From 4d4ba58fca7753c1bbe56d43e7977f2a9601e772 Mon Sep 17 00:00:00 2001 From: "Bjoern B. Brandenburg" Date: Thu, 28 Jul 2011 01:16:04 -0400 Subject: Switch to new np-section protocol. Everything is in one 32-bit word now. --- src/kernel_iface.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/kernel_iface.c b/src/kernel_iface.c index 1426795..33d56df 100644 --- a/src/kernel_iface.c +++ b/src/kernel_iface.c @@ -43,6 +43,8 @@ int init_kernel_iface(void) int err = 0; long page_size = sysconf(_SC_PAGESIZE); + BUILD_BUG_ON(sizeof(union np_flag) != sizeof(uint32_t)); + err = map_file(LITMUS_CTRL_DEVICE, (void**) &ctrl_page, CTRL_PAGES * page_size); if (err) { fprintf(stderr, "%s: cannot open LITMUS^RT control page (%m)\n", @@ -55,7 +57,7 @@ int init_kernel_iface(void) void enter_np(void) { if (likely(ctrl_page != NULL) || init_kernel_iface() == 0) - ctrl_page->np_flag++; + ctrl_page->sched.np.flag++; else fprintf(stderr, "enter_np: control page not mapped!\n"); } @@ -63,14 +65,21 @@ void enter_np(void) void exit_np(void) { - if (likely(ctrl_page != NULL) && --ctrl_page->np_flag == 0) { + if (likely(ctrl_page != NULL) && + ctrl_page->sched.np.flag && + !(--ctrl_page->sched.np.flag)) { /* became preemptive, let's check for delayed preemptions */ __sync_synchronize(); - if (ctrl_page->delayed_preemption) + if (ctrl_page->sched.np.preempt) sched_yield(); } } +int requested_to_preempt(void) +{ + return (likely(ctrl_page != NULL) && ctrl_page->sched.np.preempt); +} + /* init and return a ptr to the control page for * preemption and migration overhead analysis * -- cgit v1.2.2