[Python-checkins] cpython: Better resolution for issue #11849: Ensure that free()d memory arenas are
antoine.pitrou
python-checkins at python.org
Sat Nov 26 01:23:41 CET 2011
http://hg.python.org/cpython/rev/e7aa72e6aad4
changeset: 73747:e7aa72e6aad4
parent: 73732:736b0aec412b
user: Antoine Pitrou <solipsis at pitrou.net>
date: Sat Nov 26 01:11:02 2011 +0100
summary:
Better resolution for issue #11849: Ensure that free()d memory arenas are really released
on POSIX systems supporting anonymous memory mappings. Patch by Charles-François Natali.
files:
Misc/NEWS | 8 +++---
Objects/obmalloc.c | 37 ++++++++++++++++++++-------------
configure | 36 +++-----------------------------
configure.in | 13 +----------
pyconfig.h.in | 6 ++--
5 files changed, 35 insertions(+), 65 deletions(-)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
Core and Builtins
-----------------
+- Issue #11849: Ensure that free()d memory arenas are really released
+ on POSIX systems supporting anonymous memory mappings. Patch by
+ Charles-François Natali.
+
- Issue #13436: Fix a bogus error message when an AST object was passed
an invalid integer value.
@@ -260,10 +264,6 @@
interpreter is shutting down; instead, these threads are now killed when
they try to take the GIL.
-- Issue #11849: Make it more likely for the system allocator to release
- free()d memory arenas on glibc-based systems. Patch by Charles-François
- Natali.
-
- Issue #9756: When calling a method descriptor or a slot wrapper descriptor,
the check of the object type doesn't read the __class__ attribute anymore.
Fix a crash if a class override its __class__ attribute (e.g. a proxy of the
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -2,8 +2,11 @@
#ifdef WITH_PYMALLOC
-#ifdef HAVE_MALLOPT_MMAP_THRESHOLD
- #include <malloc.h>
+#ifdef HAVE_MMAP
+ #include <sys/mman.h>
+ #ifdef MAP_ANONYMOUS
+ #define ARENAS_USE_MMAP
+ #endif
#endif
#ifdef WITH_VALGRIND
@@ -183,15 +186,15 @@
/*
* The allocator sub-allocates <Big> blocks of memory (called arenas) aligned
* on a page boundary. This is a reserved virtual address space for the
- * current process (obtained through a malloc call). In no way this means
- * that the memory arenas will be used entirely. A malloc(<Big>) is usually
- * an address range reservation for <Big> bytes, unless all pages within this
- * space are referenced subsequently. So malloc'ing big blocks and not using
- * them does not mean "wasting memory". It's an addressable range wastage...
+ * current process (obtained through a malloc()/mmap() call). In no way this
+ * means that the memory arenas will be used entirely. A malloc(<Big>) is
+ * usually an address range reservation for <Big> bytes, unless all pages within
+ * this space are referenced subsequently. So malloc'ing big blocks and not
+ * using them does not mean "wasting memory". It's an addressable range
+ * wastage...
*
- * Therefore, allocating arenas with malloc is not optimal, because there is
- * some address space wastage, but this is the most portable way to request
- * memory from the system across various platforms.
+ * Arenas are allocated with mmap() on systems supporting anonymous memory
+ * mappings to reduce heap fragmentation.
*/
#define ARENA_SIZE (256 << 10) /* 256KB */
@@ -557,11 +560,6 @@
if (numarenas > PY_SIZE_MAX / sizeof(*arenas))
return NULL; /* overflow */
#endif
-#ifdef HAVE_MALLOPT_MMAP_THRESHOLD
- /* Ensure arenas are allocated by mmap to avoid heap fragmentation. */
- if (numarenas == INITIAL_ARENA_OBJECTS)
- mallopt(M_MMAP_THRESHOLD, ARENA_SIZE);
-#endif
nbytes = numarenas * sizeof(*arenas);
arenaobj = (struct arena_object *)realloc(arenas, nbytes);
if (arenaobj == NULL)
@@ -594,7 +592,12 @@
arenaobj = unused_arena_objects;
unused_arena_objects = arenaobj->nextarena;
assert(arenaobj->address == 0);
+#ifdef ARENAS_USE_MMAP
+ arenaobj->address = (uptr)mmap(NULL, ARENA_SIZE, PROT_READ|PROT_WRITE,
+ MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+#else
arenaobj->address = (uptr)malloc(ARENA_SIZE);
+#endif
if (arenaobj->address == 0) {
/* The allocation failed: return NULL after putting the
* arenaobj back.
@@ -1071,7 +1074,11 @@
unused_arena_objects = ao;
/* Free the entire arena. */
+#ifdef ARENAS_USE_MMAP
+ munmap((void *)ao->address, ARENA_SIZE);
+#else
free((void *)ao->address);
+#endif
ao->address = 0; /* mark unassociated */
--narenas_currently_allocated;
diff --git a/configure b/configure
--- a/configure
+++ b/configure
@@ -9401,8 +9401,8 @@
getgrouplist getgroups getlogin getloadavg getpeername getpgid getpid \
getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
if_nameindex \
- initgroups kill killpg lchmod lchown lockf linkat lstat lutimes memrchr \
- mbrtowc mkdirat mkfifo \
+ initgroups kill killpg lchmod lchown lockf linkat lstat lutimes mmap \
+ memrchr mbrtowc mkdirat mkfifo \
mkfifoat mknod mknodat mktime mremap nice openat pathconf pause pipe2 plock poll \
posix_fallocate posix_fadvise pread \
pthread_init pthread_kill putenv pwrite readlink readlinkat readv realpath renameat \
@@ -9784,34 +9784,6 @@
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether mallopt can set malloc mmap threshold" >&5
-$as_echo_n "checking whether mallopt can set malloc mmap threshold... " >&6; }
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h. */
-
-#include <malloc.h>
-
-int
-main ()
-{
-mallopt(M_MMAP_THRESHOLD, 256 * 1024)
- ;
- return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-
-$as_echo "#define HAVE_MALLOPT_MMAP_THRESHOLD 1" >>confdefs.h
-
- { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-else
- { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for broken unsetenv" >&5
$as_echo_n "checking for broken unsetenv... " >&6; }
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
@@ -14591,8 +14563,8 @@
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
# Files that config.status was made for.
-config_files="$ac_config_files"
-config_headers="$ac_config_headers"
+config_files="`echo $ac_config_files`"
+config_headers="`echo $ac_config_headers`"
_ACEOF
diff --git a/configure.in b/configure.in
--- a/configure.in
+++ b/configure.in
@@ -2567,8 +2567,8 @@
getgrouplist getgroups getlogin getloadavg getpeername getpgid getpid \
getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
if_nameindex \
- initgroups kill killpg lchmod lchown lockf linkat lstat lutimes memrchr \
- mbrtowc mkdirat mkfifo \
+ initgroups kill killpg lchmod lchown lockf linkat lstat lutimes mmap \
+ memrchr mbrtowc mkdirat mkfifo \
mkfifoat mknod mknodat mktime mremap nice openat pathconf pause pipe2 plock poll \
posix_fallocate posix_fadvise pread \
pthread_init pthread_kill putenv pwrite readlink readlinkat readv realpath renameat \
@@ -2679,15 +2679,6 @@
[AC_MSG_RESULT(no)
])
-AC_MSG_CHECKING(whether mallopt can set malloc mmap threshold)
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-#include <malloc.h>
-]], [[mallopt(M_MMAP_THRESHOLD, 256 * 1024)]])],
- [AC_DEFINE(HAVE_MALLOPT_MMAP_THRESHOLD, 1, Define if mallopt can set malloc mmap threshold.)
- AC_MSG_RESULT(yes)],
- [AC_MSG_RESULT(no)
-])
-
AC_MSG_CHECKING(for broken unsetenv)
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <stdlib.h>
diff --git a/pyconfig.h.in b/pyconfig.h.in
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -512,9 +512,6 @@
/* Define this if you have the makedev macro. */
#undef HAVE_MAKEDEV
-/* Define if mallopt can set malloc mmap threshold. */
-#undef HAVE_MALLOPT_MMAP_THRESHOLD
-
/* Define to 1 if you have the `mbrtowc' function. */
#undef HAVE_MBRTOWC
@@ -545,6 +542,9 @@
/* Define to 1 if you have the `mktime' function. */
#undef HAVE_MKTIME
+/* Define to 1 if you have the `mmap' function. */
+#undef HAVE_MMAP
+
/* Define to 1 if you have the `mremap' function. */
#undef HAVE_MREMAP
--
Repository URL: http://hg.python.org/cpython
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