History log of /linux-master/lib/zlib_deflate/deflate.c
Revision Date Author Comments
# 9fec9f8e 26-Jan-2023 Mikhail Zaslonko <zaslonko@linux.ibm.com>

lib/zlib: Split deflate and inflate states for DFLTCC

Currently deflate and inflate both use a common state struct. There are
several variables in this struct that we don't need for inflate, and
more may be coming in the future. Therefore split them in two separate
structs.
Apart from that, introduce separate headers for dfltcc_deflate and
dfltcc_inflate.

This commit is based on:
https://github.com/zlib-ng/zlib-ng/commit/c592b1b

Link: https://lkml.kernel.org/r/20230126131428.1222214-7-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>


# 195c5ad9 26-Jan-2023 Mikhail Zaslonko <zaslonko@linux.ibm.com>

lib/zlib: fix DFLTCC not flushing EOBS when creating raw streams

This commit is based on:
https://github.com/zlib-ng/zlib-ng/commit/ca99a88

Link: https://lkml.kernel.org/r/20230126131428.1222214-4-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>


# 803521b1 30-Jan-2020 Mikhail Zaslonko <zaslonko@linux.ibm.com>

lib/zlib: add zlib_deflate_dfltcc_enabled() function

Add a new function to zlib.h checking if s390 Deflate-Conversion
facility is installed and enabled.

Link: http://lkml.kernel.org/r/20200103223334.20669-6-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# aa5b395b 30-Jan-2020 Mikhail Zaslonko <zaslonko@linux.ibm.com>

lib/zlib: add s390 hardware support for kernel zlib_deflate

Patch series "S390 hardware support for kernel zlib", v3.

With IBM z15 mainframe the new DFLTCC instruction is available. It
implements deflate algorithm in hardware (Nest Acceleration Unit - NXU)
with estimated compression and decompression performance orders of
magnitude faster than the current zlib.

This patchset adds s390 hardware compression support to kernel zlib.
The code is based on the userspace zlib implementation:

https://github.com/madler/zlib/pull/410

The coding style is also preserved for future maintainability. There is
only limited set of userspace zlib functions represented in kernel.
Apart from that, all the memory allocation should be performed in
advance. Thus, the workarea structures are extended with the parameter
lists required for the DEFLATE CONVENTION CALL instruction.

Since kernel zlib itself does not support gzip headers, only Adler-32
checksum is processed (also can be produced by DFLTCC facility). Like
it was implemented for userspace, kernel zlib will compress in hardware
on level 1, and in software on all other levels. Decompression will
always happen in hardware (when enabled).

Two DFLTCC compression calls produce the same results only when they
both are made on machines of the same generation, and when the
respective buffers have the same offset relative to the start of the
page. Therefore care should be taken when using hardware compression
when reproducible results are desired. However it does always produce
the standard conform output which can be inflated anyway.

The new kernel command line parameter 'dfltcc' is introduced to
configure s390 zlib hardware support:

Format: { on | off | def_only | inf_only | always }
on: s390 zlib hardware support for compression on
level 1 and decompression (default)
off: No s390 zlib hardware support
def_only: s390 zlib hardware support for deflate
only (compression on level 1)
inf_only: s390 zlib hardware support for inflate
only (decompression)
always: Same as 'on' but ignores the selected compression
level always using hardware support (used for debugging)

The main purpose of the integration of the NXU support into the kernel
zlib is the use of hardware deflate in btrfs filesystem with on-the-fly
compression enabled. Apart from that, hardware support can also be used
during boot for decompressing the kernel or the ramdisk image

With the patch for btrfs expanding zlib buffer from 1 to 4 pages (patch
6) the following performance results have been achieved using the
ramdisk with btrfs. These are relative numbers based on throughput rate
and compression ratio for zlib level 1:

Input data Deflate rate Inflate rate Compression ratio
NXU/Software NXU/Software NXU/Software
stream of zeroes 1.46 1.02 1.00
random ASCII data 10.44 3.00 0.96
ASCII text (dickens) 6,21 3.33 0.94
binary data (vmlinux) 8,37 3.90 1.02

This means that s390 hardware deflate can provide up to 10 times faster
compression (on level 1) and up to 4 times faster decompression (refers
to all compression levels) for btrfs zlib.

Disclaimer: Performance results are based on IBM internal tests using DD
command-line utility on btrfs on a Fedora 30 based internal driver in
native LPAR on a z15 system. Results may vary based on individual
workload, configuration and software levels.

This patch (of 9):

Create zlib_dfltcc library with the s390 DEFLATE CONVERSION CALL
implementation and related compression functions. Update zlib_deflate
functions with the hooks for s390 hardware support and adjust workspace
structures with extra parameter lists required for hardware deflate.

Link: http://lkml.kernel.org/r/20200103223334.20669-2-zaslonko@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Co-developed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 62e7ca52 06-Aug-2014 Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

zlib: clean up some dead code

Cleanup unused `if 0'-ed functions, which have been dead since 2006
(commits 87c2ce3b9305 ("lib/zlib*: cleanups") by Adrian Bunk and
4f3865fb57a0 ("zlib_inflate: Upgrade library code to a recent version")
by Richard Purdie):

- zlib_deflateSetDictionary
- zlib_deflateParams
- zlib_deflateCopy
- zlib_inflateSync
- zlib_syncsearch
- zlib_inflateSetDictionary
- zlib_inflatePrime

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 565d76cb 22-Mar-2011 Jim Keniston <jkenisto@linux.vnet.ibm.com>

zlib: slim down zlib_deflate() workspace when possible

Instead of always creating a huge (268K) deflate_workspace with the
maximum compression parameters (windowBits=15, memLevel=8), allow the
caller to obtain a smaller workspace by specifying smaller parameter
values.

For example, when capturing oops and panic reports to a medium with
limited capacity, such as NVRAM, compression may be the only way to
capture the whole report. In this case, a small workspace (24K works
fine) is a win, whether you allocate the workspace when you need it (i.e.,
during an oops or panic) or at boot time.

I've verified that this patch works with all accepted values of windowBits
(positive and negative), memLevel, and compression level.

Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# fd589a8f 16-Jul-2009 Anand Gadiyar <gadiyar@ti.com>

trivial: fix typo "to to" in multiple files

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>


# 4f3865fb 22-Jun-2006 Richard Purdie <rpurdie@rpsys.net>

[PATCH] zlib_inflate: Upgrade library code to a recent version

Upgrade the zlib_inflate implementation in the kernel from a patched
version 1.1.3/4 to a patched 1.2.3.

The code in the kernel is about seven years old and I noticed that the
external zlib library's inflate performance was significantly faster (~50%)
than the code in the kernel on ARM (and faster again on x86_32).

For comparison the newer deflate code is 20% slower on ARM and 50% slower
on x86_32 but gives an approx 1% compression ratio improvement. I don't
consider this to be an improvement for kernel use so have no plans to
change the zlib_deflate code.

Various changes have been made to the zlib code in the kernel, the most
significant being the extra functions/flush option used by ppp_deflate.
This update reimplements the features PPP needs to ensure it continues to
work.

This code has been tested on ARM under both JFFS2 (with zlib compression
enabled) and ppp_deflate and on x86_32. JFFS2 sees an approx. 10% real
world file read speed improvement.

This patch also removes ZLIB_VERSION as it no longer has a correct value.
We don't need version checks anyway as the kernel's module handling will
take care of that for us. This removal is also more in keeping with the
zlib author's wishes (http://www.zlib.net/zlib_faq.html#faq24) and I've
added something to the zlib.h header to note its a modified version.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Joern Engel <joern@wh.fh-wedel.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>


# 87c2ce3b 09-Jan-2006 Adrian Bunk <bunk@stusta.de>

[PATCH] lib/zlib*: cleanups

This patch contains the following possible cleanups:
- #if 0 the following unused functions:
- zlib_deflate/deflate.c: zlib_deflateSetDictionary
- zlib_deflate/deflate.c: zlib_deflateParams
- zlib_deflate/deflate.c: zlib_deflateCopy
- zlib_inflate/infblock.c: zlib_inflate_set_dictionary
- zlib_inflate/infblock.c: zlib_inflate_blocks_sync_point
- zlib_inflate/inflate_sync.c: zlib_inflateSync
- zlib_inflate/inflate_sync.c: zlib_inflateSyncPoint
- remove the following unneeded EXPORT_SYMBOL's:
- zlib_deflate/deflate_syms.c: zlib_deflateCopy
- zlib_deflate/deflate_syms.c: zlib_deflateParams
- zlib_inflate/inflate_syms.c: zlib_inflateSync
- zlib_inflate/inflate_syms.c: zlib_inflateSyncPoint

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>


# 1da177e4 16-Apr-2005 Linus Torvalds <torvalds@ppc970.osdl.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!