1ad6cc0c62
This patchset brings some performance improvements and the addition of the LZO-RLE
algorithm to the kernel, also usable in zram (yup, tested, works but LZ4 is still ok for us).
The main performance improvement is for SWAP space: the locking has changed and
the swap cache is now split in 64MB trunks.
This gives us a reduction of the median page fault latency of 375%, from 15uS to 4uS,
and an improvement of 192% on the swap throughput (this includes "virtual" swap
devices, like zRAM!). The real world user experience improvement of this on a mobile
device is seen after a day or two of usage, where it usually starts losing just a little
performance due to the large amount of apps kept open in background: now I cannot
notice any more performance loss and the user experience is now basically the same as
if the phone was in its first 2 hours of boot life.
Other performance improvements include, in short:
UDP v4/v6: 10% more performance on single RX queue
Userspace applications will be faster when checking running time of threads
2-5% improvements on heavy multipliers (yeah, not a lot, but was totally free...)
Improvements on rare conditions during sparsetruncate of about 0.3% to a
way more rare around 20% improvement (that's never gonna happen, but there
is no performance drop anywhere).
Tested on SoMC Tama Akatsuki RoW
This was taken from
Repo:
https://github.com/sonyxperiadev/kernel
PR: 2039 ([2.3.2.r1.4] Performance improvements)
50 lines
1.5 KiB
C
50 lines
1.5 KiB
C
#ifndef __LZO_H__
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#define __LZO_H__
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/*
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* LZO Public Kernel Interface
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* A mini subset of the LZO real-time data compression library
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*
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* Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com>
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*
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* The full LZO package can be found at:
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* http://www.oberhumer.com/opensource/lzo/
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*
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* Changed for Linux kernel use by:
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* Nitin Gupta <nitingupta910@gmail.com>
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* Richard Purdie <rpurdie@openedhand.com>
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*/
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#define LZO1X_1_MEM_COMPRESS (8192 * sizeof(unsigned short))
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#define LZO1X_MEM_COMPRESS LZO1X_1_MEM_COMPRESS
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#define lzo1x_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
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/* This requires 'wrkmem' of size LZO1X_1_MEM_COMPRESS */
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int lzo1x_1_compress(const unsigned char *src, size_t src_len,
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unsigned char *dst, size_t *dst_len, void *wrkmem);
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/* This requires 'wrkmem' of size LZO1X_1_MEM_COMPRESS */
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int lzorle1x_1_compress(const unsigned char *src, size_t src_len,
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unsigned char *dst, size_t *dst_len, void *wrkmem);
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/* safe decompression with overrun testing */
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int lzo1x_decompress_safe(const unsigned char *src, size_t src_len,
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unsigned char *dst, size_t *dst_len);
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/*
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* Return values (< 0 = Error)
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*/
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#define LZO_E_OK 0
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#define LZO_E_ERROR (-1)
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#define LZO_E_OUT_OF_MEMORY (-2)
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#define LZO_E_NOT_COMPRESSIBLE (-3)
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#define LZO_E_INPUT_OVERRUN (-4)
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#define LZO_E_OUTPUT_OVERRUN (-5)
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#define LZO_E_LOOKBEHIND_OVERRUN (-6)
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#define LZO_E_EOF_NOT_FOUND (-7)
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#define LZO_E_INPUT_NOT_CONSUMED (-8)
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#define LZO_E_NOT_YET_IMPLEMENTED (-9)
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#define LZO_E_INVALID_ARGUMENT (-10)
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#endif
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