Am Sonntag, den 31.05.2015, 23:49 +0200 schrieb Richard Weinberger:
> Am 31.05.2015 um 21:00 schrieb Thomas Meyer:
> > > Ping.
> > > Would be nice to have this patch for the 4.2 merge window.
> >
> > I can provide you the current version of the patch, but I'm not
> > sure if
> > it's ready for inclusion yet.
>
> That's fine. I'll look at it.
> Just rebase it against Linus' tree or uml-next.
> https://git.kernel.org/cgit/linux/kernel/git/rw/uml.git/log/?h=linux
> -next
> > For example:
> > - With this patch I see new zombie processes of UML userspace
> > processes. I'm not sure what's going on here.
> > - Anton reported some hang he sees with this patch
> > - A person from cicso is worried about the potential idle CPU usage
> > after the patch, because of the many timers started, i.e. a host
> > with
> > hundreds of UMLs.
> >
> > Also meanwhile I think is not the correct thing to start a new
> > timer
> > for each UML userspace process, because the timer will also trigger
> > the
> > userspace process, even the corresponding process isn't scheduled
> > by
> > the kernel currently. I think the previous behaviour with the
> > itimer
> > was okay, because the virtual timer only did execute when the
> > process
> > was executing which is the correct thing to do for the currently
> > active
> > task in the UML kernel.
> > I see two solutions for above problem: cascade the kernel timer
> > into
> > the current active task; there is actually no need to start a timer
> > in
> > each userspace process.
> > Start/stop each timer when a userspace process becomes active resp.
> > becomes inactive again.
> > I hope above logic makes some sense at all! What do you think about
> > this?
>
> Hm, we definitely don't want a new timer for each userspace proc. The
> timer
> has to work as a regular clock source.
> But I'll have to read your/Anton's code in detail first.
Hi,
rebased against current Linus' tree:
- Currently I'm not sure at all why the individual itimers are created
for each usespace process and if we need to copy these mechanism for
posix interval timers.
Please have a look at the patch, this should apply cleanly against
linus tree:
commit c091d1f11649d39dbdd1653139954bf1feff0c80
Author: Thomas Meyer <tho...@m3y3r.de>
Date: Sun May 31 19:40:22 2015 +0200
um: Switch clocksource to hrtimers
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 17d4460..a4a434f 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 d824528..2e738b0 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -217,7 +217,7 @@ 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);
@@ -238,12 +238,16 @@ 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 68b9119..3b936f8 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 7a97775..4761f8b 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -45,7 +45,7 @@ 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)
@@ -181,12 +181,23 @@ static int userspace_tramp(void *stack)
void *addr;
int err, fd;
unsigned long long offset;
+ 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);
@@ -249,8 +260,9 @@ 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,
@@ -266,6 +278,18 @@ int start_userspace(unsigned long stub_stack)
flags = CLONE_FILES | 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;
@@ -282,7 +306,7 @@ 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;
@@ -315,8 +339,6 @@ 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;
@@ -325,13 +347,8 @@ 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
@@ -401,19 +418,7 @@ 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:
@@ -460,8 +465,8 @@ __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;
@@ -472,11 +477,19 @@ 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);
}
------------------------------------------------------------------------------
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