madv.so.1(1)							   User Commands						      madv.so.1(1)

NAME

       madv.so.1 - madv library

SYNOPSIS

       /usr/lib/madv.so.1

DESCRIPTION

       The madv.so.1 shared object provides a means by which the VM advice can be selectively configured for a launched process (or processes) and
       its descendants. To enable madv.so.1, the following string needs to be present in the environment (see ld.so.1(1)) along with one  or  more
       MADV environment variables:

       LD_PRELOAD=$LD_PRELOAD:madv.so.1

ENVIRONMENT VARIABLES

       If  the madv.so.1 shared object is specified in the LD_PRELOAD list, the following environment variables are read by the madv shared object
       to determine to which created process(es) to apply the specified advice.

       MADV=advice

	   MADV specifies the VM advice to use for all heap, shared memory, and mmap regions in the process  address		      space.  This
	   advice is applied to all created processes.

	   Values for advice correspond to values in <sys/mman.h> used in madvise(3C) to specify memory access patterns:

			normal

			random

			sequential

			access_lwp

			access_many

			access_default

   MADVCFGFILE=config-file

       config-file is a text file which contains one or more madv configuration entries of the form:

       exec-name exec-args:advice-opts

       Advice  specified in config-file takes precedence over that specified by the MADV environment variable. When MADVCFGFILE is not set, advice
       is taken from file /etc/madv.conf if it exists.

       exec-name specifies the name of an application or executable. The corresponding advice is set for newly	created  processes  (see  getexec-
       name(3C)) that match the first exec-name found in the file.

       exec-name can be a full pathname, a base name, or a pattern string. See File Name Generation in sh(1) for a discussion of pattern matching.

       exec-args  is an optionally specified pattern string to match against arguments. Advice is set only if exec-args is not specified or occurs
       within the arguments to exec-name.

       advice-opts is a comma-separated list specifying the advice for various memory region(s):

       madv=advice	       Applies to all heap, shared memory, and mmap regions in the process address space.

       heap=advice	       The heap is defined to be the brk area (see brk(2)). Applies to the existing heap and for any additional heap  mem-
			       ory allocated in the future.

       shm=advice	       Shared  memory  segments (see shmat(2)) attached using any flags, flag SHM_SHARE_MMU, or flag SHM_PAGEABLE  respec-
       ism=advice	       tively. Options ism and dism take precedence over option shm.
       dism=advice

       map=advice	       Mappings established through mmap(2) using any flags, flag MAP_SHARED, flag MAP_PRIVATE, or flag MAP_ANON,  respec-
       mapshared=advice        tively. Options mapshared, mapprivate, and mapanon take precedence over option map. Option mapanon takes precedence
       mapprivate=advice       over mapshared and mapprivate.
       mapanon=advice

   MADVERRFILE=pathname

       By default, error messages are logged via syslog(3C) using level LOG_ERR and facility LOG_USER. If MADVERRFILE contains	a  valid  pathname
       (such as /dev/stderr), error messages will be logged there instead.

EXAMPLES

       Example 1: Applying advice to all ISM segments

       The following configuration applies advice to all ISM segments for application /usr/bin/foo:

       example$ LD_PRELOAD=$LD_PRELOAD:madv.so.1
       example$ MADVCFGFILE=madvcfg
       example$ export LD_PRELOAD MADVCFGFILE
       example$ cat $MADVCFGFILE
	   /usr/bin/foo:ism=access_lwp

       Example 2: Setting advice for all applications with exception

       The following configuration sets advice for all applications with the exception of ls.

       example$ LD_PRELOAD=$LD_PRELOAD:madv.so.1
       example$ MADV=access_many
       example$ MADVCFGFILE=madvcfg
       example$ export LD_PRELOAD MADV MADVCFGFILE
       example$ cat $MADVCFGFILE
	   ls:

       Example 3: Precedence rules (continuation from Example 2)

       Because	MADVCFGFILE  takes precedence over MADV, specifying '*' (pattern match all) for the exec-name of the last madv configuration entry
       would be equivalent to setting MADV. The following is equivalent to example 2:

       example$ LD_PRELOAD=$LD_PRELOAD:madv.so.1
       example$ MADVCFGFILE=madvcfg
       example$ export LD_PRELOAD MADVCFGFILE
       example$ cat $MADVCFGFILE
	   ls:
	   *:madv=access_many

       Example 4: Applying advice for different regions

       The following configuration applies one type of advice for mmap regions and different advice for heap  and  shared  memory  regions  for  a
       select set of applications with exec names that begin with foo:

       example$ LD_PRELOAD=$LD_PRELOAD:madv.so.1
       example$ MADVCFGFILE=madvcfg
       example$ export LD_PRELOAD MADVCFGFILE
       example$ cat $MADVCFGFILE
	   foo*:madv=access_many,heap=sequential,shm=access_lwp

       Example 5: Applying advice selectively

       The following configuration applies advice for the heap of applications beginning with ora that have ora1 as an argument:

       example$ LD_PRELOAD=$LD_PRELOAD:madv.so.1
       example$ MADVCFGFILE=madvcfg
       example$ export LD_PRELOAD MADVCFGFILE
       example$ cat $MADVCFGFILE
	   ora* ora1:heap=access_many

FILES

       /etc/madv.conf		       Configuration file

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWesu (32-bit)		   |
       +-----------------------------+-----------------------------+
       |			     |SUNWesxu (64-bit) 	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Unstable			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       cat(1),	ld.so.1(1),  proc(1),  sh(1),  brk(2),	exec(2), fork(2), mmap(2), memcntl(2), shmat(2), getexecname(3C), madvise(3C), syslog(3C),
       proc(4), attributes(5)

NOTES

       The advice is inherited. A child process has the same advice	    as its parent. On exec() (see exec(2)), the advice is set back to  the
       default system advice unless different advice has been configured via the madv shared object.

       Advice  is only applied to mmap regions explicitly created by the user program. Those regions established by the run-time linker or by sys-
       tem libraries making direct system calls (for example, libthread allocations for thread stacks) are not affected.

SunOS 5.10							    15 Feb 2002 						      madv.so.1(1)