From 12e9b4faf68a1a02ebf5ad69c03ac10f170f14cb Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 11 Oct 2012 22:47:07 -0400 Subject: i386 vsyscall support (vdso-provided sysenter/syscall instruction based) this doubles the performance of the fastest syscalls on the atom I tested it on; improvement is reportedly much more dramatic on worst-case cpus. cannot be used for cancellable syscalls. --- arch/i386/syscall_arch.h | 73 +++++------------------------------------------- 1 file changed, 7 insertions(+), 66 deletions(-) (limited to 'arch') diff --git a/arch/i386/syscall_arch.h b/arch/i386/syscall_arch.h index dc9ad147..2d64b0b0 100644 --- a/arch/i386/syscall_arch.h +++ b/arch/i386/syscall_arch.h @@ -8,111 +8,52 @@ static inline long __syscall0(long n) { unsigned long __ret; - __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n) : "memory"); + __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n) : "memory"); return __ret; } -#ifndef __PIC__ - static inline long __syscall1(long n, long a1) { unsigned long __ret; - __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1) : "memory"); + __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n), "d"(a1) : "memory"); return __ret; } static inline long __syscall2(long n, long a1, long a2) { unsigned long __ret; - __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2) : "memory"); + __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2) : "memory"); return __ret; } static inline long __syscall3(long n, long a1, long a2, long a3) { unsigned long __ret; - __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3) : "memory"); + __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2), "D"(a3) : "memory"); return __ret; } static inline long __syscall4(long n, long a1, long a2, long a3, long a4) { unsigned long __ret; - __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4) : "memory"); + __asm__ __volatile__ ("call __vsyscall" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2), "D"(a3), "S"(a4) : "memory"); return __ret; } static inline long __syscall5(long n, long a1, long a2, long a3, long a4, long a5) { unsigned long __ret; - __asm__ __volatile__ ("int $128" : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5) : "memory"); + __asm__ __volatile__ ("push %6 ; call __vsyscall ; add $4,%%esp" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2), "D"(a3), "S"(a4), "g"(a5) : "memory"); return __ret; } static inline long __syscall6(long n, long a1, long a2, long a3, long a4, long a5, long a6) { unsigned long __ret; - __asm__ __volatile__ ("pushl %7 ; pushl %%ebp ; mov 4(%%esp),%%ebp ; int $128 ; popl %%ebp ; popl %%ecx" - : "=a"(__ret) : "a"(n), "b"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5), "g"(a6) : "memory"); - return __ret; -} - -#else - -static inline long __syscall1(long n, long a1) -{ - unsigned long __ret; - __asm__ __volatile__ ("xchg %2,%%ebx ; int $128 ; xchg %2,%%ebx" - : "=a"(__ret) : "a"(n), "d"(a1) : "memory"); - return __ret; -} - -static inline long __syscall2(long n, long a1, long a2) -{ - unsigned long __ret; - __asm__ __volatile__ ("xchg %2,%%ebx ; int $128 ; xchg %2,%%ebx" - : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2) : "memory"); - return __ret; -} - -static inline long __syscall3(long n, long a1, long a2, long a3) -{ - unsigned long __ret; - __asm__ __volatile__ ("xchg %2,%%ebx ; int $128 ; xchg %2,%%ebx" - : "=a"(__ret) : "a"(n), "S"(a1), "c"(a2), "d"(a3) : "memory"); + __asm__ __volatile__ ("push %6 ; call __vsyscall6 ; add $4,%%esp" : "=a"(__ret) : "a"(n), "d"(a1), "c"(a2), "D"(a3), "S"(a4), "g"((long[]){a5, a6}) : "memory"); return __ret; } -static inline long __syscall4(long n, long a1, long a2, long a3, long a4) -{ - unsigned long __ret; - __asm__ __volatile__ ("xchg %2,%%ebx ; int $128 ; xchg %2,%%ebx" - : "=a"(__ret) : "a"(n), "D"(a1), "c"(a2), "d"(a3), "S"(a4) : "memory"); - return __ret; -} - -#if 0 -static inline long __syscall5(long n, long a1, long a2, long a3, long a4, long a5) -{ - unsigned long __ret; - __asm__ __volatile__ ("pushl %2 ; pushl %%ebx ; mov 4(%%esp),%%ebx ; int $128 ; popl %%ebx ; popl %%ecx" - : "=a"(__ret) : "a"(n), "g"(a1), "c"(a2), "d"(a3), "S"(a4), "D"(a5) : "memory"); - return __ret; -} -#else -static inline long __syscall5(long n, long a1, long a2, long a3, long a4, long a5) -{ - return (__syscall)(n, a1, a2, a3, a4, a5); -} -#endif - -static inline long __syscall6(long n, long a1, long a2, long a3, long a4, long a5, long a6) -{ - return (__syscall)(n, a1, a2, a3, a4, a5, a6); -} - -#endif - #define __SC_socket 1 #define __SC_bind 2 -- cgit v1.2.1