appear to be never called:
(1) If a function is never called according to its call count but it
must have been called because its child time is nonzero, then print
it in the flat profile. Previously, if its call count was zero
then we only printed it in the flat profile if its self time was
nonzero.
(2) If a function has a zero call count but has a nonzero self or child
time, then print its total self time in the self time per call
column as a percentage of the total (self + child) time. It is
not possible to print the times per call in this case because the
call count is zero. Previously, this was handled by leaving both
per-call columns blank. The self time is printed in another column
but there was no way to recover the total time.
(1) partially fixes the case of the "never called" function main() and
prepares for (2) to apply to main() and other functions. Profiling
of main() was lost in the conversion from a.out to ELF, so main()'s
call count has always been zero for many years; then in the common
case where main() is a tiny function, it gets no profiling ticks, so
main() was completely lost in the flat profile.
(2) improves mainly cases like kernel threads. Most kernel threads
appear to be never called because they are always started before
userland can run to turn on profiling. As for main(), the fact that
they are called is not very interesting and their callers are
uninteresting, but their relative self time is interesting since they
are long-running.
Almost always printing percentages in the per-call columns would be
more useful than almost always printing 0.0ms. 0.1ms is now a long
time, so only very large functions take that long per call. The accuracy
per call can approach 1-10 nsec provided programs are run for about
100000 times as long as is necessary to get this accuracy with high
resolution kernel profiling.
on allocation failure instead of displaying a warning and deferencing NULL
pointer after. Spelling. Add prototypes. Add list of option in synopsis section
of man page, -d is not referenced because available as a compile option. It
should be made a runtime option btw.
generated the gmon data. The support is currently limited to what is
easy to implement and/or needed:
signedess: signed or insigned
size: 8, 16, 32 or 64 bits
format: a binary integer in gprof's format (gprof is not a cross-tool).
High-resolution kernel profiling uses signed 64-bit counters. Normal
kernel profiling and user profiling use unsigned 16-bit counters but
should use 32-bit ones.
things when sizeof(UNIT) becomes a runtime parameter. The relevant 2
is the one in profil(2)'s scaling of pc's to bucket numbers:
bucket = (pc - offset) / 2 * profil_scale / 65536
gprof(1) must duplicate this scaling, bug for bug compatibly, so it
must first do an integer division by 2 although this mainly makes
scales larger than 65536 useless. sizeof(UNIT) was already wrong in
gprof4, but there were no problems because the fake profil scale is a
multiple of 2.
There are also some rounding bugs in the scaling, but these are only
problems if profil(2) is used directly to create unusual (and not
useful) scales.
without possibly losing lots of precision, and print the scale using
%g instead of %d in case it is non-integral. %g might not be the best
format for this.
was split off from gprof.c in rev.1.7 of the latter. elf.c is mostly new,
but the old copyright sort of applies to it and is better than none.
Use __FBSDID() for the FreeBSD id.
from <number of machines> machine-dependent headers to the one
non-header here it is used so that it is easier to fix. This macro
just divides the machine-dependent offset OFFSET_OF_CODE by the
machine-independent scale factor sizeof(UNIT), as required for bug
for bug compatibility with the scaling of pc's in gprof.c. UNIT is
the type of a profiling counter, and its size has nothing to do with
the correct scale factor except both are usually 2.
the currently-running kernel (and supercedes an executable file argument
given). With this change, properly-compiled KLD modules are now
able to be profiled.
Obtained from: NAI Labs CBOSS project
Funded by: DARPA
longer includes machine/elf.h.
* consumers of elf.h now use the minimalist elf header possible.
This change is motivated by Binutils 2.11.0 and too much clashing over
our base elf headers and the Binutils elf headers.
