(&page->lru, pagepool);

		erofs_pagepool_add(pagepool, page);

	}

	return true;

}
@@ -89,9 +88,9 @@ static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi, 
}



int z_erofs_decompress(struct z_erofs_decompress_req *rq,

		       struct list_head *pagepool);

		       struct page **pagepool);



/* prototypes for specific algorithms */

int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,

			    struct list_head *pagepool);

			    struct page **pagepool);

#endif

fs/erofs/decompressor.c

+4 −4
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ int z_erofs_load_lz4_config(struct super_block *sb, 
 * all physical pages are consecutive, which can be seen for moderate CR.

 */

static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq,

					struct list_head *pagepool)

					struct page **pagepool)

{

	const unsigned int nr =

		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -254,7 +254,7 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq, 
}



static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,

				  struct list_head *pagepool)

				  struct page **pagepool)

{

	const unsigned int nrpages_out =

		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -296,7 +296,7 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, 
}



static int z_erofs_shifted_transform(struct z_erofs_decompress_req *rq,

				     struct list_head *pagepool)

				     struct page **pagepool)

{

	const unsigned int nrpages_out =

		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -352,7 +352,7 @@ static struct z_erofs_decompressor decompressors[] = { 
};



int z_erofs_decompress(struct z_erofs_decompress_req *rq,

		       struct list_head *pagepool)

		       struct page **pagepool)

{

	return decompressors[rq->alg].decompress(rq, pagepool);

}

fs/erofs/decompressor_lzma.c

+1 −1
Original line number Diff line number Diff line
@@ -150,7 +150,7 @@ int z_erofs_load_lzma_config(struct super_block *sb, 
}



int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,

			    struct list_head *pagepool)

			    struct page **pagepool)

{

	const unsigned int nrpages_out =

		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;

fs/erofs/internal.h

+8 −1
Original line number Diff line number Diff line
@@ -499,7 +499,14 @@ void erofs_pcpubuf_init(void); 
void erofs_pcpubuf_exit(void);



/* utils.c / zdata.c */

struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);

struct page *erofs_allocpage(struct page **pagepool, gfp_t gfp);

static inline void erofs_pagepool_add(struct page **pagepool,

		struct page *page)

{

	set_page_private(page, (unsigned long)*pagepool);

	*pagepool = page;

}

void erofs_release_pages(struct page **pagepool);



#ifdef CONFIG_EROFS_FS_ZIP

int erofs_workgroup_put(struct erofs_workgroup *grp);

fs/erofs/pcpubuf.c

+3 −3
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ int erofs_pcpubuf_growsize(unsigned int nrpages) 
{

	static DEFINE_MUTEX(pcb_resize_mutex);

	static unsigned int pcb_nrpages;

	LIST_HEAD(pagepool);

	struct page *pagepool = NULL;

	int delta, cpu, ret, i;



	mutex_lock(&pcb_resize_mutex);
@@ -102,13 +102,13 @@ int erofs_pcpubuf_growsize(unsigned int nrpages) 
			vunmap(old_ptr);

free_pagearray:

		while (i)

			list_add(&oldpages[--i]->lru, &pagepool);

			erofs_pagepool_add(&pagepool, oldpages[--i]);

		kfree(oldpages);

		if (ret)

			break;

	}

	pcb_nrpages = nrpages;

	put_pages_list(&pagepool);

	erofs_release_pages(&pagepool);

out:

	mutex_unlock(&pcb_resize_mutex);

	return ret;