Switch the UML clocksource from interval timers to posix interval timers and move to a monotonic timer.
This fixes suspend&resume related timer issues and improves network performance as TCP state machines are now fed with the correct time; also correct QoS and traffic shaping. Signed-off-by: Thomas Meyer <tho...@m3y3r.de> --- diff --git a/arch/um/Makefile b/arch/um/Makefile index e4b1a96..43ef190 100644 --- a/arch/um/Makefile +++ b/arch/um/Makefile @@ -130,7 +130,7 @@ export LDS_ELF_FORMAT := $(ELF_FORMAT) # The wrappers will select whether using "malloc" or the kernel allocator. LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc -LD_FLAGS_CMDLINE = $(foreach opt,$(LDFLAGS),-Wl,$(opt)) +LD_FLAGS_CMDLINE = $(foreach opt,$(LDFLAGS),-Wl,$(opt)) -lrt # Used by link-vmlinux.sh which has special support for um link export CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE) diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index 08eec0b..5949cae 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -219,7 +219,7 @@ extern int set_umid(char *name); extern char *get_umid(void); /* signal.c */ -extern void timer_init(void); +extern void timer_set_signal_handler(void); extern void set_sigstack(void *sig_stack, int size); extern void remove_sigstack(void); extern void set_handler(int sig); @@ -240,12 +240,16 @@ extern void um_early_printk(const char *s, unsigned int n); extern void os_fix_helper_signals(void); /* time.c */ -extern void idle_sleep(unsigned long long nsecs); -extern int set_interval(void); -extern int timer_one_shot(int ticks); -extern long long disable_timer(void); +extern void os_idle_sleep(unsigned long long nsecs); +extern int os_timer_create(void* timer); +extern int os_timer_set_interval(void* timer, void* its); +extern int os_timer_one_shot(int ticks); +extern long long os_timer_disable(void); +extern long os_timer_remain(void* timer); extern void uml_idle_timer(void); +extern long long os_persistent_clock_emulation(void); extern long long os_nsecs(void); +extern long long os_vnsecs(void); /* skas/mem.c */ extern long run_syscall_stub(struct mm_id * mm_idp, diff --git a/arch/um/include/shared/skas/stub-data.h b/arch/um/include/shared/skas/stub-data.h index f6ed92c..f98b9e2 100644 --- a/arch/um/include/shared/skas/stub-data.h +++ b/arch/um/include/shared/skas/stub-data.h @@ -6,12 +6,12 @@ #ifndef __STUB_DATA_H #define __STUB_DATA_H -#include <sys/time.h> +#include <time.h> struct stub_data { - long offset; + unsigned long offset; int fd; - struct itimerval timer; + struct itimerspec timer; long err; }; diff --git a/arch/um/include/shared/timer-internal.h b/arch/um/include/shared/timer-internal.h new file mode 100644 index 0000000..03e6f21 --- /dev/null +++ b/arch/um/include/shared/timer-internal.h @@ -0,0 +1,13 @@ +/* + * Copyright (C) 2012 - 2014 Cisco Systems + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#ifndef __TIMER_INTERNAL_H__ +#define __TIMER_INTERNAL_H__ + +#define TIMER_MULTIPLIER 256 +#define TIMER_MIN_DELTA 500 + +#endif diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index f17bca8..d0bbd01 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -27,6 +27,7 @@ #include <kern_util.h> #include <os.h> #include <skas.h> +#include <timer-internal.h> /* * This is a per-cpu array. A processor only modifies its entry and it only @@ -201,11 +202,8 @@ void initial_thread_cb(void (*proc)(void *), void *arg) void arch_cpu_idle(void) { - unsigned long long nsecs; - cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); - nsecs = disable_timer(); - idle_sleep(nsecs); + os_idle_sleep(UM_NSEC_PER_SEC / UM_HZ); local_irq_enable(); } diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c index 289771d..814ec8b 100644 --- a/arch/um/kernel/skas/clone.c +++ b/arch/um/kernel/skas/clone.c @@ -24,6 +24,7 @@ void __attribute__ ((__section__ (".__syscall_stub"))) stub_clone_handler(void) { struct stub_data *data = (struct stub_data *) STUB_DATA; + timer_t timerid; long err; err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD, @@ -35,8 +36,14 @@ stub_clone_handler(void) if (err) goto out; - err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL, - (long) &data->timer, 0); + /* create posix interval timer */ + err = stub_syscall3(__NR_timer_create, CLOCK_MONOTONIC, 0l, (long) &timerid); + if (err) + goto out; + + /* set interval to the given value from copy_context_skas0() */ + err = stub_syscall4(__NR_timer_settime, (long) timerid, 0l, + (long) &data->timer, 0l); if (err) goto out; diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c index 117568d..d15966c 100644 --- a/arch/um/kernel/time.c +++ b/arch/um/kernel/time.c @@ -1,4 +1,5 @@ /* + * Copyright (C) 2012-2014 Cisco Systems * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Licensed under the GPL */ @@ -8,10 +9,12 @@ #include <linux/interrupt.h> #include <linux/jiffies.h> #include <linux/threads.h> +#include <linux/spinlock.h> #include <asm/irq.h> #include <asm/param.h> #include <kern_util.h> #include <os.h> +#include <timer-internal.h> void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) { @@ -22,18 +25,20 @@ void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) local_irq_restore(flags); } -static void itimer_set_mode(enum clock_event_mode mode, +static void timer_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) { switch (mode) { case CLOCK_EVT_MODE_PERIODIC: - set_interval(); + os_timer_set_interval(NULL, NULL); break; + case CLOCK_EVT_MODE_ONESHOT: + os_timer_one_shot(1); + case CLOCK_EVT_MODE_SHUTDOWN: case CLOCK_EVT_MODE_UNUSED: - case CLOCK_EVT_MODE_ONESHOT: - disable_timer(); + os_timer_disable(); break; case CLOCK_EVT_MODE_RESUME: @@ -41,68 +46,74 @@ static void itimer_set_mode(enum clock_event_mode mode, } } -static int itimer_next_event(unsigned long delta, +static int timer_next_event(unsigned long delta, struct clock_event_device *evt) { - return timer_one_shot(delta + 1); + return os_timer_one_shot(delta); } -static struct clock_event_device itimer_clockevent = { - .name = "itimer", +static struct clock_event_device timer_clockevent = { + .name = "posix-timer", .rating = 250, .cpumask = cpu_all_mask, .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, - .set_mode = itimer_set_mode, - .set_next_event = itimer_next_event, - .shift = 32, + .set_mode = timer_set_mode, + .set_next_event = timer_next_event, + .shift = 0, + .max_delta_ns = 0xffffffff, + .min_delta_ns = TIMER_MIN_DELTA, //microsecond resolution should be enough for anyone, same as 640K RAM .irq = 0, + .mult = 1, }; -static irqreturn_t um_timer(int irq, void *dev) +static irqreturn_t um_timer_irq(int irq, void *dev) { - (*itimer_clockevent.event_handler)(&itimer_clockevent); + (*timer_clockevent.event_handler)(&timer_clockevent); return IRQ_HANDLED; } -static cycle_t itimer_read(struct clocksource *cs) +static cycle_t timer_read(struct clocksource *cs) { - return os_nsecs() / 1000; + return os_nsecs() / TIMER_MULTIPLIER; } -static struct clocksource itimer_clocksource = { - .name = "itimer", +static struct clocksource timer_clocksource = { + .name = "timer", .rating = 300, - .read = itimer_read, + .read = timer_read, .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; -static void __init setup_itimer(void) +static void __init timer_setup(void) { int err; - err = request_irq(TIMER_IRQ, um_timer, 0, "timer", NULL); - if (err != 0) + err = request_irq(TIMER_IRQ, um_timer_irq, IRQF_TIMER, "hr timer", NULL); + if (err != 0) { printk(KERN_ERR "register_timer : request_irq failed - " "errno = %d\n", -err); + return; + } + + err = os_timer_create(NULL); + if (err != 0) { + printk(KERN_ERR "creation of timer failed - errno = %d\n", -err); + return; + } - itimer_clockevent.mult = div_sc(HZ, NSEC_PER_SEC, 32); - itimer_clockevent.max_delta_ns = - clockevent_delta2ns(60 * HZ, &itimer_clockevent); - itimer_clockevent.min_delta_ns = - clockevent_delta2ns(1, &itimer_clockevent); - err = clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC); + err = clocksource_register_hz(&timer_clocksource, NSEC_PER_SEC/TIMER_MULTIPLIER); if (err) { printk(KERN_ERR "clocksource_register_hz returned %d\n", err); return; } - clockevents_register_device(&itimer_clockevent); + clockevents_register_device(&timer_clockevent); } void read_persistent_clock(struct timespec *ts) { - long long nsecs = os_nsecs(); + long long nsecs = os_persistent_clock_emulation(); set_normalized_timespec(ts, nsecs / NSEC_PER_SEC, nsecs % NSEC_PER_SEC); @@ -110,6 +121,6 @@ void read_persistent_clock(struct timespec *ts) void __init time_init(void) { - timer_init(); - late_time_init = setup_itimer; + timer_set_signal_handler(); + late_time_init = timer_setup; } diff --git a/arch/um/os-Linux/internal.h b/arch/um/os-Linux/internal.h deleted file mode 100644 index 0dc2c9f..0000000 --- a/arch/um/os-Linux/internal.h +++ /dev/null @@ -1 +0,0 @@ -void alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc); diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c index df9191a..6e36f0f 100644 --- a/arch/um/os-Linux/main.c +++ b/arch/um/os-Linux/main.c @@ -163,13 +163,13 @@ int __init main(int argc, char **argv, char **envp) /* * This signal stuff used to be in the reboot case. However, - * sometimes a SIGVTALRM can come in when we're halting (reproducably + * sometimes a timer signal can come in when we're halting (reproducably * when writing out gcov information, presumably because that takes * some time) and cause a segfault. */ - /* stop timers and set SIGVTALRM to be ignored */ - disable_timer(); + /* stop timers and set timer signal to be ignored */ + os_timer_disable(); /* disable SIGIO for the fds and set SIGIO to be ignored */ err = deactivate_all_fds(); diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c index 7b605e4..4a9be55 100644 --- a/arch/um/os-Linux/signal.c +++ b/arch/um/os-Linux/signal.c @@ -13,7 +13,6 @@ #include <kern_util.h> #include <os.h> #include <sysdep/mcontext.h> -#include "internal.h" void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = { [SIGTRAP] = relay_signal, @@ -23,7 +22,8 @@ void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = { [SIGBUS] = bus_handler, [SIGSEGV] = segv_handler, [SIGIO] = sigio_handler, - [SIGVTALRM] = timer_handler }; + [SIGALRM] = timer_handler +}; static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) { @@ -38,7 +38,7 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) } /* enable signals if sig isn't IRQ signal */ - if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGVTALRM)) + if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGALRM)) unblock_signals(); (*sig_info[sig])(sig, si, &r); @@ -55,8 +55,8 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) #define SIGIO_BIT 0 #define SIGIO_MASK (1 << SIGIO_BIT) -#define SIGVTALRM_BIT 1 -#define SIGVTALRM_MASK (1 << SIGVTALRM_BIT) +#define SIGALRM_BIT 1 +#define SIGALRM_MASK (1 << SIGALRM_BIT) static int signals_enabled; static unsigned int signals_pending; @@ -78,46 +78,47 @@ void sig_handler(int sig, struct siginfo *si, mcontext_t *mc) set_signals(enabled); } -static void real_alarm_handler(mcontext_t *mc) +static void timer_real_alarm_handler(mcontext_t *mc) { struct uml_pt_regs regs; if (mc != NULL) get_regs_from_mc(®s, mc); regs.is_user = 0; - unblock_signals(); - timer_handler(SIGVTALRM, NULL, ®s); + timer_handler(SIGALRM, NULL, ®s); } -void alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc) +void timer_alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc) { int enabled; enabled = signals_enabled; if (!signals_enabled) { - signals_pending |= SIGVTALRM_MASK; + signals_pending |= SIGALRM_MASK; return; } block_signals(); - - real_alarm_handler(mc); + timer_real_alarm_handler(mc); set_signals(enabled); } -void timer_init(void) +void timer_set_signal_handler(void) { - set_handler(SIGVTALRM); + set_handler(SIGALRM); } void set_sigstack(void *sig_stack, int size) { - stack_t stack = ((stack_t) { .ss_flags = 0, - .ss_sp = (__ptr_t) sig_stack, - .ss_size = size - sizeof(void *) }); + stack_t stack = ((stack_t) { + .ss_flags = 0, + .ss_sp = (__ptr_t) sig_stack, + .ss_size = size - sizeof(void *) + }); - if (sigaltstack(&stack, NULL) != 0) + if (sigaltstack(&stack, NULL) != 0) { panic("enabling signal stack failed, errno = %d\n", errno); + } } static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = { @@ -129,10 +130,9 @@ static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = { [SIGIO] = sig_handler, [SIGWINCH] = sig_handler, - [SIGVTALRM] = alarm_handler + [SIGALRM] = timer_alarm_handler }; - static void hard_handler(int sig, siginfo_t *si, void *p) { struct ucontext *uc = p; @@ -186,9 +186,9 @@ void set_handler(int sig) /* block irq ones */ sigemptyset(&action.sa_mask); - sigaddset(&action.sa_mask, SIGVTALRM); sigaddset(&action.sa_mask, SIGIO); sigaddset(&action.sa_mask, SIGWINCH); + sigaddset(&action.sa_mask, SIGALRM); if (sig == SIGSEGV) flags |= SA_NODEFER; @@ -281,8 +281,8 @@ void unblock_signals(void) if (save_pending & SIGIO_MASK) sig_handler_common(SIGIO, NULL, NULL); - if (save_pending & SIGVTALRM_MASK) - real_alarm_handler(NULL); + if (save_pending & SIGALRM_MASK) + timer_real_alarm_handler(NULL); } } diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index 908579f..f669f9d 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -47,7 +47,7 @@ static int ptrace_dump_regs(int pid) * Signals that are OK to receive in the stub - we'll just continue it. * SIGWINCH will happen when UML is inside a detached screen. */ -#define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH)) +#define STUB_SIG_MASK ((1 << SIGALRM) | (1 << SIGWINCH)) /* Signals that the stub will finish with - anything else is an error */ #define STUB_DONE_MASK (1 << SIGTRAP) @@ -199,12 +199,23 @@ static int userspace_tramp(void *stack) { void *addr; int err; + timer_t timer; + + struct stub_data *data = (struct stub_data *) stack; ptrace(PTRACE_TRACEME, 0, 0, 0); signal(SIGTERM, SIG_DFL); signal(SIGWINCH, SIG_IGN); - err = set_interval(); + + err = os_timer_create(&timer); + if (err) { + printk(UM_KERN_ERR "userspace_tramp - creation of timer failed, " + "errno = %d\n", err); + exit(1); + } + + err = os_timer_set_interval(&timer, &data->timer); if (err) { printk(UM_KERN_ERR "userspace_tramp - setting timer failed, " "errno = %d\n", err); @@ -271,8 +282,9 @@ int userspace_pid[NR_CPUS]; int start_userspace(unsigned long stub_stack) { void *stack; - unsigned long sp; + unsigned long sp, remain; int pid, status, n, flags, err; + struct stub_data *data = (struct stub_data *) stub_stack; stack = mmap(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, @@ -292,6 +304,18 @@ int start_userspace(unsigned long stub_stack) else flags |= SIGCHLD; + remain = os_timer_remain(NULL); + if (remain == 0) + remain = UM_NSEC_PER_SEC / UM_HZ; + + *data = ((struct stub_data) { + .timer = ((struct itimerspec) + { .it_value.tv_sec = 0, + .it_value.tv_nsec = remain, + .it_interval.tv_sec = 0, + .it_interval.tv_nsec = UM_NSEC_PER_SEC / UM_HZ }) + }); + pid = clone(userspace_tramp, (void *) sp, flags, (void *) stub_stack); if (pid < 0) { err = -errno; @@ -308,7 +332,7 @@ int start_userspace(unsigned long stub_stack) "errno = %d\n", errno); goto out_kill; } - } while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM)); + } while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGALRM)); if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) { err = -EINVAL; @@ -341,8 +365,6 @@ int start_userspace(unsigned long stub_stack) void userspace(struct uml_pt_regs *regs) { - struct itimerval timer; - unsigned long long nsecs, now; int err, status, op, pid = userspace_pid[0]; /* To prevent races if using_sysemu changes under us.*/ int local_using_sysemu; @@ -351,13 +373,8 @@ void userspace(struct uml_pt_regs *regs) /* Handle any immediate reschedules or signals */ interrupt_end(); - if (getitimer(ITIMER_VIRTUAL, &timer)) - printk(UM_KERN_ERR "Failed to get itimer, errno = %d\n", errno); - nsecs = timer.it_value.tv_sec * UM_NSEC_PER_SEC + - timer.it_value.tv_usec * UM_NSEC_PER_USEC; - nsecs += os_nsecs(); - while (1) { + /* * This can legitimately fail if the process loads a * bogus value into a segment register. It will @@ -428,19 +445,7 @@ void userspace(struct uml_pt_regs *regs) case SIGTRAP: relay_signal(SIGTRAP, (struct siginfo *)&si, regs); break; - case SIGVTALRM: - now = os_nsecs(); - if (now < nsecs) - break; - block_signals(); - (*sig_info[sig])(sig, (struct siginfo *)&si, regs); - unblock_signals(); - nsecs = timer.it_value.tv_sec * - UM_NSEC_PER_SEC + - timer.it_value.tv_usec * - UM_NSEC_PER_USEC; - nsecs += os_nsecs(); - break; + case SIGALRM: case SIGIO: case SIGILL: case SIGBUS: @@ -487,8 +492,8 @@ __initcall(init_thread_regs); int copy_context_skas0(unsigned long new_stack, int pid) { - struct timeval tv = { .tv_sec = 0, .tv_usec = UM_USEC_PER_SEC / UM_HZ }; int err; + unsigned long remain; unsigned long current_stack = current_stub_stack(); struct stub_data *data = (struct stub_data *) current_stack; struct stub_data *child_data = (struct stub_data *) new_stack; @@ -499,11 +504,19 @@ int copy_context_skas0(unsigned long new_stack, int pid) * prepare offset and fd of child's stack as argument for parent's * and child's mmap2 calls */ - *data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset), - .fd = new_fd, - .timer = ((struct itimerval) - { .it_value = tv, - .it_interval = tv }) }); + remain = os_timer_remain(NULL); + if (remain == 0) + remain = UM_NSEC_PER_SEC / UM_HZ; + + *data = ((struct stub_data) { + .offset = MMAP_OFFSET(new_offset), + .fd = new_fd, + .timer = ((struct itimerspec) + { .it_value.tv_sec = 0, + .it_value.tv_nsec = remain, + .it_interval.tv_sec = 0, + .it_interval.tv_nsec = UM_NSEC_PER_SEC / UM_HZ }) + }); err = ptrace_setregs(pid, thread_regs); if (err < 0) { diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c index e9824d5..0e2bb7d 100644 --- a/arch/um/os-Linux/time.c +++ b/arch/um/os-Linux/time.c @@ -1,4 +1,5 @@ /* + * Copyright (C) 2012-2014 Cisco Systems * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com) * Licensed under the GPL */ @@ -10,177 +11,172 @@ #include <sys/time.h> #include <kern_util.h> #include <os.h> -#include "internal.h" +#include <string.h> +#include <timer-internal.h> -int set_interval(void) -{ - int usec = UM_USEC_PER_SEC / UM_HZ; - struct itimerval interval = ((struct itimerval) { { 0, usec }, - { 0, usec } }); - - if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1) - return -errno; +static timer_t event_high_res_timer = 0; - return 0; +static inline long long timeval_to_ns(const struct timeval *tv) +{ + return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) + + tv->tv_usec * UM_NSEC_PER_USEC; } -int timer_one_shot(int ticks) +static inline long long timespec_to_ns(const struct timespec *ts) { - unsigned long usec = ticks * UM_USEC_PER_SEC / UM_HZ; - unsigned long sec = usec / UM_USEC_PER_SEC; - struct itimerval interval; - - usec %= UM_USEC_PER_SEC; - interval = ((struct itimerval) { { 0, 0 }, { sec, usec } }); + return ((long long) ts->tv_sec * UM_NSEC_PER_SEC) + + ts->tv_nsec; +} - if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1) - return -errno; +long long os_persistent_clock_emulation (void) { + struct timespec realtime_tp; - return 0; + clock_gettime(CLOCK_REALTIME, &realtime_tp); + return timespec_to_ns(&realtime_tp); } /** - * timeval_to_ns - Convert timeval to nanoseconds - * @ts: pointer to the timeval variable to be converted - * - * Returns the scalar nanosecond representation of the timeval - * parameter. - * - * Ripped from linux/time.h because it's a kernel header, and thus - * unusable from here. + * os_timer_create() - create an new posix (interval) timer */ -static inline long long timeval_to_ns(const struct timeval *tv) -{ - return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) + - tv->tv_usec * UM_NSEC_PER_USEC; +int os_timer_create(void* timer) { + + timer_t* t = timer; + + if(t == NULL) { + t = &event_high_res_timer; + } + + if (timer_create( + CLOCK_MONOTONIC, + NULL, + t) == -1) { + return -1; + } + return 0; } -long long disable_timer(void) +int os_timer_set_interval(void* timer, void* i) { - struct itimerval time = ((struct itimerval) { { 0, 0 }, { 0, 0 } }); - long long remain, max = UM_NSEC_PER_SEC / UM_HZ; + struct itimerspec its; + unsigned long long nsec; + timer_t* t = timer; + struct itimerspec* its_in = i; - if (setitimer(ITIMER_VIRTUAL, &time, &time) < 0) - printk(UM_KERN_ERR "disable_timer - setitimer failed, " - "errno = %d\n", errno); + if(t == NULL) { + t = &event_high_res_timer; + } - remain = timeval_to_ns(&time.it_value); - if (remain > max) - remain = max; + nsec = UM_NSEC_PER_SEC / UM_HZ; - return remain; -} + if(its_in != NULL) { + its.it_value.tv_sec = its_in->it_value.tv_sec; + its.it_value.tv_nsec = its_in->it_value.tv_nsec; + } else { + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = nsec; + } -long long os_nsecs(void) -{ - struct timeval tv; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = nsec; - gettimeofday(&tv, NULL); - return timeval_to_ns(&tv); -} + if(timer_settime(*t, 0, &its, NULL) == -1) { + return -errno; + } -#ifdef UML_CONFIG_NO_HZ_COMMON -static int after_sleep_interval(struct timespec *ts) -{ return 0; } -static void deliver_alarm(void) +/** + * os_timer_remain() - returns the remaining nano seconds of the given interval + * timer + * Because this is the remaining time of an interval timer, which correspondends + * to HZ, this value can never be bigger than one second. Just + * the nanosecond part of the timer is returned. + * The returned time is relative to the start time of the interval timer. + * Return an negative value in an error case. + */ +long os_timer_remain(void* timer) { - alarm_handler(SIGVTALRM, NULL, NULL); -} + struct itimerspec its; + timer_t* t = timer; -static unsigned long long sleep_time(unsigned long long nsecs) -{ - return nsecs; -} + if(t == NULL) { + t = &event_high_res_timer; + } -#else -unsigned long long last_tick; -unsigned long long skew; + if(timer_gettime(t, &its) == -1) { + return -errno; + } + + return its.it_value.tv_nsec; +} -static void deliver_alarm(void) +int os_timer_one_shot(int ticks) { - unsigned long long this_tick = os_nsecs(); - int one_tick = UM_NSEC_PER_SEC / UM_HZ; + struct itimerspec its; + unsigned long long nsec; + unsigned long sec; - /* Protection against the host's time going backwards */ - if ((last_tick != 0) && (this_tick < last_tick)) - this_tick = last_tick; + nsec = (ticks + 1); + sec = nsec / UM_NSEC_PER_SEC; + nsec = nsec % UM_NSEC_PER_SEC; - if (last_tick == 0) - last_tick = this_tick - one_tick; + its.it_value.tv_sec = nsec / UM_NSEC_PER_SEC; + its.it_value.tv_nsec = nsec; - skew += this_tick - last_tick; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = 0; // we cheat here - while (skew >= one_tick) { - alarm_handler(SIGVTALRM, NULL, NULL); - skew -= one_tick; - } - - last_tick = this_tick; + timer_settime(event_high_res_timer, 0, &its, NULL); + return 0; } -static unsigned long long sleep_time(unsigned long long nsecs) +/** + * os_timer_disable() - disable the posix (interval) timer + * Returns the remaining interval timer time in nanoseconds + */ +long long os_timer_disable(void) { - return nsecs > skew ? nsecs - skew : 0; + struct itimerspec its; + + memset(&its, 0, sizeof(struct itimerspec)); + timer_settime(event_high_res_timer, 0, &its, &its); + + return its.it_value.tv_sec * UM_NSEC_PER_SEC + its.it_value.tv_nsec; } -static inline long long timespec_to_us(const struct timespec *ts) +long long os_vnsecs(void) { - return ((long long) ts->tv_sec * UM_USEC_PER_SEC) + - ts->tv_nsec / UM_NSEC_PER_USEC; + struct timespec ts; + + clock_gettime(CLOCK_PROCESS_CPUTIME_ID,&ts); + return timespec_to_ns(&ts); } -static int after_sleep_interval(struct timespec *ts) +long long os_nsecs(void) { - int usec = UM_USEC_PER_SEC / UM_HZ; - long long start_usecs = timespec_to_us(ts); - struct timeval tv; - struct itimerval interval; - - /* - * It seems that rounding can increase the value returned from - * setitimer to larger than the one passed in. Over time, - * this will cause the remaining time to be greater than the - * tick interval. If this happens, then just reduce the first - * tick to the interval value. - */ - if (start_usecs > usec) - start_usecs = usec; - - start_usecs -= skew / UM_NSEC_PER_USEC; - if (start_usecs < 0) - start_usecs = 0; - - tv = ((struct timeval) { .tv_sec = start_usecs / UM_USEC_PER_SEC, - .tv_usec = start_usecs % UM_USEC_PER_SEC }); - interval = ((struct itimerval) { { 0, usec }, tv }); - - if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1) - return -errno; + struct timespec ts; - return 0; + clock_gettime(CLOCK_MONOTONIC,&ts); + return timespec_to_ns(&ts); } -#endif -void idle_sleep(unsigned long long nsecs) +/** + * os_idle_sleep() - sleep for a given time of nsecs + * @nsecs: nanoseconds to sleep + */ +void os_idle_sleep(unsigned long long nsecs) { struct timespec ts; - /* - * nsecs can come in as zero, in which case, this starts a - * busy loop. To prevent this, reset nsecs to the tick - * interval if it is zero. - */ - if (nsecs == 0) - nsecs = UM_NSEC_PER_SEC / UM_HZ; - - nsecs = sleep_time(nsecs); - ts = ((struct timespec) { .tv_sec = nsecs / UM_NSEC_PER_SEC, - .tv_nsec = nsecs % UM_NSEC_PER_SEC }); - - if (nanosleep(&ts, &ts) == 0) - deliver_alarm(); - after_sleep_interval(&ts); + if (nsecs <= 0) { + return; + } + + ts = ((struct timespec) { + .tv_sec = nsecs / UM_NSEC_PER_SEC, + .tv_nsec = nsecs % UM_NSEC_PER_SEC + }); + + clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL); } ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel