diff options
Diffstat (limited to 'src/mem/physical.cc')
| -rw-r--r-- | src/mem/physical.cc | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/src/mem/physical.cc b/src/mem/physical.cc index b5627cfa2..e6d682624 100644 --- a/src/mem/physical.cc +++ b/src/mem/physical.cc @@ -56,12 +56,29 @@ #include "mem/abstract_mem.hh" #include "mem/physical.hh" +/** + * On Linux, MAP_NORESERVE allow us to simulate a very large memory + * without committing to actually providing the swap space on the + * host. On OSX the MAP_NORESERVE flag does not exist, so simply make + * it 0. + */ +#if defined(__APPLE__) +#ifndef MAP_NORESERVE +#define MAP_NORESERVE 0 +#endif +#endif + using namespace std; PhysicalMemory::PhysicalMemory(const string& _name, - const vector<AbstractMemory*>& _memories) : - _name(_name), rangeCache(addrMap.end()), size(0) + const vector<AbstractMemory*>& _memories, + bool mmap_using_noreserve) : + _name(_name), rangeCache(addrMap.end()), size(0), + mmapUsingNoReserve(mmap_using_noreserve) { + if (mmap_using_noreserve) + warn("Not reserving swap space. May cause SIGSEGV on actual usage\n"); + // add the memories from the system to the address map as // appropriate for (const auto& m : _memories) { @@ -148,6 +165,13 @@ PhysicalMemory::createBackingStore(AddrRange range, DPRINTF(AddrRanges, "Creating backing store for range %s with size %d\n", range.to_string(), range.size()); int map_flags = MAP_ANON | MAP_PRIVATE; + + // to be able to simulate very large memories, the user can opt to + // pass noreserve to mmap + if (mmapUsingNoReserve) { + map_flags |= MAP_NORESERVE; + } + uint8_t* pmem = (uint8_t*) mmap(NULL, range.size(), PROT_READ | PROT_WRITE, map_flags, -1, 0); |