zram: ZRAM_DEF_COMP should depend on ZRAM

When Compressed RAM block device support is disabled, the
CONFIG_ZRAM_DEF_COMP symbol still ends up in the generated config file:

CONFIG_ZRAM_DEF_COMP=

zram: ZRAM_DEF_COMP should depend on ZRAM

When Compressed RAM block device support is disabled, the
CONFIG_ZRAM_DEF_COMP symbol still ends up in the generated config file:

CONFIG_ZRAM_DEF_COMP="unset-value"

While this causes no real harm, avoid polluting the config file by
adding a dependency on ZRAM.

Link: https://lkml.kernel.org/r/64e05bad68a9bd5cc322efd114a04d25de525940.1730807319.git.geert@linux-m68k.org
Fixes: 917a59e81c34 ("zram: introduce custom comp backends API")
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: check that backends array has at least one backend

Make sure that backends array has anything apart from the sentinel NULL
value.

We also select LZO_BACKEND if none backends were selected.

L

zram: check that backends array has at least one backend

Make sure that backends array has anything apart from the sentinel NULL
value.

We also select LZO_BACKEND if none backends were selected.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: add 842 compression backend support

Add s/w 842 compression support.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <seno

zram: add 842 compression backend support

Add s/w 842 compression support.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: add zlib compression backend support

Add s/w zlib (inflate/deflate) compression.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senoz

zram: add zlib compression backend support

Add s/w zlib (inflate/deflate) compression.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: add zstd compression backend support

Add s/w zstd compression.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <senozhatsky

zram: add zstd compression backend support

Add s/w zstd compression.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: add lz4hc compression backend support

Add s/w lz4hc compression support.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <s

zram: add lz4hc compression backend support

Add s/w lz4hc compression support.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: add lz4 compression backend support

Add s/w lz4 compression support.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <senoz

zram: add lz4 compression backend support

Add s/w lz4 compression support.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: add lzo and lzorle compression backends support

Add s/w lzo/lzorle compression support.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey

zram: add lzo and lzorle compression backends support

Add s/w lzo/lzorle compression support.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: introduce custom comp backends API

Moving to custom backends implementation gives us ability to have our own
minimalistic and extendable API, and algorithms tunings becomes possible.

The list

zram: introduce custom comp backends API

Moving to custom backends implementation gives us ability to have our own
minimalistic and extendable API, and algorithms tunings becomes possible.

The list of compression backends is empty at this point, we will add
backends in the followup patches.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nick Terrell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zsmalloc: use all available 24 bits of page_type

Now that we have an extra 8 bits, we don't need to limit ourselves to
supporting a 64KiB page size. I'm sure both Hexagon users are grateful,
but it

zsmalloc: use all available 24 bits of page_type

Now that we have an extra 8 bits, we don't need to limit ourselves to
supporting a 64KiB page size. I'm sure both Hexagon users are grateful,
but it does reduce complexity a little. We can also remove
reset_first_obj_offset() as calling __ClearPageZsmalloc() will now reset
all 32 bits of page_type.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Hyeonggon Yoo <[email protected]>
Cc: Kent Overstreet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm/zsmalloc: use a proper page type

Let's clean it up: use a proper page type and store our data (offset into
a page) in the lower 16 bit as documented.

We won't be able to support 256 KiB base pag

mm/zsmalloc: use a proper page type

Let's clean it up: use a proper page type and store our data (offset into
a page) in the lower 16 bit as documented.

We won't be able to support 256 KiB base pages, which is acceptable.
Teach Kconfig to handle that cleanly using a new CONFIG_HAVE_ZSMALLOC.

Based on this, we should do a proper "struct zsdesc" conversion, as
proposed in [1].

This removes the last _mapcount/page_type offender.

[1] https://lore.kernel.org/all/[email protected]/

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Tested-by: Sergey Senozhatsky <[email protected]> [zram/zsmalloc workloads]
Reviewed-by: Sergey Senozhatsky <[email protected]>
Cc: Hyeonggon Yoo <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: tweak writeback config help

Writeback is for incompressible and idle zram pages.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozh

zram: tweak writeback config help

Writeback is for incompressible and idle zram pages.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Dmytro Maluka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: split memory-tracking and ac-time tracking

ZRAM_MEMORY_TRACKING enables two features:
- per-entry ac-time tracking
- debugfs interface

The latter one is the reason why memory-tracking depends

zram: split memory-tracking and ac-time tracking

ZRAM_MEMORY_TRACKING enables two features:
- per-entry ac-time tracking
- debugfs interface

The latter one is the reason why memory-tracking depends on DEBUG_FS,
while the former one is used far beyond debugging these days. Namely
ac-time is used for fine grained writeback of idle entries (pages).

Move ac-time tracking under its own config option so that it can be
enabled (along with writeback) on systems without DEBUG_FS.

[[email protected]: ifdef fixup, per Dmytro]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Dmytro Maluka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: introduce recompress sysfs knob

Allow zram to recompress (using secondary compression streams)
pages.

Re-compression algorithms (we support up to 3 at this stage)
are selected via recomp_algo

zram: introduce recompress sysfs knob

Allow zram to recompress (using secondary compression streams)
pages.

Re-compression algorithms (we support up to 3 at this stage)
are selected via recomp_algorithm:

echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm

Please read documentation for more details.

We support several recompression modes:

1) IDLE pages recompression is activated by `idle` mode

echo "type=idle" > /sys/block/zram0/recompress

2) Since there may be many idle pages user-space may pass a size
threshold value (in bytes) and we will recompress pages only
of equal or greater size:

echo "threshold=888" > /sys/block/zram0/recompress

3) HUGE pages recompression is activated by `huge` mode

echo "type=huge" > /sys/block/zram0/recompress

4) HUGE_IDLE pages recompression is activated by `huge_idle` mode

echo "type=huge_idle" > /sys/block/zram0/recompress

[[email protected]: we should always zero out err variable in recompress loop[
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Alexey Romanov <[email protected]>
Cc: Nhat Pham <[email protected]>
Cc: Nitin Gupta <[email protected]>
Cc: Suleiman Souhlal <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: fix Kconfig dependency warning

ZSMALLOC depends on MMU so ZRAM should also depend on MMU since 'select'
does not follow any dependency chains.

Fixes this Kconfig warning:

WARNING: unmet dire

zram: fix Kconfig dependency warning

ZSMALLOC depends on MMU so ZRAM should also depend on MMU since 'select'
does not follow any dependency chains.

Fixes this Kconfig warning:

WARNING: unmet direct dependencies detected for ZSMALLOC
Depends on [n]: MMU [=n]
Selected by [y]:
- ZRAM [=y] && BLK_DEV [=y] && BLOCK [=y] && SYSFS [=y] && (CRYPTO_LZO [=y] || CRYPTO_ZSTD [=m] || CRYPTO_LZ4 [=m] || CRYPTO_LZ4HC [=n] || CRYPTO_842 [=n])

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b3fbd58fcbb10 ("mm: Kconfig: simplify zswap configuration")
Signed-off-by: Randy Dunlap <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Nitin Gupta <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Jens Axboe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

mm: Kconfig: simplify zswap configuration

- CONFIG_ZRAM: Zram is a user-facing feature, whereas zsmalloc is
not. Don't make the user chase down a technical dependency like
that, just select it i

mm: Kconfig: simplify zswap configuration

- CONFIG_ZRAM: Zram is a user-facing feature, whereas zsmalloc is
not. Don't make the user chase down a technical dependency like
that, just select it in automatically when zram is requested. The
CONFIG_CRYPTO dependency is redundant due to more specific deps.

- CONFIG_ZPOOL: This is not a user-facing feature. Hide the symbol and
have it selected in as needed.

- CONFIG_ZSWAP: Select CRYPTO instead of depend. Common pattern.

- Make the ZSWAP suboptions and their descriptions (compression,
allocation backend) a bit more straight-forward for the user.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Johannes Weiner <[email protected]>
Cc: Dan Streetman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Seth Jennings <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

zram: break the strict dependency from lzo

From the beginning, the zram block device always enabled CRYPTO_LZO,
since lzo-rle is hardcoded as the fallback compression algorithm. As a
consequence, o

zram: break the strict dependency from lzo

From the beginning, the zram block device always enabled CRYPTO_LZO,
since lzo-rle is hardcoded as the fallback compression algorithm. As a
consequence, on systems where another compression algorithm is chosen
(e.g. CRYPTO_ZSTD), the lzo kernel module becomes unused, while still
having to be built/loaded.

This patch removes the hardcoded lzo-rle dependency and allows the user
to select the default compression algorithm for zram at build time. The
previous behaviour is kept, as the default algorithm is still lzo-rle.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Rui Salvaterra <[email protected]>
Suggested-by: Sergey Senozhatsky <[email protected]>
Suggested-by: Minchan Kim <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

docs: blockdev: add it to the admin-guide

The blockdev book basically contains user-faced documentation.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>

docs: blockdev: convert to ReST

Rename the blockdev documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

The drbd sub-di

docs: blockdev: convert to ReST

Rename the blockdev documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

The drbd sub-directory contains some graphs and data flows.
Add those too to the documentation.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>

show more ...

zram: support idle/huge page writeback

Add a new feature "zram idle/huge page writeback". In the zram-swap use
case, zram usually has many idle/huge swap pages. It's pointless to keep
them in memo

zram: support idle/huge page writeback

Add a new feature "zram idle/huge page writeback". In the zram-swap use
case, zram usually has many idle/huge swap pages. It's pointless to keep
them in memory (ie, zram).

To solve this problem, this feature introduces idle/huge page writeback to
the backing device so the goal is to save more memory space on embedded
systems.

Normal sequence to use idle/huge page writeback feature is as follows,

while (1) {
# mark allocated zram slot to idle
echo all > /sys/block/zram0/idle
# leave system working for several hours
# Unless there is no access for some blocks on zram,
# they are still IDLE marked pages.

echo "idle" > /sys/block/zram0/writeback
or/and
echo "huge" > /sys/block/zram0/writeback
# write the IDLE or/and huge marked slot into backing device
# and free the memory.
}

Per the discussion at
https://lore.kernel.org/lkml/20181122065926.GG3441@jagdpanzerIV/T/#u,

This patch removes direct incommpressibe page writeback feature
(d2afd25114f4 ("zram: write incompressible pages to backing device")).

Below concerns from Sergey:
== &< ==

"IDLE writeback" is superior to "incompressible writeback".

"incompressible writeback" is completely unpredictable and uncontrollable;
it depens on data patterns and compression algorithms. While "IDLE
writeback" is predictable.

I even suspect, that, *ideally*, we can remove "incompressible writeback".
"IDLE pages" is a super set which also includes "incompressible" pages.
So, technically, we still can do "incompressible writeback" from "IDLE
writeback" path; but a much more reasonable one, based on a page idling
period.

I understand that you want to keep "direct incompressible writeback"
around. ZRAM is especially popular on devices which do suffer from flash
wearout, so I can see "incompressible writeback" path becoming a dead
code, long term.

== &< ==

Below concerns from Minchan:
== &< ==

My concern is if we enable CONFIG_ZRAM_WRITEBACK in this implementation,
both hugepage/idlepage writeck will turn on. However someuser want to
enable only idlepage writeback so we need to introduce turn on/off knob
for hugepage or new CONFIG_ZRAM_IDLEPAGE_WRITEBACK for those usecase. I
don't want to make it complicated *if possible*.

Long term, I imagine we need to make VM aware of new swap hierarchy a
little bit different with as-is. For example, first high priority swap
can return -EIO or -ENOCOMP, swap try to fallback to next lower priority
swap device. With that, hugepage writeback will work tranparently.

So we could regard it as regression because incompressible pages doesn't
go to backing storage automatically. Instead, user should do it via "echo
huge" > /sys/block/zram/writeback" manually.

== &< ==

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Reviewed-by: Joey Pabalinas <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

drivers/block: remove redundant 'default n' from Kconfig-s

'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.

Also since commit f4

drivers/block: remove redundant 'default n' from Kconfig-s

'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.

Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:

...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:

config FOO
bool

config FOO
bool
default n

With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...

Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

show more ...

zram: introduce zram memory tracking

zRam as swap is useful for small memory device. However, swap means
those pages on zram are mostly cold pages due to VM's LRU algorithm.
Especially, once init d

zram: introduce zram memory tracking

zRam as swap is useful for small memory device. However, swap means
those pages on zram are mostly cold pages due to VM's LRU algorithm.
Especially, once init data for application are touched for launching,
they tend to be not accessed any more and finally swapped out. zRAM can
store such cold pages as compressed form but it's pointless to keep in
memory. Better idea is app developers free them directly rather than
remaining them on heap.

This patch tell us last access time of each block of zram via "cat
/sys/kernel/debug/zram/zram0/block_state".

The output is as follows,
300 75.033841 .wh
301 63.806904 s..
302 63.806919 ..h

First column is zram's block index and 3rh one represents symbol (s:
same page w: written page to backing store h: huge page) of the block
state. Second column represents usec time unit of the block was last
accessed. So above example means the 300th block is accessed at
75.033851 second and it was huge so it was written to the backing store.

Admin can leverage this information to catch cold|incompressible pages
of process with *pagemap* once part of heaps are swapped out.

I used the feature a few years ago to find memory hoggers in userspace
to notify them what memory they have wasted without touch for a long
time. With it, they could reduce unnecessary memory space. However, at
that time, I hacked up zram for the feature but now I need the feature
again so I decided it would be better to upstream rather than keeping it
alone. I hope I submit the userspace tool to use the feature soon.

[[email protected]: fix i386 printk warning]
[[email protected]: use ktime_get_boottime() instead of sched_clock()]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: documentation tweak]
[[email protected]: fix i386 printk warning]
[[email protected]: fix compile warning]
Link: http://lkml.kernel.org/r/[email protected]
[[email protected]: fix printk formats]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Signed-off-by: Randy Dunlap <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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zram: add config and doc file for writeback feature

This patch adds document and kconfig for using of writeback feature.

Link: http://lkml.kernel.org/r/1498459987-24562-10-git-send-email-minchan@ke

zram: add config and doc file for writeback feature

This patch adds document and kconfig for using of writeback feature.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Cc: Juneho Choi <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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zram: delete custom lzo/lz4

Remove lzo/lz4 backends, we use crypto API now.

[[email protected]: zram-delete-custom-lzo-lz4-v3]
Link: http://lkml.kernel.org/r/20160604024902.11778-6-ser

zram: delete custom lzo/lz4

Remove lzo/lz4 backends, we use crypto API now.

[[email protected]: zram-delete-custom-lzo-lz4-v3]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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