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spin-wait based kernel timer (for futex() timeout) implementation

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Balazs Gerofi bgerofi@riken.jp
2012-11-28 15:22:53 +09:00
parent b59e36e1a5
commit 092069fd80
6 changed files with 121 additions and 19 deletions
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43
kernel/syscall.c
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@@ -846,8 +846,6 @@ SYSCALL_DECLARE(madvise)
SYSCALL_DECLARE(futex)
{
// TODO: timespec support!
//struct timespec _utime;
uint64_t timeout = 0; // No timeout
uint32_t val2 = 0;
@@ -857,20 +855,47 @@ SYSCALL_DECLARE(futex)
struct timespec *utime = (struct timespec*)aal_mc_syscall_arg3(ctx);
uint32_t *uaddr2 = (uint32_t *)aal_mc_syscall_arg4(ctx);
uint32_t val3 = (uint32_t)aal_mc_syscall_arg5(ctx);
dkprintf("futex,uaddr=%lx,op=%x, val=%x, utime=%lx, uaddr2=%lx, val3=%x, []=%x\n", (unsigned long)uaddr, op, val, utime, uaddr2, val3, *uaddr);
/* Mask off the FUTEX_PRIVATE_FLAG,
* assume all futexes are address space private */
op = (op & FUTEX_CMD_MASK);
#if 0
if (utime && (op == FUTEX_WAIT)) {
if (copy_from_user(&_utime, utime, sizeof(_utime)) != 0)
if (utime && (op == FUTEX_WAIT_BITSET || op == FUTEX_WAIT)) {
/* gettimeofday(&tv_now, NULL) from host */
struct syscall_request request AAL_DMA_ALIGN;
struct timeval tv_now;
request.number = 96;
unsigned long __phys;
dkprintf("futex,utime and FUTEX_WAIT_*, uaddr=%lx, []=%x\n", (unsigned long)uaddr, *uaddr);
if (aal_mc_pt_virt_to_phys(cpu_local_var(current)->vm->page_table,
(void *)&tv_now, &__phys)) {
return -EFAULT;
}
request.args[0] = __phys;
int r = do_syscall(&request, ctx);
if (r < 0) {
return -EFAULT;
if (!timespec_valid(&_utime))
return -EINVAL;
timeout = timespec_to_ns(_utime);
}
dkprintf("futex, FUTEX_WAIT_*, arg3 != NULL, pc=%lx\n", (unsigned long)aal_mc_syscall_pc(ctx));
dkprintf("now->tv_sec=%016ld,tv_nsec=%016ld\n", tv_now.tv_sec, tv_now.tv_usec * 1000);
dkprintf("utime->tv_sec=%016ld,tv_nsec=%016ld\n", utime->tv_sec, utime->tv_nsec);
long nsec_now = ((long)tv_now.tv_sec * 1000000000ULL) +
tv_now.tv_usec * 1000;
long nsec_timeout = ((long)utime->tv_sec * 1000000000ULL) +
utime->tv_nsec * 1;
long diff_nsec = nsec_timeout - nsec_now;
timeout = (diff_nsec / 1000) * 1100; // (usec * 1.1GHz)
}
#endif
/* Requeue parameter in 'utime' if op == FUTEX_CMP_REQUEUE.
* number of waiters to wake in 'utime' if op == FUTEX_WAKE_OP. */