diff options
author | bde <bde@FreeBSD.org> | 1995-12-29 15:30:05 +0000 |
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committer | bde <bde@FreeBSD.org> | 1995-12-29 15:30:05 +0000 |
commit | 586cc683d875b37dce82c825feb9ccc7d884b35e (patch) | |
tree | 9ce1e55534d3d930aead3ff55aeb7fcedbc086a4 /sys/libkern | |
parent | ff6f507f6bbb3fda77fb14c7201db37bafea7a3f (diff) | |
download | FreeBSD-src-586cc683d875b37dce82c825feb9ccc7d884b35e.zip FreeBSD-src-586cc683d875b37dce82c825feb9ccc7d884b35e.tar.gz |
Implemented non-statistical kernel profiling. This is based on
looking at a high resolution clock for each of the following events:
function call, function return, interrupt entry, interrupt exit,
and interesting branches. The differences between the times of
these events are added at appropriate places in a ordinary histogram
(as if very fast statistical profiling sampled the pc at those
places) so that ordinary gprof can be used to analyze the times.
gmon.h:
Histogram counters need to be 4 bytes for microsecond resolutions.
They will need to be larger for the 586 clock.
The comments were vax-centric and wrong even on vaxes. Does anyone
disagree?
gprof4.c:
The standard gprof should support counters of all integral sizes
and the size of the counter should be in the gmon header. This
hack will do until then. (Use gprof4 -u to examine the results
of non-statistical profiling.)
config/*:
Non-statistical profiling is configured with `config -pp'.
`config -p' still gives ordinary profiling.
kgmon/*:
Non-statistical profiling is enabled with `kgmon -B'. `kgmon -b'
still enables ordinary profiling (and distables non-statistical
profiling) if non-statistical profiling is configured.
Diffstat (limited to 'sys/libkern')
-rw-r--r-- | sys/libkern/mcount.c | 182 |
1 files changed, 3 insertions, 179 deletions
diff --git a/sys/libkern/mcount.c b/sys/libkern/mcount.c index fc3625b..ed0e68d 100644 --- a/sys/libkern/mcount.c +++ b/sys/libkern/mcount.c @@ -1,180 +1,4 @@ -/*- - * Copyright (c) 1983, 1992, 1993 - * The Regents of the University of California. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * $Id: mcount.c,v 1.3 1994/09/15 15:41:48 paul Exp $ - */ +#define GPROF4 1 /* XXX can't get at kernel options */ +#define GUPROF 1 /* XXX can't get at kernel options */ -#include <sys/param.h> -#include <sys/gmon.h> -#ifdef KERNEL -#include <i386/include/cpufunc.h> -#endif - -/* - * mcount is called on entry to each function compiled with the profiling - * switch set. _mcount(), which is declared in a machine-dependent way - * with _MCOUNT_DECL, does the actual work and is either inlined into a - * C routine or called by an assembly stub. In any case, this magic is - * taken care of by the MCOUNT definition in <machine/profile.h>. - * - * _mcount updates data structures that represent traversals of the - * program's call graph edges. frompc and selfpc are the return - * address and function address that represents the given call graph edge. - * - * Note: the original BSD code used the same variable (frompcindex) for - * both frompcindex and frompc. Any reasonable, modern compiler will - * perform this optimization. - */ -_MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */ - register u_long frompc, selfpc; -{ - register u_short *frompcindex; - register struct tostruct *top, *prevtop; - register struct gmonparam *p; - register long toindex; -#ifdef KERNEL - register int s; - u_long save_eflags; -#endif - - p = &_gmonparam; - /* - * check that we are profiling - * and that we aren't recursively invoked. - */ - if (p->state != GMON_PROF_ON) - return; -#ifdef KERNEL - MCOUNT_ENTER; -#else - p->state = GMON_PROF_BUSY; -#endif - /* - * check that frompcindex is a reasonable pc value. - * for example: signal catchers get called from the stack, - * not from text space. too bad. - */ - frompc -= p->lowpc; - if (frompc > p->textsize) - goto done; - - frompcindex = &p->froms[frompc / (p->hashfraction * sizeof(*p->froms))]; - toindex = *frompcindex; - if (toindex == 0) { - /* - * first time traversing this arc - */ - toindex = ++p->tos[0].link; - if (toindex >= p->tolimit) - /* halt further profiling */ - goto overflow; - - *frompcindex = toindex; - top = &p->tos[toindex]; - top->selfpc = selfpc; - top->count = 1; - top->link = 0; - goto done; - } - top = &p->tos[toindex]; - if (top->selfpc == selfpc) { - /* - * arc at front of chain; usual case. - */ - top->count++; - goto done; - } - /* - * have to go looking down chain for it. - * top points to what we are looking at, - * prevtop points to previous top. - * we know it is not at the head of the chain. - */ - for (; /* goto done */; ) { - if (top->link == 0) { - /* - * top is end of the chain and none of the chain - * had top->selfpc == selfpc. - * so we allocate a new tostruct - * and link it to the head of the chain. - */ - toindex = ++p->tos[0].link; - if (toindex >= p->tolimit) - goto overflow; - - top = &p->tos[toindex]; - top->selfpc = selfpc; - top->count = 1; - top->link = *frompcindex; - *frompcindex = toindex; - goto done; - } - /* - * otherwise, check the next arc on the chain. - */ - prevtop = top; - top = &p->tos[top->link]; - if (top->selfpc == selfpc) { - /* - * there it is. - * increment its count - * move it to the head of the chain. - */ - top->count++; - toindex = prevtop->link; - prevtop->link = top->link; - top->link = *frompcindex; - *frompcindex = toindex; - goto done; - } - - } -done: -#ifdef KERNEL - MCOUNT_EXIT; -#else - p->state = GMON_PROF_ON; -#endif - return; -overflow: - p->state = GMON_PROF_ERROR; -#ifdef KERNEL - MCOUNT_EXIT; -#endif - return; -} - -/* - * Actual definition of mcount function. Defined in <machine/profile.h>, - * which is included by <sys/gmon.h>. - */ -MCOUNT +#include "../lib/libc/gmon/mcount.c" /* XXX */ |