From: David Sterba Date: Mon, 14 Jun 2021 20:22:22 +0000 (+0200) Subject: btrfs: drop from __GFP_HIGHMEM all allocations X-Git-Tag: accepted/tizen/unified/20230118.172025~6109^2~129 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b0ee5e1ec44afda53aaa37f8c41ad00d170506cb;p=platform%2Fkernel%2Flinux-rpi.git btrfs: drop from __GFP_HIGHMEM all allocations The highmem flag is used for allocating pages for compression and for raid56 pages. The high memory makes sense on 32bit systems but is not without problems. On 64bit system's it's just another layer of wrappers. The time the pages are allocated for compression or raid56 is relatively short (about a transaction commit), so the pages are not blocked indefinitely. As the number of pages depends on the amount of data being written/read, there's a theoretical problem. A fast device on a 32bit system could use most of the low memory pool, while with the highmem allocation that would not happen. This was possibly the original idea long time ago, but nowadays we optimize for 64bit systems. This patch removes all usage of the __GFP_HIGHMEM flag for page allocation, the kmap/kunmap are still in place and will be removed in followup patches. Remaining is masking out the bit in alloc_extent_state and __lookup_free_space_inode, that can safely stay. Signed-off-by: David Sterba --- diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 30d82cd..49fdec4 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -721,8 +721,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, goto fail1; for (pg_index = 0; pg_index < nr_pages; pg_index++) { - cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS | - __GFP_HIGHMEM); + cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS); if (!cb->compressed_pages[pg_index]) { faili = pg_index - 1; ret = BLK_STS_RESOURCE; diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index cd042c7..2bebb60 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -146,7 +146,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, * store the size of all chunks of compressed data in * the first 4 bytes */ - out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + out_page = alloc_page(GFP_NOFS); if (out_page == NULL) { ret = -ENOMEM; goto out; @@ -216,7 +216,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, goto out; } - out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + out_page = alloc_page(GFP_NOFS); if (out_page == NULL) { ret = -ENOMEM; goto out; diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 244d499..a40a45a 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -1035,7 +1035,7 @@ static int alloc_rbio_pages(struct btrfs_raid_bio *rbio) for (i = 0; i < rbio->nr_pages; i++) { if (rbio->stripe_pages[i]) continue; - page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + page = alloc_page(GFP_NOFS); if (!page) return -ENOMEM; rbio->stripe_pages[i] = page; @@ -1054,7 +1054,7 @@ static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio) for (; i < rbio->nr_pages; i++) { if (rbio->stripe_pages[i]) continue; - page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + page = alloc_page(GFP_NOFS); if (!page) return -ENOMEM; rbio->stripe_pages[i] = page; @@ -2300,7 +2300,7 @@ static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio) if (rbio->stripe_pages[index]) continue; - page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + page = alloc_page(GFP_NOFS); if (!page) return -ENOMEM; rbio->stripe_pages[index] = page; @@ -2350,14 +2350,14 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio, if (!need_check) goto writeback; - p_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + p_page = alloc_page(GFP_NOFS); if (!p_page) goto cleanup; SetPageUptodate(p_page); if (has_qstripe) { /* RAID6, allocate and map temp space for the Q stripe */ - q_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + q_page = alloc_page(GFP_NOFS); if (!q_page) { __free_page(p_page); goto cleanup; diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index c3fa7d3..2c792bc 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -121,7 +121,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, workspace->strm.total_in = 0; workspace->strm.total_out = 0; - out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + out_page = alloc_page(GFP_NOFS); if (out_page == NULL) { ret = -ENOMEM; goto out; @@ -202,7 +202,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -E2BIG; goto out; } - out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + out_page = alloc_page(GFP_NOFS); if (out_page == NULL) { ret = -ENOMEM; goto out; @@ -240,7 +240,7 @@ int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -E2BIG; goto out; } - out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + out_page = alloc_page(GFP_NOFS); if (out_page == NULL) { ret = -ENOMEM; goto out; diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c index 3e26b46..9451d2b 100644 --- a/fs/btrfs/zstd.c +++ b/fs/btrfs/zstd.c @@ -405,7 +405,7 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, /* Allocate and map in the output buffer */ - out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + out_page = alloc_page(GFP_NOFS); if (out_page == NULL) { ret = -ENOMEM; goto out; @@ -452,7 +452,7 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -E2BIG; goto out; } - out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + out_page = alloc_page(GFP_NOFS); if (out_page == NULL) { ret = -ENOMEM; goto out; @@ -512,7 +512,7 @@ int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, ret = -E2BIG; goto out; } - out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); + out_page = alloc_page(GFP_NOFS); if (out_page == NULL) { ret = -ENOMEM; goto out;