Commit 5e6bbde9 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: introduce mempool for {,de}compress intermediate page allocation 



If compression feature is on, in scenario of no enough free memory,
page refault ratio is higher than before, the root cause is:
- {,de}compression flow needs to allocate intermediate pages to store
compressed data in cluster, so during their allocation, vm may reclaim
mmaped pages.
- if above reclaimed pages belong to compressed cluster, during its
refault, it may cause more intermediate pages allocation, result in
reclaiming more mmaped pages.

So this patch introduces a mempool for intermediate page allocation,
in order to avoid high refault ratio, by default, number of
preallocated page in pool is 512, user can change the number by
assigning 'num_compress_pages' parameter during module initialization.

Ma Feng found warnings in the original patch and fixed like below.

Fix the following sparse warning:
fs/f2fs/compress.c:501:5: warning: symbol 'num_compress_pages' was not declared.
 Should it be static?
fs/f2fs/compress.c:530:6: warning: symbol 'f2fs_compress_free_page' was not
declared. Should it be static?

Reported-by: default avatarHulk Robot <hulkci@huawei.com>
Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarMa Feng <mafeng.ma@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent c1c63387

fs/f2fs/compress.c

+42 −22
Original line number Diff line number Diff line
@@ -65,15 +65,6 @@ static void f2fs_set_compressed_page(struct page *page, 
	page->mapping = inode->i_mapping;

}



static void f2fs_put_compressed_page(struct page *page)

{

	set_page_private(page, (unsigned long)NULL);

	ClearPagePrivate(page);

	page->mapping = NULL;

	unlock_page(page);

	put_page(page);

}



static void f2fs_drop_rpages(struct compress_ctx *cc, int len, bool unlock)

{

	int i;
@@ -476,17 +467,47 @@ bool f2fs_is_compress_backend_ready(struct inode *inode) 
	return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];

}



static struct page *f2fs_grab_page(void)

static mempool_t *compress_page_pool = NULL;

static int num_compress_pages = 512;

module_param(num_compress_pages, uint, 0444);

MODULE_PARM_DESC(num_compress_pages,

		"Number of intermediate compress pages to preallocate");



int f2fs_init_compress_mempool(void)

{

	compress_page_pool = mempool_create_page_pool(num_compress_pages, 0);

	if (!compress_page_pool)

		return -ENOMEM;



	return 0;

}



void f2fs_destroy_compress_mempool(void)

{

	mempool_destroy(compress_page_pool);

}



static struct page *f2fs_compress_alloc_page(void)

{

	struct page *page;



	page = alloc_page(GFP_NOFS);

	if (!page)

		return NULL;

	page = mempool_alloc(compress_page_pool, GFP_NOFS);

	lock_page(page);



	return page;

}



static void f2fs_compress_free_page(struct page *page)

{

	if (!page)

		return;

	set_page_private(page, (unsigned long)NULL);

	ClearPagePrivate(page);

	page->mapping = NULL;

	unlock_page(page);

	mempool_free(page, compress_page_pool);

}



static int f2fs_compress_pages(struct compress_ctx *cc)

{

	struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
@@ -516,7 +537,7 @@ static int f2fs_compress_pages(struct compress_ctx *cc) 
	}



	for (i = 0; i < cc->nr_cpages; i++) {

		cc->cpages[i] = f2fs_grab_page();

		cc->cpages[i] = f2fs_compress_alloc_page();

		if (!cc->cpages[i]) {

			ret = -ENOMEM;

			goto out_free_cpages;
@@ -561,7 +582,7 @@ static int f2fs_compress_pages(struct compress_ctx *cc) 
	vunmap(cc->rbuf);



	for (i = nr_cpages; i < cc->nr_cpages; i++) {

		f2fs_put_compressed_page(cc->cpages[i]);

		f2fs_compress_free_page(cc->cpages[i]);

		cc->cpages[i] = NULL;

	}
@@ -581,7 +602,7 @@ out_vunmap_rbuf: 
out_free_cpages:

	for (i = 0; i < cc->nr_cpages; i++) {

		if (cc->cpages[i])

			f2fs_put_compressed_page(cc->cpages[i]);

			f2fs_compress_free_page(cc->cpages[i]);

	}

	kfree(cc->cpages);

	cc->cpages = NULL;
@@ -1183,7 +1204,7 @@ void f2fs_compress_write_end_io(struct bio *bio, struct page *page) 
	if (unlikely(bio->bi_status))

		mapping_set_error(cic->inode->i_mapping, -EIO);



	f2fs_put_compressed_page(page);

	f2fs_compress_free_page(page);



	dec_page_count(sbi, F2FS_WB_DATA);
@@ -1344,7 +1365,7 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc) 
	for (i = 0; i < dic->nr_cpages; i++) {

		struct page *page;



		page = f2fs_grab_page();

		page = f2fs_compress_alloc_page();

		if (!page)

			goto out_free;
@@ -1364,7 +1385,7 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc) 
			continue;

		}



		dic->tpages[i] = f2fs_grab_page();

		dic->tpages[i] = f2fs_compress_alloc_page();

		if (!dic->tpages[i])

			goto out_free;

	}
@@ -1386,8 +1407,7 @@ void f2fs_free_dic(struct decompress_io_ctx *dic) 
				continue;

			if (!dic->tpages[i])

				continue;

			unlock_page(dic->tpages[i]);

			put_page(dic->tpages[i]);

			f2fs_compress_free_page(dic->tpages[i]);

		}

		kfree(dic->tpages);

	}
@@ -1396,7 +1416,7 @@ void f2fs_free_dic(struct decompress_io_ctx *dic) 
		for (i = 0; i < dic->nr_cpages; i++) {

			if (!dic->cpages[i])

				continue;

			f2fs_put_compressed_page(dic->cpages[i]);

			f2fs_compress_free_page(dic->cpages[i]);

		}

		kfree(dic->cpages);

	}

fs/f2fs/f2fs.h

+4 −0
Original line number Diff line number Diff line
@@ -3829,6 +3829,8 @@ bool f2fs_compress_write_end(struct inode *inode, void *fsdata, 
int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock);

void f2fs_compress_write_end_io(struct bio *bio, struct page *page);

bool f2fs_is_compress_backend_ready(struct inode *inode);

int f2fs_init_compress_mempool(void);

void f2fs_destroy_compress_mempool(void);

void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity);

bool f2fs_cluster_is_empty(struct compress_ctx *cc);

bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index);
@@ -3862,6 +3864,8 @@ static inline struct page *f2fs_compress_control_page(struct page *page) 
	WARN_ON_ONCE(1);

	return ERR_PTR(-EINVAL);

}

static inline int f2fs_init_compress_mempool(void) { return 0; }

static inline void f2fs_destroy_compress_mempool(void) { }

#endif



static inline void set_compress_context(struct inode *inode)

fs/f2fs/super.c

+6 −0
Original line number Diff line number Diff line
@@ -3879,7 +3879,12 @@ static int __init init_f2fs_fs(void) 
	err = f2fs_init_bioset();

	if (err)

		goto free_bio_enrty_cache;

	err = f2fs_init_compress_mempool();

	if (err)

		goto free_bioset;

	return 0;

free_bioset:

	f2fs_destroy_bioset();

free_bio_enrty_cache:

	f2fs_destroy_bio_entry_cache();

free_post_read:
@@ -3907,6 +3912,7 @@ fail: 


static void __exit exit_f2fs_fs(void)

{

	f2fs_destroy_compress_mempool();

	f2fs_destroy_bioset();

	f2fs_destroy_bio_entry_cache();

	f2fs_destroy_post_read_processing();

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