From: gaoxiang25@huawei.com (Gao Xiang)
Subject: [PATCH v6 21/24] erofs: introduce LZ4 decompression inplace
Date: Fri, 2 Aug 2019 20:53:44 +0800 [thread overview]
Message-ID: <20190802125347.166018-22-gaoxiang25@huawei.com> (raw)
In-Reply-To: <20190802125347.166018-1-gaoxiang25@huawei.com>
compressed data will be usually loaded into last pages of
the extent (the last page for 4k) for in-place decompression
(more specifically, in-place IO), as ilustration below,
start of compressed logical extent
| end of this logical extent
| |
______v___________________________v________
... | page 6 | page 7 | page 8 | page 9 | ...
|__________|__________|__________|__________|
. ^ . ^
. |compressed|
. | data |
. . .
|< dstsize >|<margin>|
oend iend
op ip
Therefore, it's possible to do decompression inplace (thus no
memcpy at all) if the margin is sufficient and safe enough [1],
and it can be implemented only for fixed-size output compression
compared with fixed-size input compression.
No memcpy for most of in-place IO (about 99% of enwik9) after
decompression inplace is implemented and sequential read will
be improved of course (see the following patches for test results).
[1] https://github.com/lz4/lz4/commit/b17f578a919b7e6b078cede2d52be29dd48c8e8c
https://github.com/lz4/lz4/commit/5997e139f53169fa3a1c1b4418d2452a90b01602
Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
fs/erofs/decompressor.c | 36 ++++++++++++++++++++++++++++++++----
fs/erofs/erofs_fs.h | 2 +-
2 files changed, 33 insertions(+), 5 deletions(-)
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 244afb29907d..1e9e1359e40c 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -15,6 +15,9 @@
#endif
#define LZ4_MAX_DISTANCE_PAGES (DIV_ROUND_UP(LZ4_DISTANCE_MAX, PAGE_SIZE) + 1)
+#ifndef LZ4_DECOMPRESS_INPLACE_MARGIN
+#define LZ4_DECOMPRESS_INPLACE_MARGIN(srcsize) (((srcsize) >> 8) + 32)
+#endif
struct z_erofs_decompressor {
/*
@@ -117,7 +120,7 @@ static int lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
{
unsigned int inputmargin, inlen;
u8 *src;
- bool copied;
+ bool copied, support_0padding;
int ret;
if (rq->inputsize > PAGE_SIZE)
@@ -125,13 +128,38 @@ static int lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
src = kmap_atomic(*rq->in);
inputmargin = 0;
+ support_0padding = false;
+
+ /* decompression inplace is only safe when 0padding is enabled */
+ if (EROFS_SB(rq->sb)->requirements & EROFS_REQUIREMENT_LZ4_0PADDING) {
+ support_0padding = true;
+
+ while (!src[inputmargin & ~PAGE_MASK])
+ if (!(++inputmargin & ~PAGE_MASK))
+ break;
+
+ if (inputmargin >= rq->inputsize) {
+ kunmap_atomic(src);
+ return -EIO;
+ }
+ }
copied = false;
inlen = rq->inputsize - inputmargin;
if (rq->inplace_io) {
- src = generic_copy_inplace_data(rq, src, inputmargin);
- inputmargin = 0;
- copied = true;
+ const uint oend = (rq->pageofs_out +
+ rq->outputsize) & ~PAGE_MASK;
+ const uint nr = PAGE_ALIGN(rq->pageofs_out +
+ rq->outputsize) >> PAGE_SHIFT;
+
+ if (rq->partial_decoding || !support_0padding ||
+ rq->out[nr - 1] != rq->in[0] ||
+ rq->inputsize - oend <
+ LZ4_DECOMPRESS_INPLACE_MARGIN(inlen)) {
+ src = generic_copy_inplace_data(rq, src, inputmargin);
+ inputmargin = 0;
+ copied = true;
+ }
}
ret = LZ4_decompress_safe_partial(src + inputmargin, out,
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index b307060dd220..25bda459f2e6 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -17,7 +17,7 @@
* incompatible with this kernel version.
*/
#define EROFS_REQUIREMENT_LZ4_0PADDING 0x00000001
-#define EROFS_ALL_REQUIREMENTS 0
+#define EROFS_ALL_REQUIREMENTS EROFS_REQUIREMENT_LZ4_0PADDING
struct erofs_super_block {
/* 0 */__le32 magic; /* in the little endian */
--
2.17.1
next prev parent reply other threads:[~2019-08-02 12:53 UTC|newest]
Thread overview: 159+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-02 12:53 [PATCH v6 00/24] erofs: promote erofs from staging Gao Xiang
2019-08-02 12:53 ` [PATCH v6 01/24] erofs: add on-disk layout Gao Xiang
2019-08-29 9:59 ` Christoph Hellwig
2019-08-29 10:32 ` Gao Xiang
2019-08-29 10:36 ` Christoph Hellwig
2019-08-29 10:58 ` Gao Xiang
2019-08-29 15:58 ` Joe Perches
2019-08-29 17:26 ` Gao Xiang
2019-08-30 12:07 ` David Sterba
2019-08-30 12:18 ` Gao Xiang via Linux-erofs
2019-09-02 8:43 ` Pavel Machek
2019-09-02 14:07 ` David Sterba
2019-09-03 11:27 ` Pavel Machek
2019-08-29 15:41 ` Gao Xiang
2019-09-01 7:54 ` Gao Xiang via Linux-erofs
2019-09-02 12:45 ` Christoph Hellwig
2019-09-02 13:02 ` Gao Xiang
2019-09-02 8:40 ` Pavel Machek
2019-09-02 10:35 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 02/24] erofs: add erofs in-memory stuffs Gao Xiang
2019-08-02 12:53 ` [PATCH v6 03/24] erofs: add super block operations Gao Xiang
2019-08-29 10:15 ` Christoph Hellwig
2019-08-29 10:50 ` Gao Xiang
2019-08-30 16:39 ` Christoph Hellwig
2019-08-30 17:15 ` Gao Xiang
2019-08-31 0:54 ` Gao Xiang
2019-08-31 6:34 ` Amir Goldstein
2019-08-31 6:48 ` Gao Xiang
2019-09-01 8:54 ` Gao Xiang via Linux-erofs
2019-09-02 12:51 ` Christoph Hellwig
2019-09-02 14:43 ` Gao Xiang
2019-09-02 15:19 ` Christoph Hellwig
2019-09-02 15:24 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 04/24] erofs: add raw address_space operations Gao Xiang
2019-08-29 10:17 ` Christoph Hellwig
2019-08-29 11:46 ` Gao Xiang
2019-08-30 16:40 ` Christoph Hellwig
2019-08-30 17:23 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 05/24] erofs: add inode operations Gao Xiang
2019-08-29 10:24 ` Christoph Hellwig
2019-08-29 11:59 ` Gao Xiang
2019-08-30 16:42 ` Christoph Hellwig
2019-08-30 18:46 ` Gao Xiang
2019-09-01 9:34 ` Gao Xiang via Linux-erofs
2019-09-02 12:53 ` Christoph Hellwig
2019-09-02 13:43 ` David Sterba
2019-09-02 13:55 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 06/24] erofs: support special inode Gao Xiang
2019-08-29 10:25 ` Christoph Hellwig
2019-09-01 9:39 ` Gao Xiang via Linux-erofs
2019-08-02 12:53 ` [PATCH v6 07/24] erofs: add directory operations Gao Xiang
2019-08-02 12:53 ` [PATCH v6 08/24] erofs: add namei functions Gao Xiang
2019-08-29 10:28 ` Christoph Hellwig
2019-08-29 11:28 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 09/24] erofs: support tracepoint Gao Xiang
2019-08-02 12:53 ` [PATCH v6 10/24] erofs: update Kconfig and Makefile Gao Xiang
2019-08-02 12:53 ` [PATCH v6 11/24] erofs: introduce xattr & posixacl support Gao Xiang
2019-08-02 12:53 ` [PATCH v6 12/24] erofs: introduce tagged pointer Gao Xiang
2019-08-02 12:53 ` [PATCH v6 13/24] erofs: add compression indexes support Gao Xiang
2019-08-02 12:53 ` [PATCH v6 14/24] erofs: introduce superblock registration Gao Xiang
2019-08-02 12:53 ` [PATCH v6 15/24] erofs: introduce erofs shrinker Gao Xiang
2019-08-02 12:53 ` [PATCH v6 16/24] erofs: introduce workstation for decompression Gao Xiang
2019-08-02 12:53 ` [PATCH v6 17/24] erofs: introduce per-CPU buffers implementation Gao Xiang
2019-08-02 12:53 ` [PATCH v6 18/24] erofs: introduce pagevec for decompression subsystem Gao Xiang
2019-08-02 12:53 ` [PATCH v6 19/24] erofs: add erofs_allocpage() Gao Xiang
2019-08-02 12:53 ` [PATCH v6 20/24] erofs: introduce generic decompression backend Gao Xiang
2019-08-02 12:53 ` Gao Xiang [this message]
2019-08-02 12:53 ` [PATCH v6 22/24] erofs: introduce the decompression frontend Gao Xiang
2019-08-02 12:53 ` [PATCH v6 23/24] erofs: introduce cached decompression Gao Xiang
2019-08-02 12:53 ` [PATCH v6 24/24] erofs: add document Gao Xiang
2019-09-01 5:51 ` [PATCH 00/21] erofs: patchset addressing Christoph's comments Gao Xiang via Linux-erofs
2019-09-01 5:51 ` [PATCH 01/21] erofs: remove all the byte offset comments Gao Xiang via Linux-erofs
2019-09-02 12:05 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 02/21] erofs: on-disk format should have explicitly assigned numbers Gao Xiang via Linux-erofs
2019-09-02 12:05 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 03/21] erofs: some macros are much more readable as a function Gao Xiang via Linux-erofs
2019-09-02 12:06 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 04/21] erofs: kill __packed for on-disk structures Gao Xiang via Linux-erofs
2019-09-02 12:06 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 05/21] erofs: update erofs_inode_is_data_compressed helper Gao Xiang via Linux-erofs
2019-09-02 12:07 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 06/21] erofs: kill erofs_{init,exit}_inode_cache Gao Xiang via Linux-erofs
2019-09-02 12:09 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 07/21] erofs: use erofs_inode naming Gao Xiang via Linux-erofs
2019-09-02 12:10 ` Christoph Hellwig
2019-09-02 12:13 ` Gao Xiang
2019-09-02 12:47 ` Christoph Hellwig
2019-09-02 13:33 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 08/21] erofs: update comments in inode.c Gao Xiang via Linux-erofs
2019-09-01 5:51 ` [PATCH 09/21] erofs: update erofs symlink stuffs Gao Xiang via Linux-erofs
2019-09-02 12:11 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 10/21] erofs: kill is_inode_layout_compression() Gao Xiang via Linux-erofs
2019-09-02 12:11 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 11/21] erofs: use dsb instead of layout for ondisk super_block Gao Xiang via Linux-erofs
2019-09-02 12:12 ` Christoph Hellwig
2019-09-02 12:15 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 12/21] erofs: kill verbose debug info in erofs_fill_super Gao Xiang via Linux-erofs
2019-09-02 12:14 ` Christoph Hellwig
2019-09-02 12:18 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 13/21] erofs: simplify erofs_grab_bio() since bio_alloc() never fail Gao Xiang via Linux-erofs
2019-09-02 12:20 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 14/21] erofs: kill prio and nofail of erofs_get_meta_page() Gao Xiang via Linux-erofs
2019-09-02 12:21 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 15/21] erofs: kill __submit_bio() Gao Xiang via Linux-erofs
2019-09-01 5:51 ` [PATCH 16/21] erofs: kill magic underscores Gao Xiang via Linux-erofs
2019-09-02 12:26 ` Christoph Hellwig
2019-09-02 12:39 ` Gao Xiang
2019-09-02 12:54 ` Christoph Hellwig
2019-09-02 13:38 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 17/21] erofs: use a switch statement when dealing with the file modes Gao Xiang via Linux-erofs
2019-09-02 12:27 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 18/21] erofs: add "erofs_" prefix for common and short functions Gao Xiang via Linux-erofs
2019-09-02 12:28 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 19/21] erofs: kill all erofs specific fault injection Gao Xiang via Linux-erofs
2019-09-02 12:28 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 20/21] erofs: kill use_vmap module parameter Gao Xiang via Linux-erofs
2019-09-02 12:31 ` Christoph Hellwig
2019-09-02 12:43 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 21/21] erofs: save one level of indentation Gao Xiang via Linux-erofs
2019-09-02 12:31 ` Christoph Hellwig
2019-09-02 12:46 ` [PATCH 00/21] erofs: patchset addressing Christoph's comments Christoph Hellwig
2019-09-02 14:24 ` Gao Xiang
2019-09-02 15:23 ` Christoph Hellwig
2019-09-02 15:50 ` Gao Xiang
2019-09-03 6:58 ` Christoph Hellwig
2019-09-03 8:17 ` Gao Xiang
2019-09-03 15:37 ` Christoph Hellwig
2019-09-03 15:43 ` Gao Xiang via Linux-erofs
2019-09-04 2:08 ` [PATCH v2 00/25] " Gao Xiang
2019-09-04 2:08 ` [PATCH v2 01/25] erofs: remove all the byte offset comments Gao Xiang
2019-09-04 2:08 ` [PATCH v2 02/25] erofs: on-disk format should have explicitly assigned numbers Gao Xiang
2019-09-04 2:08 ` [PATCH v2 03/25] erofs: some macros are much more readable as a function Gao Xiang
2019-09-04 2:08 ` [PATCH v2 04/25] erofs: kill __packed for on-disk structures Gao Xiang
2019-09-04 2:08 ` [PATCH v2 05/25] erofs: update erofs_inode_is_data_compressed helper Gao Xiang
2019-09-04 2:08 ` [PATCH v2 06/25] erofs: use feature_incompat rather than requirements Gao Xiang
2019-09-04 2:08 ` [PATCH v2 07/25] erofs: better naming for erofs inode related stuffs Gao Xiang
2019-09-04 2:08 ` [PATCH v2 08/25] erofs: kill erofs_{init,exit}_inode_cache Gao Xiang
2019-09-04 2:08 ` [PATCH v2 09/25] erofs: use erofs_inode naming Gao Xiang
2019-09-04 2:08 ` [PATCH v2 10/25] erofs: update erofs_fs.h comments Gao Xiang
2019-09-04 2:08 ` [PATCH v2 11/25] erofs: update comments in inode.c Gao Xiang
2019-09-04 2:08 ` [PATCH v2 12/25] erofs: better erofs symlink stuffs Gao Xiang
2019-09-04 2:09 ` [PATCH v2 13/25] erofs: use dsb instead of layout for ondisk super_block Gao Xiang
2019-09-04 2:09 ` [PATCH v2 14/25] erofs: kill verbose debug info in erofs_fill_super Gao Xiang
2019-09-04 2:09 ` [PATCH v2 15/25] erofs: localize erofs_grab_bio() Gao Xiang
2019-09-04 2:09 ` [PATCH v2 16/25] erofs: kill prio and nofail of erofs_get_meta_page() Gao Xiang
2019-09-04 2:09 ` [PATCH v2 17/25] erofs: kill __submit_bio() Gao Xiang
2019-09-04 2:09 ` [PATCH v2 18/25] erofs: add "erofs_" prefix for common and short functions Gao Xiang
2019-09-04 2:09 ` [PATCH v2 19/25] erofs: kill all erofs specific fault injection Gao Xiang
2019-09-04 2:09 ` [PATCH v2 20/25] erofs: kill use_vmap module parameter Gao Xiang
2019-09-04 2:09 ` [PATCH v2 21/25] erofs: save one level of indentation Gao Xiang
2019-09-04 2:09 ` [PATCH v2 22/25] erofs: rename errln/infoln/debugln to erofs_{err, info, dbg} Gao Xiang
2019-09-04 2:09 ` [PATCH v2 23/25] erofs: use read_mapping_page instead of sb_bread Gao Xiang
2019-09-04 2:09 ` [PATCH v2 24/25] erofs: always use iget5_locked Gao Xiang
2019-09-04 2:09 ` [PATCH v2 25/25] erofs: use read_cache_page_gfp for erofs_get_meta_page Gao Xiang
2019-09-04 3:27 ` [PATCH v2 00/25] erofs: patchset addressing Christoph's comments Chao Yu
2019-09-05 1:03 ` Gao Xiang via Linux-erofs
2019-09-05 11:30 ` Christoph Hellwig
2019-09-04 5:16 ` Christoph Hellwig
2019-09-04 6:08 ` Gao Xiang via Linux-erofs
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