intel/llvm
1
0
Fork 0
mirror of https://github.com/intel/llvm.git synced 2026-01-19 09:31:59 +08:00
Code Issues Packages Projects Releases Wiki Activity

Added an allocated memory cache to avoid having to allocate memory over and

Browse Source 
over when running JITed expressions. The allocated memory cache will cache 
allocate memory a page at a time for each permission combination and divvy up
the memory and hand it out in 16 byte increments. 

llvm-svn: 131453
This commit is contained in:
Greg Clayton
2011-05-17 03:37:42 +00:00
parent a7ae4552af
commit d495c5340d
8 changed files with 658 additions and 191 deletions
Download Patch File Download Diff File Expand all files Collapse all files

167
lldb/source/Target/Process.cpp
View File

@@ -539,144 +539,6 @@ ProcessInstanceInfoMatch::Clear()
m_match_all_users = false;
}
//----------------------------------------------------------------------
// MemoryCache constructor
//----------------------------------------------------------------------
Process::MemoryCache::MemoryCache() :
m_cache_line_byte_size (512),
m_cache_mutex (Mutex::eMutexTypeRecursive),
m_cache ()
{
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
Process::MemoryCache::~MemoryCache()
{
}
void
Process::MemoryCache::Clear()
{
Mutex::Locker locker (m_cache_mutex);
m_cache.clear();
}
void
Process::MemoryCache::Flush (addr_t addr, size_t size)
{
if (size == 0)
return;
const uint32_t cache_line_byte_size = m_cache_line_byte_size;
const addr_t end_addr = (addr + size - 1);
const addr_t flush_start_addr = addr - (addr % cache_line_byte_size);
const addr_t flush_end_addr = end_addr - (end_addr % cache_line_byte_size);
Mutex::Locker locker (m_cache_mutex);
if (m_cache.empty())
return;
assert ((flush_start_addr % cache_line_byte_size) == 0);
for (addr_t curr_addr = flush_start_addr; curr_addr <= flush_end_addr; curr_addr += cache_line_byte_size)
{
collection::iterator pos = m_cache.find (curr_addr);
if (pos != m_cache.end())
m_cache.erase(pos);
}
}
size_t
Process::MemoryCache::Read
(
Process *process,
addr_t addr,
void *dst,
size_t dst_len,
Error &error
)
{
size_t bytes_left = dst_len;
if (dst && bytes_left > 0)
{
const uint32_t cache_line_byte_size = m_cache_line_byte_size;
uint8_t *dst_buf = (uint8_t *)dst;
addr_t curr_addr = addr - (addr % cache_line_byte_size);
addr_t cache_offset = addr - curr_addr;
Mutex::Locker locker (m_cache_mutex);
while (bytes_left > 0)
{
collection::const_iterator pos = m_cache.find (curr_addr);
collection::const_iterator end = m_cache.end ();
if (pos != end)
{
size_t curr_read_size = cache_line_byte_size - cache_offset;
if (curr_read_size > bytes_left)
curr_read_size = bytes_left;
memcpy (dst_buf + dst_len - bytes_left, pos->second->GetBytes() + cache_offset, curr_read_size);
bytes_left -= curr_read_size;
curr_addr += curr_read_size + cache_offset;
cache_offset = 0;
if (bytes_left > 0)
{
// Get sequential cache page hits
for (++pos; (pos != end) && (bytes_left > 0); ++pos)
{
assert ((curr_addr % cache_line_byte_size) == 0);
if (pos->first != curr_addr)
break;
curr_read_size = pos->second->GetByteSize();
if (curr_read_size > bytes_left)
curr_read_size = bytes_left;
memcpy (dst_buf + dst_len - bytes_left, pos->second->GetBytes(), curr_read_size);
bytes_left -= curr_read_size;
curr_addr += curr_read_size;
// We have a cache page that succeeded to read some bytes
// but not an entire page. If this happens, we must cap
// off how much data we are able to read...
if (pos->second->GetByteSize() != cache_line_byte_size)
return dst_len - bytes_left;
}
}
}
// We need to read from the process
if (bytes_left > 0)
{
assert ((curr_addr % cache_line_byte_size) == 0);
std::auto_ptr<DataBufferHeap> data_buffer_heap_ap(new DataBufferHeap (cache_line_byte_size, 0));
size_t process_bytes_read = process->ReadMemoryFromInferior (curr_addr,
data_buffer_heap_ap->GetBytes(),
data_buffer_heap_ap->GetByteSize(),
error);
if (process_bytes_read == 0)
return dst_len - bytes_left;
if (process_bytes_read != cache_line_byte_size)
data_buffer_heap_ap->SetByteSize (process_bytes_read);
m_cache[curr_addr] = DataBufferSP (data_buffer_heap_ap.release());
// We have read data and put it into the cache, continue through the
// loop again to get the data out of the cache...
}
}
}
return dst_len - bytes_left;
}
Process*
Process::FindPlugin (Target &target, const char *plugin_name, Listener &listener)
{
@@ -735,7 +597,8 @@ Process::Process(Target &target, Listener &listener) :
m_stdio_communication ("process.stdio"),
m_stdio_communication_mutex (Mutex::eMutexTypeRecursive),
m_stdout_data (),
m_memory_cache (),
m_memory_cache (*this),
m_allocated_memory_cache (*this),
m_next_event_action_ap()
{
UpdateInstanceName();
@@ -1759,7 +1622,7 @@ size_t
Process::ReadMemory (addr_t addr, void *buf, size_t size, Error &error)
{
// Memory caching enabled, no verification
return m_memory_cache.Read (this, addr, buf, size, error);
return m_memory_cache.Read (addr, buf, size, error);
}
#endif // #else for #if defined (VERIFY_MEMORY_READS)
@@ -1968,29 +1831,36 @@ Process::WriteMemory (addr_t addr, const void *buf, size_t size, Error &error)
return bytes_written;
}
#define USE_ALLOCATE_MEMORY_CACHE 1
addr_t
Process::AllocateMemory(size_t size, uint32_t permissions, Error &error)
{
// Fixme: we should track the blocks we've allocated, and clean them up...
// We could even do our own allocator here if that ends up being more efficient.
#if defined (USE_ALLOCATE_MEMORY_CACHE)
return m_allocated_memory_cache.AllocateMemory(size, permissions, error);
#else
addr_t allocated_addr = DoAllocateMemory (size, permissions, error);
LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
if (log)
log->Printf("Process::AllocateMemory(size=%4zu, permissions=%c%c%c) => 0x%16.16llx (m_stop_id = %u)",
log->Printf("Process::AllocateMemory(size=%4zu, permissions=%s) => 0x%16.16llx (m_stop_id = %u)",
size,
permissions & ePermissionsReadable ? 'r' : '-',
permissions & ePermissionsWritable ? 'w' : '-',
permissions & ePermissionsExecutable ? 'x' : '-',
GetPermissionsAsCString (permissions),
(uint64_t)allocated_addr,
m_stop_id);
return allocated_addr;
#endif
}
Error
Process::DeallocateMemory (addr_t ptr)
{
Error error(DoDeallocateMemory (ptr));
Error error;
#if defined (USE_ALLOCATE_MEMORY_CACHE)
if (!m_allocated_memory_cache.DeallocateMemory(ptr))
{
error.SetErrorStringWithFormat ("deallocation of memory at 0x%llx failed.", (uint64_t)ptr);
}
#else
error = DoDeallocateMemory (ptr);
LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
if (log)
@@ -1998,6 +1868,7 @@ Process::DeallocateMemory (addr_t ptr)
ptr,
error.AsCString("SUCCESS"),
m_stop_id);
#endif
return error;
}