Date: Wed, 23 Oct 1996 13:42:54 -0700 (PDT) From: "Steven G. Kargl" <sgk@troutmask.apl.washington.edu> To: freebsd-current@freebsd.org Subject: Is profiling code broken? Message-ID: <199610232042.NAA05182@troutmask.apl.washington.edu>
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In my battle to increase the speed of some of my computations, I
will compile the code with profiling enabled. Today, to my
surprise my code seems to be executing infinitely fast.
This is on a -current machine that was last build on 9 Oct 96.
I'm in the process of doing a make world on freshly supped
sources.
For those who are programming language impaired, this is Fortran :-).
program t
implicit none
double precision x, f
integer i, j
external f
do 1 i =1, 1000
do 2 j = 1, 1000
x = f(dble(i))
2 continue
1 continue
end
double precision function f(x)
double precision x
integer i
do 3 i = 1, 100
f = x / 2.d0
3 continue
return
end
kargl[264] f77 -o t -pg t.f
kargl[265] time t
59.80 real 0.00 user 48.34 sys
kargl[266] gprof -l -b t gmon.out | more
granularity: each sample hit covers 4 byte(s) no time accumulated
% cumulative self self total
time seconds seconds calls ms/call ms/call name
0.0 0.00 0.00 1000000 0.00 0.00 _f_ [11]
0.0 0.00 0.00 6 0.00 0.00 _sigaction [12]
0.0 0.00 0.00 6 0.00 0.00 _signal [13]
0.0 0.00 0.00 5 0.00 0.00 ___syscall [14]
0.0 0.00 0.00 4 0.00 0.00 ___sseek [15]
0.0 0.00 0.00 4 0.00 0.00 _ftell [16]
0.0 0.00 0.00 4 0.00 0.00 _imalloc <cycle 1> [17]
0.0 0.00 0.00 4 0.00 0.00 _ioctl [18]
0.0 0.00 0.00 4 0.00 0.00 _isatty [19]
0.0 0.00 0.00 4 0.00 0.00 _lseek [20]
0.0 0.00 0.00 4 0.00 0.00 _sbrk [21]
0.0 0.00 0.00 4 0.00 0.00 _tcgetattr [22]
0.0 0.00 0.00 3 0.00 0.00 ___sflush [23]
There appears to be about 11 seconds missing from the time command
that should be accounted for by gprof.
Additionally, I noticed that the profiled libraries built during a
make world use a -p flag instead of -pg. Why? We do not currently
have prof(1) in the source tree.
--
Steve
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