pmadvise -o option[,option] [-F] [-l] [-v] pid...
pmadvise applies advice about how memory is used in the specified process using madvise(3C).
pmadvise allows users to apply advice to a specific sub-range at a specific instant in time. pmadvise differs from madv.so.1(1) in that madv.so.1(1) applies the advice throughout execution of the target program to all segments of a specified type.
The following options are supported:
Force by grabbing the target process even if another process has control.
You should exercise caution when using the –F option. See proc(1).
Show unresolved dynamic linker map names.
Specify advice to apply in the following form:
private=advice shared=advice heap=advice stack=advice address[:length]=advice
where the advice can be one of the following:
normal random sequential willneed dontneed free access_lwp access_many access_many_pset access_default
An address and length can be given to specify a subrange to apply the advice. The address should be hexadecimal and the length should be in bytes by default.
If length is not specified and the starting address refers to the start of a segment, the advice is applied to that segment. length can be qualified by K, M, G, T, P, or E to specify kilobytes, megabytes, gigabytes, terabytes, or exabytes respectively as the unit of measure.
Print verbose output. Display output as pmap(1) does, showing what advice is being applied where. This can be useful when the advice is being applied to a named region (for example, private, shared, and so forth) to get feedback on exactly where the advice is being applied.
pmadvise tries to process all legal options. If an illegal address range is specified, an error message is printed and the offending option is skipped. pmadvise quits without processing any options and prints a usage message when there is a syntax error.
If conflicting advice is given on a region, the order of precedence is from most specific advice to least, that is, most general. In other words, advice specified for a particuliar address range takes precedence over advice for heap and stack which in turn takes precedence over advice for private and shared memory.
Moreover, the advice in each of the following groups are mutually exclusive from the other advice within the same group:
MADV_NORMAL, MADV_RANDOM, MADV_SEQUENTIAL MADV_WILLNEED, MADV_DONTNEED, MADV_FREE MADV_ACCESS_DEFAULT, MADV_ACCESS_LWP, MADV_ACCESS_MANY
The following operands are supported:
Process ID.
The following example applies advice to a segment at a specified address:
% pmap $$ 100666: tcsh 00010000 312K r-x-- /usr/bin/tcsh 0006C000 48K rwx-- /usr/bin/tcsh 00078000 536K rwx-- [ heap ] FF100000 856K r-x-- /lib/libc.so.1 FF1E6000 32K rwx-- /lib/libc.so.1 FF1EE000 8K rwx-- /lib/libc.so.1 FF230000 168K r-x-- /lib/libcurses.so.1 FF26A000 32K rwx-- /lib/libcurses.so.1 FF272000 8K rwx-- /lib/libcurses.so.1 FF280000 576K r-x-- /lib/libnsl.so.1 FF310000 40K rwx-- /lib/libnsl.so.1 FF31A000 24K rwx-- /lib/libnsl.so.1 FF364000 8K rwxs- [ anon ] FF370000 48K r-x-- /lib/libsocket.so.1 FF38C000 8K rwx-- /lib/libsocket.so.1 FF3B0000 176K r-x-- /lib/ld.so.1 FF3EC000 8K rwx-- /lib/ld.so.1 FF3EE000 8K rwx-- /lib/ld.so.1 FFBE6000 104K rw--- [ stack ] % % pmadvise -o 78000=access_lwp $$ %Example 2 Using the –v Option
The following example displays verbose output from pmadvise:
% pmadvise -o heap=access_lwp,stack=access_default -v $$ 1720: -sh 00010000 88K r-x-- /usr/sbin/sh 00036000 8K rwx-- /usr/sbin/sh 00038000 16K rwx-- [ heap ] <= access_lwp FF250000 24K r-x-- /lib/libgen.so.1 FF266000 8K rwx-- /lib/libgen.so.1 FF272000 8K rwxs- [ anon ] FF280000 840K r-x-- /lib/libc.so.1 FF362000 32K rwx-- /lib/libc.so.1 FF36A000 16K rwx-- /lib/libc.so.1 FF390000 64K rwx-- [ anon ] FF3B0000 168K r-x-- /lib/ld.so.1 FF3EA000 8K rwx-- /lib/ld.so.1 FF3EC000 8K rwx-- /lib/ld.so.1 FFBFE000 8K rw--- [ stack ] <= access_default
The following exit values are returned:
Successful completion.
An error occurred.
Process files
proc tools support files
See attributes(5) for descriptions of the following attributes:
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The command syntax is Committed. The output formats are Uncommitted.