squashfs: allows users to configure the number of decompression threads

The maximum number of threads in the decompressor_multi.c file is fixed
and cannot be adjusted according to user needs. There

squashfs: allows users to configure the number of decompression threads

The maximum number of threads in the decompressor_multi.c file is fixed
and cannot be adjusted according to user needs. Therefore, the mount
parameter needs to be added to allow users to configure the number of
threads as required. The upper limit is num_online_cpus() * 2.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Xiaoming Ni <[email protected]>
Reviewed-by: Phillip Lougher <[email protected]>
Cc: Jianguo Chen <[email protected]>
Cc: Jubin Zhong <[email protected]>
Cc: Zhang Yi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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squashfs: add the mount parameter theads=<single|multi|percpu>

Patch series 'squashfs: Add the mount parameter "threads="'.

Currently, Squashfs supports multiple decompressor parallel modes.
Howev

squashfs: add the mount parameter theads=<single|multi|percpu>

Patch series 'squashfs: Add the mount parameter "threads="'.

Currently, Squashfs supports multiple decompressor parallel modes.
However, this mode can be configured only during kernel building and does
not support flexible selection during runtime.

In the current patch set, the mount parameter "threads=" is added to allow
users to select the parallel decompressor mode and configure the number of
decompressors when mounting a file system.

"threads=<single|multi|percpu|1|2|3|...>"
The upper limit is num_online_cpus() * 2.


This patch (of 2):

Squashfs supports three decompression concurrency modes:
Single-thread mode: concurrent reads are blocked and the memory
overhead is small.
Multi-thread mode/percpu mode: reduces concurrent read blocking but
increases memory overhead.

The corresponding schema must be fixed at compile time. During mounting,
the concurrent decompression mode cannot be adjusted based on file read
blocking.

The mount parameter theads=<single|multi|percpu> is added to select
the concurrent decompression mode of a single SquashFS file system
image.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Xiaoming Ni <[email protected]>
Reviewed-by: Phillip Lougher <[email protected]>
Cc: Jianguo Chen <[email protected]>
Cc: Jubin Zhong <[email protected]>
Cc: Zhang Yi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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squashfs: migrate from ll_rw_block usage to BIO

ll_rw_block() function has been deprecated in favor of BIO which appears
to come with large performance improvements.

This patch decreases boot time

squashfs: migrate from ll_rw_block usage to BIO

ll_rw_block() function has been deprecated in favor of BIO which appears
to come with large performance improvements.

This patch decreases boot time by close to 40% when using squashfs for
the root file-system. This is observed at least in the context of
starting an Android VM on Chrome OS using crosvm. The patch was tested
on 4.19 as well as master.

This patch is largely based on Adrien Schildknecht's patch that was
originally sent as https://lkml.org/lkml/2017/9/22/814 though with some
significant changes and simplifications while also taking Phillip
Lougher's feedback into account, around preserving support for
FILE_CACHE in particular.

[[email protected]: fix build error reported by Randy]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Philippe Liard <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Adrien Schildknecht <[email protected]>
Cc: Phillip Lougher <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Daniel Rosenberg <[email protected]>
Link: https://chromium.googlesource.com/chromiumos/platform/crosvm
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499

Based on 1 normalized pattern(s):

this work is licensed under the terms of the gnu gpl version 2 see
the copying file in the t

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499

Based on 1 normalized pattern(s):

this work is licensed under the terms of the gnu gpl version 2 see
the copying file in the top level directory

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 35 file(s).

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Enrico Weigelt <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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Squashfs: Check stream is not NULL in decompressor_multi.c

Fix static checker complaint that stream is not checked in
squashfs_decompressor_destroy().

Reported-by: Dan Carpenter <dan.carpenter@orac

Squashfs: Check stream is not NULL in decompressor_multi.c

Fix static checker complaint that stream is not checked in
squashfs_decompressor_destroy().

Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Phillip Lougher <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>

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Squashfs: Generalise paging handling in the decompressors

Further generalise the decompressors by adding a page handler
abstraction. This adds helpers to allow the decompressors
to access and proce

Squashfs: Generalise paging handling in the decompressors

Further generalise the decompressors by adding a page handler
abstraction. This adds helpers to allow the decompressors
to access and process the output buffers in an implementation
independant manner.

This allows different types of output buffer to be passed
to the decompressors, with the implementation specific
aspects handled at decompression time, but without the
knowledge being held in the decompressor wrapper code.

This will allow the decompressors to handle Squashfs
cache buffers, and page cache pages.

This patch adds the abstraction and an implementation for
the caches.

Signed-off-by: Phillip Lougher <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>

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squashfs: Enhance parallel I/O

Now squashfs have used for only one stream buffer for decompression
so it hurts parallel read performance so this patch supports
multiple decompressor to enhance perfo

squashfs: Enhance parallel I/O

Now squashfs have used for only one stream buffer for decompression
so it hurts parallel read performance so this patch supports
multiple decompressor to enhance performance parallel I/O.

Four 1G file dd read on KVM machine which has 2 CPU and 4G memory.

dd if=test/test1.dat of=/dev/null &
dd if=test/test2.dat of=/dev/null &
dd if=test/test3.dat of=/dev/null &
dd if=test/test4.dat of=/dev/null &

old : 1m39s -> new : 9s

* From v1
* Change comp_strm with decomp_strm - Phillip
* Change/add comments - Phillip

Signed-off-by: Minchan Kim <[email protected]>
Signed-off-by: Phillip Lougher <[email protected]>

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