__alloc_skb(9) [centos man page]

__ALLOC_SKB(9)							 Linux Networking						    __ALLOC_SKB(9)

NAME

       __alloc_skb - allocate a network buffer

SYNOPSIS

       struct sk_buff * __alloc_skb(unsigned int size, gfp_t gfp_mask, int flags, int node);

ARGUMENTS

       size
	   size to allocate

       gfp_mask
	   allocation mask

       flags
	   If SKB_ALLOC_FCLONE is set, allocate from fclone cache instead of head cache and allocate a cloned (child) skb. If SKB_ALLOC_RX is set,
	   __GFP_MEMALLOC will be used for allocations in case the data is required for writeback

       node
	   numa node to allocate memory on

DESCRIPTION

       Allocate a new sk_buff. The returned buffer has no headroom and a tail room of at least size bytes. The object has a reference count of
       one. The return is the buffer. On a failure the return is NULL.

       Buffers may only be allocated from interrupts using a gfp_mask of GFP_ATOMIC.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							    __ALLOC_SKB(9)

KCALLOC(9)						    Memory Management in Linux							KCALLOC(9)

NAME

       kcalloc - allocate memory for an array. The memory is set to zero.

SYNOPSIS

       void * kcalloc(size_t n, size_t size, gfp_t flags);

ARGUMENTS

       n
	   number of elements.

       size
	   element size.

       flags
	   the type of memory to allocate.

DESCRIPTION

       The flags argument may be one of:

       GFP_USER - Allocate memory on behalf of user. May sleep.

       GFP_KERNEL - Allocate normal kernel ram. May sleep.

       GFP_ATOMIC - Allocation will not sleep. May use emergency pools. For example, use this inside interrupt handlers.

       GFP_HIGHUSER - Allocate pages from high memory.

       GFP_NOIO - Do not do any I/O at all while trying to get memory.

       GFP_NOFS - Do not make any fs calls while trying to get memory.

       GFP_NOWAIT - Allocation will not sleep.

       GFP_THISNODE - Allocate node-local memory only.

       GFP_DMA - Allocation suitable for DMA. Should only be used for kmalloc caches. Otherwise, use a slab created with SLAB_DMA.

       Also it is possible to set different flags by OR'ing in one or more of the following additional flags:

       __GFP_COLD - Request cache-cold pages instead of trying to return cache-warm pages.

       __GFP_HIGH - This allocation has high priority and may use emergency pools.

       __GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail (think twice before using).

       __GFP_NORETRY - If memory is not immediately available, then give up at once.

       __GFP_NOWARN - If allocation fails, don't issue any warnings.

       __GFP_REPEAT - If allocation fails initially, try once more before failing.

       There are other flags available as well, but these are not intended for general use, and so are not documented here. For a full list of
       potential flags, always refer to linux/gfp.h.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010								KCALLOC(9)