RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 09:58:11 +00:00
Code Issues Activity Actions

LibC: Allow opting into malloc() and free() performance event logging

Browse source 
If a program is started with LIBC_PROFILE_MALLOC in the environment,
it will now generate PERF_EVENT_MALLOC and PERF_EVENT_FREE.
This commit is contained in:
Andreas Kling 2020-02-02 20:28:29 +01:00
parent 3879e5b9d4
commit fa97ff1c83
4 changed files with 32 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

25
Libraries/LibC/malloc.cpp
View file

@ -57,6 +57,7 @@ constexpr int number_of_big_blocks_to_keep_around_per_size_class = 8;
static bool s_log_malloc = false;
static bool s_scrub_malloc = true;
static bool s_scrub_free = true;
static bool s_profiling = false;
static unsigned short size_classes[] = { 8, 16, 32, 64, 128, 252, 508, 1016, 2036, 0 };
static constexpr size_t num_size_classes = sizeof(size_classes) / sizeof(unsigned short);
@ -170,7 +171,7 @@ static void os_free(void* ptr, size_t size)
assert(rc == 0);
}
void* malloc(size_t size)
static void* malloc_impl(size_t size)
{
LOCKER(malloc_lock());
@ -266,7 +267,7 @@ void* malloc(size_t size)
return ptr;
}
void free(void* ptr)
static void free_impl(void* ptr)
{
ScopedValueRollback rollback(errno);
@ -352,6 +353,21 @@ void free(void* ptr)
}
}
void* malloc(size_t size)
{
void* ptr = malloc_impl(size);
if (s_profiling)
perf_event(PERF_EVENT_MALLOC, size, reinterpret_cast<uintptr_t>(ptr));
return ptr;
}
void free(void* ptr)
{
if (s_profiling)
perf_event(PERF_EVENT_FREE, reinterpret_cast<uintptr_t>(ptr), 0);
free_impl(ptr);
}
void* calloc(size_t count, size_t size)
{
size_t new_size = count * size;
@ -396,6 +412,8 @@ void __malloc_init()
s_scrub_free = false;
if (getenv("LIBC_LOG_MALLOC"))
s_log_malloc = true;
if (getenv("LIBC_PROFILE_MALLOC"))
s_profiling = true;
g_allocators = (Allocator*)mmap_with_name(nullptr, sizeof(Allocator) * num_size_classes, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0, "LibC Allocators");
for (size_t i = 0; i < num_size_classes; ++i) {
@ -404,10 +422,9 @@ void __malloc_init()
}
g_big_allocators = (BigAllocator*)mmap_with_name(nullptr, sizeof(BigAllocator), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0, "LibC BigAllocators");
new (g_big_allocators) (BigAllocator);
new (g_big_allocators)(BigAllocator);
// We could mprotect the mmaps here with atexit, but, since this method is called in _start before
// _init and __init_array entries, our mprotect method would always be the last thing run before _exit.
}
}