base: disable FastAlloc in debug builds by default

FastAlloc's reuse policies can mask allocation bugs, so
we typically want it disabled when debugging.  Set
FORCE_FAST_ALLOC to enable even when debugging, and set
NO_FAST_ALLOC to disable even in non-debug builds.
This commit is contained in:
Steve Reinhardt 2011-03-18 11:47:11 -07:00
parent 6daf44dae6
commit 38aa50bb49
3 changed files with 16 additions and 189 deletions

View file

@ -822,8 +822,8 @@ sticky_vars.AddVariables(
sorted(n for n,m in CpuModel.dict.iteritems() if m.default),
sorted(CpuModel.list)),
BoolVariable('NO_FAST_ALLOC', 'Disable fast object allocator', False),
BoolVariable('FAST_ALLOC_DEBUG', 'Enable fast object allocator debugging',
False),
BoolVariable('FORCE_FAST_ALLOC',
'Enable fast object allocator, even for m5.debug', False),
BoolVariable('FAST_ALLOC_STATS', 'Enable fast object allocator statistics',
False),
BoolVariable('EFENCE', 'Link with Electric Fence malloc debugger',
@ -844,7 +844,7 @@ sticky_vars.AddVariables(
# These variables get exported to #defines in config/*.hh (see src/SConscript).
export_vars += ['FULL_SYSTEM', 'USE_FENV', 'USE_MYSQL',
'NO_FAST_ALLOC', 'FAST_ALLOC_DEBUG', 'FAST_ALLOC_STATS',
'NO_FAST_ALLOC', 'FORCE_FAST_ALLOC', 'FAST_ALLOC_STATS',
'SS_COMPATIBLE_FP', 'USE_CHECKER', 'TARGET_ISA', 'CP_ANNOTATE',
'USE_POSIX_CLOCK' ]

View file

@ -38,7 +38,7 @@
#include "base/fast_alloc.hh"
#if !NO_FAST_ALLOC
#if USE_FAST_ALLOC
#ifdef __GNUC__
#pragma implementation
@ -73,156 +73,4 @@ FastAlloc::moreStructs(int bucket)
return (p + sz);
}
#if FAST_ALLOC_DEBUG
#include <map>
#include <string>
#include <typeinfo>
#include "base/cprintf.hh"
#include "sim/core.hh" // for curTick()
using namespace std;
// count of in-use FastAlloc objects
int FastAlloc::numInUse;
// dummy head & tail object for doubly linked list of in-use FastAlloc
// objects
FastAlloc FastAlloc::inUseHead(&FastAlloc::inUseHead, &FastAlloc::inUseHead);
// special constructor for dummy head: make inUsePrev & inUseNext
// point to self
FastAlloc::FastAlloc(FastAlloc *prev, FastAlloc *next)
{
inUsePrev = prev;
inUseNext = next;
}
// constructor: marks as in use, add to in-use list
FastAlloc::FastAlloc()
{
// mark this object in use
inUse = true;
whenAllocated = curTick();
// update count
++numInUse;
// add to tail of list of in-use objects ("before" dummy head)
FastAlloc *myNext = &inUseHead;
FastAlloc *myPrev = inUseHead.inUsePrev;
inUsePrev = myPrev;
inUseNext = myNext;
myPrev->inUseNext = this;
myNext->inUsePrev = this;
}
// destructor: mark not in use, remove from in-use list
FastAlloc::~FastAlloc()
{
assert(inUse);
inUse = false;
--numInUse;
assert(numInUse >= 0);
// remove me from in-use list
inUsePrev->inUseNext = inUseNext;
inUseNext->inUsePrev = inUsePrev;
}
// Note that in all the display functions below we suppress anything
// with a zero allocation timestamp... there are a bunch of static or
// quasi-static structures that get allocated during initialization
// and we generally don't care about them so this gets them out of the
// way.
// summarize in-use list
void
FastAlloc::dump_summary()
{
map<string, int> typemap;
for (FastAlloc *p = inUseHead.inUseNext; p != &inUseHead; p = p->inUseNext)
{
if (p->whenAllocated != 0)
++typemap[typeid(*p).name()];
}
map<string, int>::const_iterator mapiter;
cprintf(" count type\n"
" ----- ----\n");
for (mapiter = typemap.begin(); mapiter != typemap.end(); ++mapiter)
cprintf("%6d %s\n",mapiter->second, mapiter->first);
}
// show oldest n items on in-use list
void
FastAlloc::dump_oldest(int n)
{
// sanity check: don't want to crash the debugger if you forget to
// pass in a parameter
if (n < 0 || n > numInUse) {
cprintf("FastAlloc::dump_oldest: bad arg %d (%d objects in use)\n",
n, numInUse);
return;
}
for (FastAlloc *p = inUseHead.inUseNext;
p != &inUseHead && n > 0;
p = p->inUseNext, --n) {
if (p->whenAllocated != 0)
cprintf("%x %15d %s\n", p, p->whenAllocated, typeid(*p).name());
}
}
// show oldest n items on in-use list for specified type
void
FastAlloc::dump_oldest_of_type(int n, const char *type_name)
{
// sanity check: don't want to crash the debugger if you forget to
// pass in a parameter
if (n < 0 || n > numInUse) {
cprintf("FastAlloc::dump_oldest_of_type: bad arg %d "
"(%d objects in use)\n",
n, numInUse);
return;
}
for (FastAlloc *p = inUseHead.inUseNext;
p != &inUseHead && n > 0;
p = p->inUseNext) {
if (p->whenAllocated != 0 &&
strcmp(typeid(*p).name(), type_name) == 0) {
cprintf("%x %15d\n", p, p->whenAllocated);
--n;
}
}
}
//
// C interfaces to FastAlloc::dump_summary() and FastAlloc::dump_oldest().
// gdb seems to have trouble with calling C++ functions directly.
//
void
fast_alloc_summary()
{
FastAlloc::dump_summary();
}
void
fast_alloc_oldest(int n)
{
FastAlloc::dump_oldest(n);
}
#endif // FAST_ALLOC_DEBUG
#endif // NO_FAST_ALLOC
#endif // USE_FAST_ALLOC

View file

@ -63,10 +63,18 @@
// hierarchy.
#include "config/no_fast_alloc.hh"
#include "config/fast_alloc_debug.hh"
#include "config/force_fast_alloc.hh"
#include "config/fast_alloc_stats.hh"
#if NO_FAST_ALLOC
// By default, we want to enable FastAlloc in any build other than
// m5.debug. (FastAlloc's reuse policies can mask allocation bugs, so
// we typically want it disabled when debugging.) Set
// FORCE_FAST_ALLOC to enable even when debugging, and set
// NO_FAST_ALLOC to disable even in non-debug builds.
#define USE_FAST_ALLOC \
(FORCE_FAST_ALLOC || (!defined(DEBUG) && !NO_FAST_ALLOC))
#if !USE_FAST_ALLOC
class FastAlloc
{
@ -74,10 +82,6 @@ class FastAlloc
#else
#if FAST_ALLOC_DEBUG
#include "base/types.hh"
#endif
class FastAlloc
{
public:
@ -87,13 +91,7 @@ class FastAlloc
void *operator new(size_t);
void operator delete(void *, size_t);
#if FAST_ALLOC_DEBUG
FastAlloc();
FastAlloc(FastAlloc *, FastAlloc *); // for inUseHead, see below
virtual ~FastAlloc();
#else
virtual ~FastAlloc() {}
#endif
private:
@ -125,25 +123,6 @@ class FastAlloc
static unsigned deleteCount[Num_Buckets];
static unsigned allocCount[Num_Buckets];
#endif
#if FAST_ALLOC_DEBUG
// per-object debugging fields
bool inUse; // in-use flag
FastAlloc *inUsePrev; // ptrs to build list of in-use objects
FastAlloc *inUseNext;
Tick whenAllocated;
// static (global) debugging vars
static int numInUse; // count in-use objects
static FastAlloc inUseHead; // dummy head for list of in-use objects
public:
// functions to dump debugging info (see fast_alloc.cc for C
// versions that might be more agreeable to call from gdb)
static void dump_summary();
static void dump_oldest(int n);
static void dump_oldest_of_type(int n, const char *type_name);
#endif
};
inline int
@ -206,6 +185,6 @@ FastAlloc::operator delete(void *p, size_t sz)
deallocate(p, sz);
}
#endif // NO_FAST_ALLOC
#endif // USE_FAST_ALLOC
#endif // __BASE_FAST_ALLOC_HH__