diff options
Diffstat (limited to 'deps/jemalloc/src/pages.c')
| -rw-r--r-- | deps/jemalloc/src/pages.c | 177 |
1 files changed, 24 insertions, 153 deletions
diff --git a/deps/jemalloc/src/pages.c b/deps/jemalloc/src/pages.c index 5f0c9669d..83a167f67 100644 --- a/deps/jemalloc/src/pages.c +++ b/deps/jemalloc/src/pages.c @@ -1,49 +1,29 @@ #define JEMALLOC_PAGES_C_ #include "jemalloc/internal/jemalloc_internal.h" -#ifdef JEMALLOC_SYSCTL_VM_OVERCOMMIT -#include <sys/sysctl.h> -#endif - -/******************************************************************************/ -/* Data. */ - -#ifndef _WIN32 -# define PAGES_PROT_COMMIT (PROT_READ | PROT_WRITE) -# define PAGES_PROT_DECOMMIT (PROT_NONE) -static int mmap_flags; -#endif -static bool os_overcommits; - /******************************************************************************/ void * -pages_map(void *addr, size_t size, bool *commit) +pages_map(void *addr, size_t size) { void *ret; assert(size != 0); - if (os_overcommits) - *commit = true; - #ifdef _WIN32 /* * If VirtualAlloc can't allocate at the given address when one is * given, it fails and returns NULL. */ - ret = VirtualAlloc(addr, size, MEM_RESERVE | (*commit ? MEM_COMMIT : 0), + ret = VirtualAlloc(addr, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE); #else /* * We don't use MAP_FIXED here, because it can cause the *replacement* * of existing mappings, and we only want to create new mappings. */ - { - int prot = *commit ? PAGES_PROT_COMMIT : PAGES_PROT_DECOMMIT; - - ret = mmap(addr, size, prot, mmap_flags, -1, 0); - } + ret = mmap(addr, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, + -1, 0); assert(ret != NULL); if (ret == MAP_FAILED) @@ -87,8 +67,7 @@ pages_unmap(void *addr, size_t size) } void * -pages_trim(void *addr, size_t alloc_size, size_t leadsize, size_t size, - bool *commit) +pages_trim(void *addr, size_t alloc_size, size_t leadsize, size_t size) { void *ret = (void *)((uintptr_t)addr + leadsize); @@ -98,7 +77,7 @@ pages_trim(void *addr, size_t alloc_size, size_t leadsize, size_t size, void *new_addr; pages_unmap(addr, alloc_size); - new_addr = pages_map(ret, size, commit); + new_addr = pages_map(ret, size); if (new_addr == ret) return (ret); if (new_addr) @@ -122,17 +101,17 @@ static bool pages_commit_impl(void *addr, size_t size, bool commit) { - if (os_overcommits) - return (true); - -#ifdef _WIN32 - return (commit ? (addr != VirtualAlloc(addr, size, MEM_COMMIT, - PAGE_READWRITE)) : (!VirtualFree(addr, size, MEM_DECOMMIT))); -#else - { - int prot = commit ? PAGES_PROT_COMMIT : PAGES_PROT_DECOMMIT; - void *result = mmap(addr, size, prot, mmap_flags | MAP_FIXED, - -1, 0); +#ifndef _WIN32 + /* + * The following decommit/commit implementation is functional, but + * always disabled because it doesn't add value beyong improved + * debugging (at the cost of extra system calls) on systems that + * overcommit. + */ + if (false) { + int prot = commit ? (PROT_READ | PROT_WRITE) : PROT_NONE; + void *result = mmap(addr, size, prot, MAP_PRIVATE | MAP_ANON | + MAP_FIXED, -1, 0); if (result == MAP_FAILED) return (true); if (result != addr) { @@ -146,6 +125,7 @@ pages_commit_impl(void *addr, size_t size, bool commit) return (false); } #endif + return (true); } bool @@ -170,16 +150,15 @@ pages_purge(void *addr, size_t size) #ifdef _WIN32 VirtualAlloc(addr, size, MEM_RESET, PAGE_READWRITE); unzeroed = true; -#elif (defined(JEMALLOC_PURGE_MADVISE_FREE) || \ - defined(JEMALLOC_PURGE_MADVISE_DONTNEED)) -# if defined(JEMALLOC_PURGE_MADVISE_FREE) -# define JEMALLOC_MADV_PURGE MADV_FREE -# define JEMALLOC_MADV_ZEROS false -# elif defined(JEMALLOC_PURGE_MADVISE_DONTNEED) +#elif defined(JEMALLOC_HAVE_MADVISE) +# ifdef JEMALLOC_PURGE_MADVISE_DONTNEED # define JEMALLOC_MADV_PURGE MADV_DONTNEED # define JEMALLOC_MADV_ZEROS true +# elif defined(JEMALLOC_PURGE_MADVISE_FREE) +# define JEMALLOC_MADV_PURGE MADV_FREE +# define JEMALLOC_MADV_ZEROS false # else -# error No madvise(2) flag defined for purging unused dirty pages +# error "No madvise(2) flag defined for purging unused dirty pages." # endif int err = madvise(addr, size, JEMALLOC_MADV_PURGE); unzeroed = (!JEMALLOC_MADV_ZEROS || err != 0); @@ -192,111 +171,3 @@ pages_purge(void *addr, size_t size) return (unzeroed); } -bool -pages_huge(void *addr, size_t size) -{ - - assert(PAGE_ADDR2BASE(addr) == addr); - assert(PAGE_CEILING(size) == size); - -#ifdef JEMALLOC_THP - return (madvise(addr, size, MADV_HUGEPAGE) != 0); -#else - return (false); -#endif -} - -bool -pages_nohuge(void *addr, size_t size) -{ - - assert(PAGE_ADDR2BASE(addr) == addr); - assert(PAGE_CEILING(size) == size); - -#ifdef JEMALLOC_THP - return (madvise(addr, size, MADV_NOHUGEPAGE) != 0); -#else - return (false); -#endif -} - -#ifdef JEMALLOC_SYSCTL_VM_OVERCOMMIT -static bool -os_overcommits_sysctl(void) -{ - int vm_overcommit; - size_t sz; - - sz = sizeof(vm_overcommit); - if (sysctlbyname("vm.overcommit", &vm_overcommit, &sz, NULL, 0) != 0) - return (false); /* Error. */ - - return ((vm_overcommit & 0x3) == 0); -} -#endif - -#ifdef JEMALLOC_PROC_SYS_VM_OVERCOMMIT_MEMORY -/* - * Use syscall(2) rather than {open,read,close}(2) when possible to avoid - * reentry during bootstrapping if another library has interposed system call - * wrappers. - */ -static bool -os_overcommits_proc(void) -{ - int fd; - char buf[1]; - ssize_t nread; - -#if defined(JEMALLOC_USE_SYSCALL) && defined(SYS_open) - fd = (int)syscall(SYS_open, "/proc/sys/vm/overcommit_memory", O_RDONLY); -#else - fd = open("/proc/sys/vm/overcommit_memory", O_RDONLY); -#endif - if (fd == -1) - return (false); /* Error. */ - -#if defined(JEMALLOC_USE_SYSCALL) && defined(SYS_read) - nread = (ssize_t)syscall(SYS_read, fd, &buf, sizeof(buf)); -#else - nread = read(fd, &buf, sizeof(buf)); -#endif - -#if defined(JEMALLOC_USE_SYSCALL) && defined(SYS_close) - syscall(SYS_close, fd); -#else - close(fd); -#endif - - if (nread < 1) - return (false); /* Error. */ - /* - * /proc/sys/vm/overcommit_memory meanings: - * 0: Heuristic overcommit. - * 1: Always overcommit. - * 2: Never overcommit. - */ - return (buf[0] == '0' || buf[0] == '1'); -} -#endif - -void -pages_boot(void) -{ - -#ifndef _WIN32 - mmap_flags = MAP_PRIVATE | MAP_ANON; -#endif - -#ifdef JEMALLOC_SYSCTL_VM_OVERCOMMIT - os_overcommits = os_overcommits_sysctl(); -#elif defined(JEMALLOC_PROC_SYS_VM_OVERCOMMIT_MEMORY) - os_overcommits = os_overcommits_proc(); -# ifdef MAP_NORESERVE - if (os_overcommits) - mmap_flags |= MAP_NORESERVE; -# endif -#else - os_overcommits = false; -#endif -} |