From: Torge Matthies tmatthies@codeweavers.com
Uses the MEMBARRIER_CMD_PRIVATE_EXPEDITED membarrier command introduced in Linux 4.14. --- dlls/ntdll/unix/virtual.c | 49 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-)
diff --git a/dlls/ntdll/unix/virtual.c b/dlls/ntdll/unix/virtual.c index 5a2087997bd..15ac8053378 100644 --- a/dlls/ntdll/unix/virtual.c +++ b/dlls/ntdll/unix/virtual.c @@ -39,6 +39,9 @@ #ifdef HAVE_SYS_SYSINFO_H # include <sys/sysinfo.h> #endif +#ifdef HAVE_SYS_SYSCALL_H +# include <sys/syscall.h> +#endif #ifdef HAVE_SYS_SYSCTL_H # include <sys/sysctl.h> #endif @@ -214,10 +217,16 @@ struct range_entry static struct range_entry *free_ranges; static struct range_entry *free_ranges_end;
-#if defined(__linux__) && (defined(__i386__) || defined(__x86_64__)) +#ifdef __linux__ +#ifdef __NR_membarrier +static BOOL membarrier_exp_available; +static pthread_once_t membarrier_init_once = PTHREAD_ONCE_INIT; +#endif +#if defined(__i386__) || defined(__x86_64__) static void *dontneed_page; static pthread_mutex_t dontneed_page_mutex = PTHREAD_MUTEX_INITIALIZER; #endif +#endif
static inline BOOL is_beyond_limit( const void *addr, size_t size, const void *limit ) @@ -5025,6 +5034,42 @@ NTSTATUS WINAPI NtFlushInstructionCache( HANDLE handle, const void *addr, SIZE_T }
+#if defined(__linux__) && defined(__NR_membarrier) +#define MEMBARRIER_CMD_QUERY 0x00 +#define MEMBARRIER_CMD_PRIVATE_EXPEDITED 0x08 +#define MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED 0x10 + + +static int membarrier( int cmd, unsigned int flags, int cpu_id ) +{ + return syscall( __NR_membarrier, cmd, flags, cpu_id ); +} + + +static void membarrier_init( void ) +{ + static const int exp_required_cmds = + MEMBARRIER_CMD_PRIVATE_EXPEDITED | MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED; + int available_cmds = membarrier( MEMBARRIER_CMD_QUERY, 0, 0 ); + if (available_cmds == -1) + return; + if ((available_cmds & exp_required_cmds) == exp_required_cmds) + membarrier_exp_available = !membarrier( MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED, 0, 0 ); +} + + +static int try_exp_membarrier( void ) +{ + pthread_once(&membarrier_init_once, membarrier_init); + if (!membarrier_exp_available) + return 0; + return !membarrier( MEMBARRIER_CMD_PRIVATE_EXPEDITED, 0, 0 ); +} +#else +static int try_exp_membarrier( void ) { return 0; } +#endif + + #if defined(__linux__) && (defined(__i386__) || defined(__x86_64__)) static int try_madvise( void ) { @@ -5093,6 +5138,8 @@ static void do_apc_memorybarrier( void ) */ void WINAPI NtFlushProcessWriteBuffers(void) { + if (try_exp_membarrier()) + return; if (try_madvise()) return; do_apc_memorybarrier();