Message ID | 1325858501-25741-2-git-send-email-stefanha@linux.vnet.ibm.com |
---|---|
State | New |
Headers | show |
Am 06.01.2012 15:01, schrieb Stefan Hajnoczi: > Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> > --- > Makefile.objs | 1 + > qemu-coroutine-sleep.c | 38 ++++++++++++++++++++++++++++++++++++++ > qemu-coroutine.h | 6 ++++++ > 3 files changed, 45 insertions(+), 0 deletions(-) > create mode 100644 qemu-coroutine-sleep.c > diff --git a/qemu-coroutine.h b/qemu-coroutine.h > index 8a55fe1..bae1ffe 100644 > --- a/qemu-coroutine.h > +++ b/qemu-coroutine.h > @@ -17,6 +17,7 @@ > > #include <stdbool.h> > #include "qemu-queue.h" > +#include "qemu-timer.h" > > /** > * Coroutines are a mechanism for stack switching and can be used for > @@ -199,4 +200,9 @@ void qemu_co_rwlock_wrlock(CoRwlock *lock); > */ > void qemu_co_rwlock_unlock(CoRwlock *lock); > > +/** > + * Yield the coroutine for a given duration > + */ > +void coroutine_fn co_sleep_ns(QEMUClock *clock, int64_t ns); > + > #endif /* QEMU_COROUTINE_H */ As you mentioned on IRC yesterday, timers don't work in the tools. There should probably be a warning in the comment (or a fix before this is merged) Kevin
On Thu, Jan 12, 2012 at 10:13 AM, Kevin Wolf <kwolf@redhat.com> wrote: > Am 06.01.2012 15:01, schrieb Stefan Hajnoczi: >> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> >> --- >> Makefile.objs | 1 + >> qemu-coroutine-sleep.c | 38 ++++++++++++++++++++++++++++++++++++++ >> qemu-coroutine.h | 6 ++++++ >> 3 files changed, 45 insertions(+), 0 deletions(-) >> create mode 100644 qemu-coroutine-sleep.c > >> diff --git a/qemu-coroutine.h b/qemu-coroutine.h >> index 8a55fe1..bae1ffe 100644 >> --- a/qemu-coroutine.h >> +++ b/qemu-coroutine.h >> @@ -17,6 +17,7 @@ >> >> #include <stdbool.h> >> #include "qemu-queue.h" >> +#include "qemu-timer.h" >> >> /** >> * Coroutines are a mechanism for stack switching and can be used for >> @@ -199,4 +200,9 @@ void qemu_co_rwlock_wrlock(CoRwlock *lock); >> */ >> void qemu_co_rwlock_unlock(CoRwlock *lock); >> >> +/** >> + * Yield the coroutine for a given duration >> + */ >> +void coroutine_fn co_sleep_ns(QEMUClock *clock, int64_t ns); >> + >> #endif /* QEMU_COROUTINE_H */ > > As you mentioned on IRC yesterday, timers don't work in the tools. There > should probably be a warning in the comment (or a fix before this is merged) This is something I'm looking at right now and will probably want to discuss with Paolo. In a coroutine we're probably using a main loop and timers should be available there. In general, the problem we're starting to see is that some block layer features are using timers (I/O throttling, QED deferred dirty bit clearing, image streaming). The question is do we isolate this functionality so it is unavailable from a qemu-tool world when there's no main loop, or do we move everything into a main loop? Stefan
On Thu, Jan 12, 2012 at 10:13 AM, Kevin Wolf <kwolf@redhat.com> wrote: > Am 06.01.2012 15:01, schrieb Stefan Hajnoczi: >> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> >> --- >> Makefile.objs | 1 + >> qemu-coroutine-sleep.c | 38 ++++++++++++++++++++++++++++++++++++++ >> qemu-coroutine.h | 6 ++++++ >> 3 files changed, 45 insertions(+), 0 deletions(-) >> create mode 100644 qemu-coroutine-sleep.c > >> diff --git a/qemu-coroutine.h b/qemu-coroutine.h >> index 8a55fe1..bae1ffe 100644 >> --- a/qemu-coroutine.h >> +++ b/qemu-coroutine.h >> @@ -17,6 +17,7 @@ >> >> #include <stdbool.h> >> #include "qemu-queue.h" >> +#include "qemu-timer.h" >> >> /** >> * Coroutines are a mechanism for stack switching and can be used for >> @@ -199,4 +200,9 @@ void qemu_co_rwlock_wrlock(CoRwlock *lock); >> */ >> void qemu_co_rwlock_unlock(CoRwlock *lock); >> >> +/** >> + * Yield the coroutine for a given duration >> + */ >> +void coroutine_fn co_sleep_ns(QEMUClock *clock, int64_t ns); >> + >> #endif /* QEMU_COROUTINE_H */ > > As you mentioned on IRC yesterday, timers don't work in the tools. There > should probably be a warning in the comment (or a fix before this is merged) I will add a comment to prevent new callers using this inappropriately. qemu-img/qemu-io do not use image streaming so we never hit an abort(3). But I still have an interest in solving the larger problem because QED broken in qemu-tools! So I'll look into using the main loop in qemu-io/qemu-img based on Paolo's patches independently of this image streaming series. Stefan
diff --git a/Makefile.objs b/Makefile.objs index 47fdc82..64d84de 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -13,6 +13,7 @@ oslib-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-thread-posix.o ####################################################################### # coroutines coroutine-obj-y = qemu-coroutine.o qemu-coroutine-lock.o qemu-coroutine-io.o +coroutine-obj-y += qemu-coroutine-sleep.o ifeq ($(CONFIG_UCONTEXT_COROUTINE),y) coroutine-obj-$(CONFIG_POSIX) += coroutine-ucontext.o else diff --git a/qemu-coroutine-sleep.c b/qemu-coroutine-sleep.c new file mode 100644 index 0000000..fd65274 --- /dev/null +++ b/qemu-coroutine-sleep.c @@ -0,0 +1,38 @@ +/* + * QEMU coroutine sleep + * + * Copyright IBM, Corp. 2011 + * + * Authors: + * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> + * + * This work is licensed under the terms of the GNU LGPL, version 2 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#include "qemu-coroutine.h" +#include "qemu-timer.h" + +typedef struct CoSleepCB { + QEMUTimer *ts; + Coroutine *co; +} CoSleepCB; + +static void co_sleep_cb(void *opaque) +{ + CoSleepCB *sleep_cb = opaque; + + qemu_free_timer(sleep_cb->ts); + qemu_coroutine_enter(sleep_cb->co, NULL); +} + +void coroutine_fn co_sleep_ns(QEMUClock *clock, int64_t ns) +{ + CoSleepCB sleep_cb = { + .co = qemu_coroutine_self(), + }; + sleep_cb.ts = qemu_new_timer(clock, SCALE_NS, co_sleep_cb, &sleep_cb); + qemu_mod_timer(sleep_cb.ts, qemu_get_clock_ns(clock) + ns); + qemu_coroutine_yield(); +} diff --git a/qemu-coroutine.h b/qemu-coroutine.h index 8a55fe1..bae1ffe 100644 --- a/qemu-coroutine.h +++ b/qemu-coroutine.h @@ -17,6 +17,7 @@ #include <stdbool.h> #include "qemu-queue.h" +#include "qemu-timer.h" /** * Coroutines are a mechanism for stack switching and can be used for @@ -199,4 +200,9 @@ void qemu_co_rwlock_wrlock(CoRwlock *lock); */ void qemu_co_rwlock_unlock(CoRwlock *lock); +/** + * Yield the coroutine for a given duration + */ +void coroutine_fn co_sleep_ns(QEMUClock *clock, int64_t ns); + #endif /* QEMU_COROUTINE_H */
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> --- Makefile.objs | 1 + qemu-coroutine-sleep.c | 38 ++++++++++++++++++++++++++++++++++++++ qemu-coroutine.h | 6 ++++++ 3 files changed, 45 insertions(+), 0 deletions(-) create mode 100644 qemu-coroutine-sleep.c