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-rw-r--r--source/l/gc/noelision.patch127
1 files changed, 127 insertions, 0 deletions
diff --git a/source/l/gc/noelision.patch b/source/l/gc/noelision.patch
new file mode 100644
index 00000000..0e1515ea
--- /dev/null
+++ b/source/l/gc/noelision.patch
@@ -0,0 +1,127 @@
+diff --git c/include/private/gc_priv.h w/include/private/gc_priv.h
+index 0ad92fc..b877fac 100644
+--- c/include/private/gc_priv.h
++++ w/include/private/gc_priv.h
+@@ -2368,6 +2368,7 @@ GC_INNER ptr_t GC_store_debug_info(ptr_t p, word sz, const char *str,
+ /* GC_notify_all_builder() is called when GC_fl_builder_count */
+ /* reaches 0. */
+
++ GC_INNER void GC_setup_mark_lock(void);
+ GC_INNER void GC_acquire_mark_lock(void);
+ GC_INNER void GC_release_mark_lock(void);
+ GC_INNER void GC_notify_all_builder(void);
+diff --git c/include/private/gcconfig.h w/include/private/gcconfig.h
+index c753cc2..b5ed075 100644
+--- c/include/private/gcconfig.h
++++ w/include/private/gcconfig.h
+@@ -1357,6 +1357,11 @@
+ # define PREFETCH_FOR_WRITE(x) \
+ __asm__ __volatile__ ("prefetchw %0" : : "m"(*(char *)(x)))
+ # endif
++# if defined(__GLIBC__)
++ /* Workaround lock elision implementation for some glibc. */
++# define GLIBC_2_19_TSX_BUG
++# include <gnu/libc-version.h> /* for gnu_get_libc_version() */
++# endif
+ # endif
+ # ifdef CYGWIN32
+ # define OS_TYPE "CYGWIN32"
+@@ -2257,6 +2262,11 @@
+ /* FIXME: This seems to be fixed in GLibc v2.14. */
+ # define GETCONTEXT_FPU_EXCMASK_BUG
+ # endif
++# if defined(__GLIBC__)
++ /* Workaround lock elision implementation for some glibc. */
++# define GLIBC_2_19_TSX_BUG
++# include <gnu/libc-version.h> /* for gnu_get_libc_version() */
++# endif
+ # endif
+ # ifdef DARWIN
+ # define OS_TYPE "DARWIN"
+diff --git c/include/private/pthread_support.h w/include/private/pthread_support.h
+index 525a9aa..017f194 100644
+--- c/include/private/pthread_support.h
++++ w/include/private/pthread_support.h
+@@ -148,6 +148,8 @@ GC_INNER_PTHRSTART GC_thread GC_start_rtn_prepare_thread(
+ struct GC_stack_base *sb, void *arg);
+ GC_INNER_PTHRSTART void GC_thread_exit_proc(void *);
+
++GC_INNER void GC_setup_mark_lock(void);
++
+ #endif /* GC_PTHREADS && !GC_WIN32_THREADS */
+
+ #endif /* GC_PTHREAD_SUPPORT_H */
+diff --git c/misc.c w/misc.c
+index df434a1..3aca41d 100644
+--- c/misc.c
++++ w/misc.c
+@@ -875,6 +875,9 @@ GC_API void GC_CALL GC_init(void)
+ /* else */ InitializeCriticalSection (&GC_allocate_ml);
+ }
+ # endif /* GC_WIN32_THREADS */
++# if defined(GC_PTHREADS) && !defined(GC_WIN32_THREADS)
++ GC_setup_mark_lock();
++# endif /* GC_PTHREADS */
+ # if (defined(MSWIN32) || defined(MSWINCE)) && defined(THREADS)
+ InitializeCriticalSection(&GC_write_cs);
+ # endif
+diff --git c/pthread_support.c w/pthread_support.c
+index c00b93d..8a7c50b 100644
+--- c/pthread_support.c
++++ w/pthread_support.c
+@@ -1979,6 +1979,55 @@ GC_INNER void GC_lock(void)
+
+ static pthread_cond_t builder_cv = PTHREAD_COND_INITIALIZER;
+
++#ifdef GLIBC_2_19_TSX_BUG
++ /* Parse string like <major>[.<minor>[<tail>]] and return major value. */
++ static int parse_version(int *pminor, const char *pverstr) {
++ char *endp;
++ unsigned long value = strtoul(pverstr, &endp, 10);
++ int major = (int)value;
++
++ if (major < 0 || (char *)pverstr == endp || (unsigned)major != value) {
++ /* Parse error */
++ return -1;
++ }
++ if (*endp != '.') {
++ /* No minor part. */
++ *pminor = -1;
++ } else {
++ value = strtoul(endp + 1, &endp, 10);
++ *pminor = (int)value;
++ if (*pminor < 0 || (unsigned)(*pminor) != value) {
++ return -1;
++ }
++ }
++ return major;
++ }
++#endif /* GLIBC_2_19_TSX_BUG */
++
++GC_INNER void GC_setup_mark_lock(void)
++{
++# ifdef GLIBC_2_19_TSX_BUG
++ pthread_mutexattr_t mattr;
++ int glibc_minor = -1;
++ int glibc_major = parse_version(&glibc_minor, gnu_get_libc_version());
++
++ if (glibc_major > 2 || (glibc_major == 2 && glibc_minor >= 19)) {
++ /* TODO: disable this workaround for glibc with fixed TSX */
++ /* This disables lock elision to workaround a bug in glibc 2.19+ */
++ if (0 != pthread_mutexattr_init(&mattr)) {
++ ABORT("pthread_mutexattr_init failed");
++ }
++ if (0 != pthread_mutexattr_settype(&mattr, PTHREAD_MUTEX_NORMAL)) {
++ ABORT("pthread_mutexattr_settype failed");
++ }
++ if (0 != pthread_mutex_init(&mark_mutex, &mattr)) {
++ ABORT("pthread_mutex_init failed");
++ }
++ pthread_mutexattr_destroy(&mattr);
++ }
++# endif
++}
++
+ GC_INNER void GC_acquire_mark_lock(void)
+ {
+ GC_ASSERT(GC_mark_lock_holder != NUMERIC_THREAD_ID(pthread_self()));