SLOB
Encyclopedia
The SLOB allocator is one of three available memory allocators in the Linux kernel
. (The other two are SLAB
and SLUB). The SLOB allocator is designed to be a small and efficient allocation framework for use in small systems such as embedded systems. Unfortunately, a major limitation of the SLOB allocator is that it suffers greatly from internal fragmentation.
SLOB currently uses a first-fit algorithm, which uses the first available space for memory. Recently a reply from Linus Torvalds
on a Linux mailing list were made where he suggested the use of a best-fit algorithm, which tries to find a memory block which suits needs best. Best fit finds the smallest space which fits the required amount available, avoiding loss of performance, both by fragmentation and consolidation of memory.
By default, Linux kernel uses a SLAB Allocation system
, and when the CONFIG_SLAB
flag is disabled, the kernel falls back to using the 'SLOB' allocator. The SLOB allocator was used in DSLinux
on Nintendo DS
handheld console.
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
. (The other two are SLAB
Slab allocation
Slab allocation is a memory management mechanism intended for the efficient memory allocation of kernel objects which displays the desirable property of eliminating fragmentation caused by allocations and deallocations. The technique is used to retain allocated memory that contains a data object of...
and SLUB). The SLOB allocator is designed to be a small and efficient allocation framework for use in small systems such as embedded systems. Unfortunately, a major limitation of the SLOB allocator is that it suffers greatly from internal fragmentation.
SLOB currently uses a first-fit algorithm, which uses the first available space for memory. Recently a reply from Linus Torvalds
Linus Torvalds
Linus Benedict Torvalds is a Finnish software engineer and hacker, best known for having initiated the development of the open source Linux kernel. He later became the chief architect of the Linux kernel, and now acts as the project's coordinator...
on a Linux mailing list were made where he suggested the use of a best-fit algorithm, which tries to find a memory block which suits needs best. Best fit finds the smallest space which fits the required amount available, avoiding loss of performance, both by fragmentation and consolidation of memory.
By default, Linux kernel uses a SLAB Allocation system
Slab allocation
Slab allocation is a memory management mechanism intended for the efficient memory allocation of kernel objects which displays the desirable property of eliminating fragmentation caused by allocations and deallocations. The technique is used to retain allocated memory that contains a data object of...
, and when the CONFIG_SLAB
flag is disabled, the kernel falls back to using the 'SLOB' allocator. The SLOB allocator was used in DSLinux
DSLinux
DSLinux is a port of the Linux operating system to the Nintendo DS. DSLinux was maintained until sometime in 2010.-Software:DSLinux runs a modified μClinux kernel. It is based on uCLinux 2.6.14 . It only runs in textmode and which is displayed using a custom framebuffer console driver...
on Nintendo DS
Nintendo DS
The is a portable game console produced by Nintendo, first released on November 21, 2004. A distinctive feature of the system is the presence of two separate LCD screens, the lower of which is a touchscreen, encompassed within a clamshell design, similar to the Game Boy Advance SP...
handheld console.