Abstract: Disclosed is a compressed memory management method for a computer system having one or more processors (P1-PN), compressible main memory, secondary memory and an operating system. The compressible main memory has a compressed memory space comprising an active part directly accessible to said one or more processors (P1-PN), as well as an inactive part not directly accessible to said one or more processors (P1-PN) in the form of memory freed up by memory compression.

Abstract: A data compression method is disclosed which involves obtaining a plurality of data blocks, each data block comprising a plurality of data values. The method performs base-delta encoding of the obtained plurality of data blocks, wherein a delta value means a difference between a data value and a base value. This involves determining, among the data values of the plurality of data blocks, a set of global base values common to said plurality of data blocks. The set of global base values is selected to minimize delta values for the data values of the plurality of data blocks with respect to the global base values in said set of global base values.

Abstract: A method for accessing compressed computer memory residing in physical computer memory is disclosed. In the method, compressed memory blocks are represented as sectors, wherein all sectors contain a fixed number of compressed memory blocks, have a fixed logical size in the form of the fixed number of compressed memory blocks, and have varying physical sizes in the form of the total size of data stored in the respective compressed memory blocks.

Abstract: A decompression system has a plurality of decompression devices in an array or chain layout for decompressing respective compressed data values of a compressed data block. A first decompression device is connected to a next decompression device, and a last decompression device is connected to a preceding decompression device. The first decompression device decompresses a compressed data value and reduces the compressed data block by extracting a codeword of the compressed data value and removing the compressed data value from the compressed data block, retrieving a decompressed data value out of the extracted codeword, and passing the reduced compressed data block to the next decompression device. The last decompression device receives a reduced compressed data block from the preceding decompression device and decompresses another compressed data value by extracting a codeword of the other compressed data value, and retrieving another decompressed data value out of the extracted codeword.

Abstract: A computer memory compression method involves analyzing (1210) computer memory content with respect to occurrence of duplicate memory objects as well as value redundancy of data values in unique memory objects. The computer memory content is encoded (1220) by eliminating the duplicate memory objects and compressing each remaining unique memory object by exploiting data value locality of the data values thereof. Metadata (500) is provided (1230) to represent the memory objects of the encoded computer memory content. The metadata reflects eliminated duplicate memory objects, remaining unique memory objects as well as a type of compression used for compressing each remaining unique memory object. A memory object in the encoded computer memory content is located (1240) using the metadata (500).

Abstract: A computer memory compression method involves analyzing computer memory content with respect to occurrence of duplicate memory objects as well as value redundancy of data values in unique memory objects. The computer memory content is encoded by eliminating the duplicate memory objects and compressing each remaining unique memory object by exploiting data value locality of the data values thereof. Metadata is provided to represent the memory objects of the encoded computer memory content. The metadata reflects eliminated duplicate memory objects, remaining unique memory objects as well as a type of compression used for compressing each remaining unique memory object. A memory object in the encoded computer memory content is located using the metadata.

Abstract: A decompression system (800; 1100; 1300) for decompressing a compressed data block that comprises a plurality of compressed data values is presented. The decompression system has a plurality of decompression devices (700; 1200A-B) in an array or chain layout (820a-820m?1; 120a-1120m?1; 1320a-1320m?1) for decompressing respective compressed data values of the compressed data block. A first decompression device (820a; 1120a; 1320a) is connected to a next decompression device (820b; 1120b; 1320b), and a last decompression device (820m?1; 120m?1; 1320m?1) is connected to a preceding decompression device (820m?2; 1120m?2; 320m?2).

Abstract: Disclosed is a compressed memory management method for a computer system having one or more processors (P1-PN), compressible main memory, secondary memory and an operating system. The compressible main memory has a compressed memory space comprising an active part directly accessible to said one or more processors (P1-PN), as well as an inactive part not directly accessible to said one or more processors (P1-PN) in the form of memory freed up by memory compression.

Abstract: A method for accessing compressed computer memory residing in physical computer memory is disclosed. In the method, compressed memory blocks are represented as sectors, wherein all sectors contain a fixed number of compressed memory blocks, have a fixed logical size in the form of the fixed number of compressed memory blocks, and have varying physical sizes in the form of the total size of data stored in the respective compressed memory blocks.

Abstract: Methods, devices and systems for data compression and decompression are disclosed. A collection of data is obtained. The collection of data is sampled to establish, for a plurality of different symbol sizes, relative frequencies of symbols of the respective sizes in the collection of data. A code is generated to contain variable-length codewords by entropy encoding sampled symbols in the collection of data based on a metric which reflects the relative frequencies of the sampled symbols as well as their sizes. Symbols in the collection of data are compressed into compressed representations using the generated code, wherein the compressed representation of a symbol comprises a codeword which represents the symbol as well as metadata for decompressing the compressed representation.

Abstract: Methods, devices and systems for a compressor and a decompressor for encoding and decoding data in the cache/memory/data transferring subsystem in a computer system or in a communication network are described herein. An example variable-length compressor is able to compress blocks of data values and the compressed blocks may include mixes of compressed and uncompressed values, wherein metadata in the form of a unique special-meaning codeword (UUIC) indicates uncompressed values. An example variable-length decompressor is able to decompress the compressed data blocks. The compressor and decompressor are able to support compression and decompression of common compression scenarios that are used in combination with variable-length compression to improve compressibility in the cache/memory/data transferring subsystem in a computer system or in a communication network.

Abstract: Methods, devices and systems for a compressor and a decompressor for encoding and decoding data in the cache/memory/data transferring subsystem in a computer system or in a communication network are described herein. Example variable-length compressors and decompressors are able to: compress more densely when specific values occur in specific positions in a data block; to improve compression and decompression latency when specific values that appear frequently occur in a data block; to also improve decompression latency by recording the lengths of variable-length encoded values of a compressed data block. The compressor and decompressor are able to support compression and decompression of common compression scenarios that are used in combination with variable-length compression to improve compressibility in the cache/memory/data transferring subsystem in a computer system or in a communication network.

Abstract: Methods, devices and systems enhance compression and decompression of data blocks of data values by selecting the best suited compression method and device among two or a plurality of compression methods and devices, which are combined together and which said compression methods and devices compress effectively data values of particular data types; said best suited compression method and device is selected using as main selection criterion the dominating data type in a data block by predicting the data types within said data block.

Abstract: Methods, devices and systems for data compression and decompression are disclosed. A collection of data is obtained. The collection of data is sampled to establish, for a plurality of different symbol sizes, relative frequencies of symbols of the respective sizes in the collection of data. A code is generated to contain variable-length codewords by entropy encoding sampled symbols in the collection of data based on a metric which reflects the relative frequencies of the sampled symbols as well as their sizes. Symbols in the collection of data are compressed into compressed representations using the generated code, wherein the compressed representation of a symbol comprises a codeword which represents the symbol as well as metadata for decompressing the compressed representation.

Abstract: Methods, devices and systems enhance compression and decompression of data blocks of data values by selecting the best suited compression method and device among two or a plurality of compression methods and devices, which are combined together and which said compression methods and devices compress effectively data values of particular data types; said best suited compression method and device is selected using as main selection criterion the dominating data type in a data block by predicting the data types within said data block.

Abstract: Methods, devices and systems enhance compression and decompression of data blocks of data values by selecting the best suited compression method and device among two or a plurality of compression methods and devices, which are combined together and which said compression methods and devices compress effectively data values of particular data types; said best suited compression method and device is selected using as main selection criterion the dominating data type in a data block by predicting the data types within said data block.

Abstract: Methods, devices and systems enhance compression and decompression of data values when they comprise a plurality of semantically meaningful data fields. Compression is sometimes not applied to each data value as a whole, but instead to at least one of the semantically meaningful data fields of each data value, and in isolation from the other ones. Data fields can be organized that share the same semantic meaning together to accelerate compression and decompression as multiple compressors and decompressors can be used in parallel. A system can be used where methods and devices are tailored to perform compression and decompression of the semantically meaningful data fields of floating-point numbers after first partitioning further at least one of said data fields into two or a plurality of sub-fields to increase the degree of value locality and improve compressibility of floating-point values.

Abstract: Methods, devices and systems extend a compressor and a decompressor for encoding and decoding data in the cache/memory/data transferring subsystem in a computer system or in a communication network. An example variable-length compressor is extended to be able to compress blocks of data values and said compressed blocks comprise mixes of compressed and uncompressed values, wherein metadata in the form of a unique special-meaning codeword (UUIC) indicates uncompressed values. An example variable-length decompressor is extended to be able to decompress said compressed data blocks that comprise mixes of compressed and uncompressed data values. Said compressor and decompressor are extended to support compression and decompression of common compression scenarios that are used in combination with variable-length compression to improve compressibility in the cache/memory/data transferring subsystem in a computer system or in a communication network.

Abstract: Methods, devices and systems extend a compressor and a decompressor for encoding and decoding data in the cache/memory/data transferring subsystem in a computer system or in a communication network. Example variable-length compressors and decompressors are extended with new features to: compress more densely when specific values occur in specific positions in a data block; to improve compression and decompression latency when specific values that are appear frequent occur in a data block; to also improve decompression latency by recording the lengths of variable-length encoded values of a compressed data block. Said compressor and decompressor are extended to support compression and decompression of common compression scenarios that are used in combination with variable-length compression to improve compressibility in the cache/memory/data transferring subsystem in a computer system or in a communication network.

Abstract: Methods, devices and systems enhance compression and decompression of data values when they comprise a plurality of semantically meaningful data fields. According to a first inventive concept of the present invention disclosure, compression is not applied to each data value as a whole, but instead to at least one of the semantically meaningful data fields of each data value, and in isolation from the other ones. A second inventive concept organizes the data fields that share the same semantic meaning together to accelerate compression and decompression as multiple compressors and decompressors can be used in parallel. A third inventive concept is a system where methods and devices are tailored to perform compression and decompression of the semantically meaningful data fields of floating-point numbers after first partitioning further at least one of said data fields into two or a plurality of sub-fields to increase the degree of value locality and improve compressibility of floating-point values.