bitmap_find_free_region(9) [centos man page]

BITMAP_FIND_FREE_REG(9) 				  Basic Kernel Library Functions				   BITMAP_FIND_FREE_REG(9)

NAME

       bitmap_find_free_region - find a contiguous aligned mem region

SYNOPSIS

       int bitmap_find_free_region(unsigned long * bitmap, int bits, int order);

ARGUMENTS

       bitmap
	   array of unsigned longs corresponding to the bitmap

       bits
	   number of bits in the bitmap

       order
	   region size (log base 2 of number of bits) to find

DESCRIPTION

       Find a region of free (zero) bits in a bitmap of bits bits and allocate them (set them to one). Only consider regions of length a power
       (order) of two, aligned to that power of two, which makes the search algorithm much faster.

       Return the bit offset in bitmap of the allocated region, or -errno on failure.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						   BITMAP_FIND_FREE_REG(9)

Slurm::Bitstr(3pm)					User Contributed Perl Documentation					Slurm::Bitstr(3pm)

NAME

       Slurm::Bitstr - Bitstring functions in libslurm

SYNOPSIS

	use Slurm;

	$bitmap = Slurm::Bitstr::alloc(32);
	if ($bitmap->test(10)) {
	       print "bit 10 is set
";
	}

DESCRIPTION

       The Slurm::Bitstr class is a wrapper of the bit string functions in libslurm. This package is loaded and bootstrapped with package Slurm.

METHODS

       $bitmap = Slurm::Bitstr::alloc($nbits);

       Allocate a bitstring object with $nbits bits. An opaque bitstr object is returned. This is a CLASS METHOD.

       $bitmap->realloc($nbits);

       Reallocate a bitstring(expand or contract size). $nbits is the number of bits in the new bitstring.

       $len = $bitmap->size();

       Return the number of possible bits in a bitstring.

       $cond = $bitmap->test($n);

       Check if bit $n of $bitmap is set.

       $bitmap->set($n);

       Set bit $n of $bitmap.

       $bitmap->clear($n);

       Clear bit $n of $bitmap.

       $bitmap->nset($start, $stop);

       Set bits $start .. $stop in $bitmap.

       $bitmap->nclear($start, $stop);

       Clear bits $start .. $stop in $bitmap.

       $pos = $bitmap->ffc();

       Find first bit clear in $bitmap.

       $pos = $bitmap->nffc($n)

       Find the first $n contiguous bits clear in $bitmap.

       $pos = $bitmap->noc($n, $seed);

       Find $n contiguous bits clear in $bitmap starting at offset $seed.

       $pos = $bitmap->nffs($n);

       Find the first $n contiguous bits set in $bitmap.

       $pos = $bitmap->ffs();

       Find first bit set in $bitmap;

       $pos = $bitmap->fls();

       Find last bit set in $bitmap;

       $bitmap->fill_gaps();

       Set all bits of $bitmap between the first and last bits set(i.e. fill in the gaps to make set bits contiguous).

       $cond = $bitmap1->super_set($bitmap2);

       Return 1 if all bits set in $bitmap1 are also set in $bitmap2, 0 otherwise.

       $cond = $bitmap1->equal($bitmap2);

       Return 1 if $bitmap1 and $bitmap2 are identical, 0 otherwise.

       $bitmap1->and($bitmap2);

       $bitmap1 &= $bitmap2.

       $bitmap->not();

       $bitmap = ~$bitmap.

       $bitmap1->or($bitmap2);

       $bitmap1 |= $bitmap2.

       $new = $bitmap->copy();

       Return a copy of the supplied bitmap.

       $dest_bitmap->copybits($src_bitmap);

       Copy all bits of $src_bitmap to $dest_bitmap.

       $n = $bitmap->set_count();

       Count the number of bits set in bitstring.

       $n = $bitmap1->overlap($bitmap2);

       Return number of bits set in $bitmap1 that are also set in $bitmap2, 0 if no overlap.

       $n = $bitmap->clear_count();

       Count the number of bits clear in bitstring.

       $n = $bitmap->nset_max_count();

       Return the count of the largest number of contiguous bits set in $bitmap.

       $sum = $bitmap->inst_and_set_count($int_array);

       And $int_array and $bitmap and sum the elements corresponding to set entries in $bitmap.

       $new = $bitmap->rotate_copy($n, $nbits);

       Return a copy of $bitmap rotated by $n bits. Number of bit in the new bitmap is $nbits.

       $bitmap->rotate($n);

       Rotate $bitmap by $n bits.

       $new = $bitmap->pick_cnt($nbits);

       Build a bitmap containing the first $nbits of $bitmap which are set.

       $str = $bitmap->fmt();

       Convert $bitmap to range string format, e.g. 0-5,42

       $rc = $bitmap->unfmt($str);

       Convert range string format to bitmap.

       $array = Slurm::Bitstr::bitfmt2int($str);

       Convert $str describing bitmap (output from fmt(), e.g. "0-30,45,50-60") into an array of integer (start/edn) pairs terminated by -1 (e.g.
       "0, 30, 45, 45, 50, 60, -1").

       $str = $bitmap->fmt_hexmask();

       Given a bit string, allocate and return a string in the form of:
	   "0x0123ABC"
	      ^     ^
	      |     |
	     MSB   LSB

       $rc = $bitmap->unfmt_hexmask($str);

       Give a hex mask string "0x0123ABC", convert to a bit string.
				 ^     ^
				 |     |
				MSB   LSB

       $str = $bitmap->fmt_binmask();

       Given a bit string, allocate and return a binary string in the form of:
				   "0001010"
				    ^	  ^
				    |	  |
				   MSB	 LSB

       $rc = $bitmap->unfmt_binmask($str);

       Give a bin mask string "0001010", convert to a bit string.
			       ^     ^
			       |     |
			      MSB   LSB

       $pos = $bitmap->get_bit_num($n);

       Find position of the $n-th set bit(0 based, i.e., the first set bit is the 0-th) in $bitmap. Returns -1 if there are less than $n bits set.

       $n = $bitmap->get_pos_num($pos);

       Find the number of bits set minus one in $bitmap between bit postion [0 .. $pos]. Returns -1 if no bits are set between [0 .. $pos].

SEE ALSO

       Slurm

AUTHOR

       This library is created by Hongjia Cao, <hjcao(AT)nudt.edu.cn> and Danny Auble, <da(AT)llnl.gov>. It is distributed with SLURM.

COPYRIGHT AND LICENSE

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.4 or,
       at your option, any later version of Perl 5 you may have available.

perl v5.14.2							    2012-03-16							Slurm::Bitstr(3pm)