On Thu, Nov 4, 2010 at 8:03 PM, kernel.niko <kernel.niko@xxxxxxxxx> wrote: > hi,everyone, > I'm wandering how to use kmalloc and kmem_cache_alloc. > as i know,kmalloc is based on kmem_cache_alloc ,so what's the different? kmalloc should be used when you want to allocate byte sized memory as opposed to allocating memory in units of pages, in which case you should use alloc_pages(..). kmem_cache_alloc is a part of the slab cache interface. This is used for reusing objects in the kernel. Lets take mm_struct objects as an example. On a live system, processes come & go. Every process needs a mm_struct object. And when a process dies, you can throw away the object. Instead of creating & throwing away objects, slab cache maintains a cache of objects. When you free an object, instead of deallocating it, you give it back to the cache. Next time, if you want to create a new object, slab cache gives you one object from the slab cache. kmem_cache_alloc is one of the interface functions to use the slab cache in the kernel. You might want to read about slab caches in detail if you need more information. Venkatram Tummala > when to use kmalloc? and > in what occasion,kmem_cache_alloc should be used? > thanks. > > 2010-11-05 > ________________________________ > kernel.niko -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
