diff -r b7bcf7497f93 -r e6d4971c8650 hotspot/src/os/linux/vm/os_linux.cpp --- a/hotspot/src/os/linux/vm/os_linux.cpp Mon Jun 10 11:30:51 2013 +0200 +++ b/hotspot/src/os/linux/vm/os_linux.cpp Thu Jun 13 11:16:38 2013 -0700 @@ -2612,11 +2612,49 @@ } } +static bool recoverable_mmap_error(int err) { + // See if the error is one we can let the caller handle. This + // list of errno values comes from JBS-6843484. I can't find a + // Linux man page that documents this specific set of errno + // values so while this list currently matches Solaris, it may + // change as we gain experience with this failure mode. + switch (err) { + case EBADF: + case EINVAL: + case ENOTSUP: + // let the caller deal with these errors + return true; + + default: + // Any remaining errors on this OS can cause our reserved mapping + // to be lost. That can cause confusion where different data + // structures think they have the same memory mapped. The worst + // scenario is if both the VM and a library think they have the + // same memory mapped. + return false; + } +} + +static void warn_fail_commit_memory(char* addr, size_t size, bool exec, + int err) { + warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT + ", %d) failed; error='%s' (errno=%d)", addr, size, exec, + strerror(err), err); +} + +static void warn_fail_commit_memory(char* addr, size_t size, + size_t alignment_hint, bool exec, + int err) { + warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT + ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", addr, size, + alignment_hint, exec, strerror(err), err); +} + // NOTE: Linux kernel does not really reserve the pages for us. // All it does is to check if there are enough free pages // left at the time of mmap(). This could be a potential // problem. -bool os::pd_commit_memory(char* addr, size_t size, bool exec) { +int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) { int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); @@ -2624,9 +2662,32 @@ if (UseNUMAInterleaving) { numa_make_global(addr, size); } - return true; - } - return false; + return 0; + } + + int err = errno; // save errno from mmap() call above + + if (!recoverable_mmap_error(err)) { + warn_fail_commit_memory(addr, size, exec, err); + vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory."); + } + + return err; +} + +bool os::pd_commit_memory(char* addr, size_t size, bool exec) { + return os::Linux::commit_memory_impl(addr, size, exec) == 0; +} + +void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, + const char* mesg) { + assert(mesg != NULL, "mesg must be specified"); + int err = os::Linux::commit_memory_impl(addr, size, exec); + if (err != 0) { + // the caller wants all commit errors to exit with the specified mesg: + warn_fail_commit_memory(addr, size, exec, err); + vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); + } } // Define MAP_HUGETLB here so we can build HotSpot on old systems. @@ -2639,8 +2700,9 @@ #define MADV_HUGEPAGE 14 #endif -bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, - bool exec) { +int os::Linux::commit_memory_impl(char* addr, size_t size, + size_t alignment_hint, bool exec) { + int err; if (UseHugeTLBFS && alignment_hint > (size_t)vm_page_size()) { int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; uintptr_t res = @@ -2651,16 +2713,46 @@ if (UseNUMAInterleaving) { numa_make_global(addr, size); } - return true; + return 0; + } + + err = errno; // save errno from mmap() call above + + if (!recoverable_mmap_error(err)) { + // However, it is not clear that this loss of our reserved mapping + // happens with large pages on Linux or that we cannot recover + // from the loss. For now, we just issue a warning and we don't + // call vm_exit_out_of_memory(). This issue is being tracked by + // JBS-8007074. + warn_fail_commit_memory(addr, size, alignment_hint, exec, err); +// vm_exit_out_of_memory(size, OOM_MMAP_ERROR, +// "committing reserved memory."); } // Fall through and try to use small pages } - if (commit_memory(addr, size, exec)) { + err = os::Linux::commit_memory_impl(addr, size, exec); + if (err == 0) { realign_memory(addr, size, alignment_hint); - return true; - } - return false; + } + return err; +} + +bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, + bool exec) { + return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0; +} + +void os::pd_commit_memory_or_exit(char* addr, size_t size, + size_t alignment_hint, bool exec, + const char* mesg) { + assert(mesg != NULL, "mesg must be specified"); + int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec); + if (err != 0) { + // the caller wants all commit errors to exit with the specified mesg: + warn_fail_commit_memory(addr, size, alignment_hint, exec, err); + vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg); + } } void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { @@ -2678,7 +2770,7 @@ // small pages on top of the SHM segment. This method always works for small pages, so we // allow that in any case. if (alignment_hint <= (size_t)os::vm_page_size() || !UseSHM) { - commit_memory(addr, bytes, alignment_hint, false); + commit_memory(addr, bytes, alignment_hint, !ExecMem); } } @@ -2931,7 +3023,7 @@ ::munmap((void*)stack_extent, (uintptr_t)addr - stack_extent); } - return os::commit_memory(addr, size); + return os::commit_memory(addr, size, !ExecMem); } // If this is a growable mapping, remove the guard pages entirely by @@ -3053,7 +3145,7 @@ MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, -1, 0); - if (p != (void *) -1) { + if (p != MAP_FAILED) { // We don't know if this really is a huge page or not. FILE *fp = fopen("/proc/self/maps", "r"); if (fp) { @@ -4393,7 +4485,7 @@ if (!UseMembar) { address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); - guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page"); + guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); os::set_memory_serialize_page( mem_serialize_page ); #ifndef PRODUCT