pmcstat(8) contains an option to output sampling data in a gmon format
compatible with gprof(1). Currently, it uses the default histcounter,
which is an (unsigned short). With large sets of sampling data, it
is possible to overflow the maximum value provided by an (unsigned
short).
This change adds the -e argument to pmcstat. If -e and -g are both
specified, pmcstat will use a histcounter type of uint64_t.
Differential Revision: https://reviews.freebsd.org/D4151
Reviewed by: jhb, bjk
Approved by: gnn (mentor)
MFC after: 1 month
Sponsored by: Juniper Networks
'-m <file>' spits out the given stream into <file> (eg, /dev/stdout).
However, it only resolves the first symbol; it doesn't parse the entire
callgraph. If it fails to lookup then it doesn't print anything.
'-a' instead does a symbol and file:line lookup for each address in each
callgraph and will happily print the address itself with no lookup
information if it couldn't look things up.
This makes it much easier to pull out individual records from a
pmc data file and look at the callgraph information without having to
hand-decode the addresses.
Sponsored by: Netflix, Inc.
ints. That fixes a first bug where pmcstat wasn't using the old
cpumask_t interface and now also brings the full support for more
than 32 cpus.
While here, make the functions pmcstat_clone_event_descriptor() and
pmcstat_get_cpumask() private to pmcstat.
The problem of assuming cpu dense masks still persists and should be
eventually fixed, as reported by avg.
Tested by: pluknet
Reviewed by: gnn
Approved by: re (kib)
- Kcachegrind (calltree) support with assembly/source
code mapping and call count estimator (-F).
- Top mode for calltree and callgraph plugin (-T).
MFC after: 1 month
This option prints the list of sampled PCs along with the function name,
the start and end addresses of this where their live within.
Reviewed by: jkoshy
Tested by: gnn
Sponsored by: Nokia
- Allow the "-t" option to take a regular expression naming command
line processes to attach process PMCs to.
- Update the manual page and add an example showing the use of the
new functionality.
- Update the (c) year on the affected source files.
- The '-c' option now takes a comma-separated list of CPU
numbers, or a literal '*' denoting all CPUs in the system.
Subsequent system PMCs are allocated on the CPUs so specified.
Change the default behaviour to allocate system PMCs on all CPUs,
not just CPU 0.
Update the manual page and add an example of how to use the new
functionality.
- Attach PMCs to a (commandline) child process more reliably. This
fixes a long standing bug in counting events incurred by short-lived
processes.
Kernel changes:
Inform hwpmc of executable objects brought into the system by
kldload() and mmap(), and of their removal by kldunload() and
munmap(). A helper function linker_hwpmc_list_objects() has been
added to "sys/kern/kern_linker.c" and is used by hwpmc to retrieve
the list of currently loaded kernel modules.
The unused `MAPPINGCHANGE' event has been deprecated in favour
of separate `MAP_IN' and `MAP_OUT' events; this change reduces
space wastage in the log.
Bump the hwpmc's ABI version to "2.0.00". Teach hwpmc(4) to
handle the map change callbacks.
Change the default per-cpu sample buffer size to hold
32 samples (up from 16).
Increment __FreeBSD_version.
libpmc(3) changes:
Update libpmc(3) to deal with the new events in the log file; bring
the pmclog(3) manual page in sync with the code.
pmcstat(8) changes:
Introduce new options to pmcstat(8): "-r" (root fs path), "-M"
(mapfile name), "-q"/"-v" (verbosity control). Option "-k" now
takes a kernel directory as its argument but will also work with
the older invocation syntax.
Rework string handling in pmcstat(8) to use an opaque type for
interned strings. Clean up ELF parsing code and add support for
tracking dynamic object mappings reported by a v2.0.00 hwpmc(4).
Report statistics at the end of a log conversion run depending
on the requested verbosity level.
Reviewed by: jhb, dds (kernel parts of an earlier patch)
Tested by: gallatin (earlier patch)
- pmcstat(8) gprof output mode fixes:
lib/libpmc/pmclog.{c,h}, sys/sys/pmclog.h:
+ Add a 'is_usermode' field to the PMCLOG_PCSAMPLE event
+ Add an 'entryaddr' field to the PMCLOG_PROCEXEC event,
so that pmcstat(8) can determine where the runtime loader
/libexec/ld-elf.so.1 is getting loaded.
sys/kern/kern_exec.c:
+ Use a local struct to group the entry address of the image being
exec()'ed and the process credential changed flag to the exec
handling hook inside hwpmc(4).
usr.sbin/pmcstat/*:
+ Support "-k kernelpath", "-D sampledir".
+ Implement the ELF bits of 'gmon.out' profile generation in a new
file "pmcstat_log.c". Move all log related functions to this
file.
+ Move local definitions and prototypes to "pmcstat.h"
- Other bug fixes:
+ lib/libpmc/pmclog.c: correctly handle EOF in pmclog_read().
+ sys/dev/hwpmc_mod.c: unconditionally log a PROCEXIT event to all
attached PMCs when a process exits.
+ sys/sys/pmc.h: correct a function prototype.
+ Improve usage checks in pmcstat(8).
Approved by: re (blanket hwpmc)
