| Message ID | 20170113131731.1246-11-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Fri, 01/13 14:17, Paolo Bonzini wrote: > diff --git a/block/qed.c b/block/qed.c > index 7f1c508..a21d025 100644 > --- a/block/qed.c > +++ b/block/qed.c > @@ -345,10 +345,22 @@ static void qed_need_check_timer_cb(void *opaque) > > trace_qed_need_check_timer_cb(s); > > + qed_acquire(s); > qed_plug_allocating_write_reqs(s); > > /* Ensure writes are on disk before clearing flag */ > bdrv_aio_flush(s->bs->file->bs, qed_clear_need_check, s); > + qed_release(s); > +} > + > +void qed_acquire(BDRVQEDState *s) > +{ > + aio_context_acquire(bdrv_get_aio_context(s->bs)); > +} > + > +void qed_release(BDRVQEDState *s) > +{ > + aio_context_release(bdrv_get_aio_context(s->bs)); > } > > static void qed_start_need_check_timer(BDRVQEDState *s) > diff --git a/block/qed.h b/block/qed.h > index 9676ab9..ce8c314 100644 > --- a/block/qed.h > +++ b/block/qed.h > @@ -198,6 +198,9 @@ enum { > */ > typedef void QEDFindClusterFunc(void *opaque, int ret, uint64_t offset, size_t len); > > +void qed_acquire(BDRVQEDState *s); > +void qed_release(BDRVQEDState *s); > + Why cannot these be local (static) functions, in block/qed.c? > /** > * Generic callback for chaining async callbacks > */ Fam
On 16/01/2017 14:07, Fam Zheng wrote: > On Fri, 01/13 14:17, Paolo Bonzini wrote: >> diff --git a/block/qed.c b/block/qed.c >> index 7f1c508..a21d025 100644 >> --- a/block/qed.c >> +++ b/block/qed.c >> @@ -345,10 +345,22 @@ static void qed_need_check_timer_cb(void *opaque) >> >> trace_qed_need_check_timer_cb(s); >> >> + qed_acquire(s); >> qed_plug_allocating_write_reqs(s); >> >> /* Ensure writes are on disk before clearing flag */ >> bdrv_aio_flush(s->bs->file->bs, qed_clear_need_check, s); >> + qed_release(s); >> +} >> + >> +void qed_acquire(BDRVQEDState *s) >> +{ >> + aio_context_acquire(bdrv_get_aio_context(s->bs)); >> +} >> + >> +void qed_release(BDRVQEDState *s) >> +{ >> + aio_context_release(bdrv_get_aio_context(s->bs)); >> } >> >> static void qed_start_need_check_timer(BDRVQEDState *s) >> diff --git a/block/qed.h b/block/qed.h >> index 9676ab9..ce8c314 100644 >> --- a/block/qed.h >> +++ b/block/qed.h >> @@ -198,6 +198,9 @@ enum { >> */ >> typedef void QEDFindClusterFunc(void *opaque, int ret, uint64_t offset, size_t len); >> >> +void qed_acquire(BDRVQEDState *s); >> +void qed_release(BDRVQEDState *s); >> + > > Why cannot these be local (static) functions, in block/qed.c? Patch 13 uses them elsewhere. Should I put them in a separate patch? Paolo >> /** >> * Generic callback for chaining async callbacks >> */ > > Fam > >
On Mon, 01/16 14:32, Paolo Bonzini wrote: > > Why cannot these be local (static) functions, in block/qed.c? > > Patch 13 uses them elsewhere. Should I put them in a separate patch? Thanks, this is fine! Fam
On Fri, Jan 13, 2017 at 02:17:25PM +0100, Paolo Bonzini wrote: > diff --git a/block/null.c b/block/null.c > index b300390..356209a 100644 > --- a/block/null.c > +++ b/block/null.c > @@ -141,7 +141,11 @@ static void null_bh_cb(void *opaque) > static void null_timer_cb(void *opaque) > { > NullAIOCB *acb = opaque; > + AioContext *ctx = bdrv_get_aio_context(acb->common.bs); > + > + aio_context_acquire(ctx); > acb->common.cb(acb->common.opaque, 0); > + aio_context_release(ctx); > timer_deinit(&acb->timer); > qemu_aio_unref(acb); Is qemu_aio_unref() thread-safe?
On 18/01/2017 16:43, Stefan Hajnoczi wrote: > On Fri, Jan 13, 2017 at 02:17:25PM +0100, Paolo Bonzini wrote: >> diff --git a/block/null.c b/block/null.c >> index b300390..356209a 100644 >> --- a/block/null.c >> +++ b/block/null.c >> @@ -141,7 +141,11 @@ static void null_bh_cb(void *opaque) >> static void null_timer_cb(void *opaque) >> { >> NullAIOCB *acb = opaque; >> + AioContext *ctx = bdrv_get_aio_context(acb->common.bs); >> + >> + aio_context_acquire(ctx); >> acb->common.cb(acb->common.opaque, 0); >> + aio_context_release(ctx); >> timer_deinit(&acb->timer); >> qemu_aio_unref(acb); > > Is qemu_aio_unref() thread-safe? qemu_aio_ref()/qemu_aio_unref() is only used by bdrv_aio_cancel, which in turn is not used by dataplane. So in the multithreaded case qemu_aio_unref() is effectively qemu_aio_free(). Probably needs more documentation, or a different implementation of bdrv_aio_cancel (e.g. replacing the reference counting with a NotifierList of some kind). Let me know what you prefer for v2. Paolo
On Wed, Jan 18, 2017 at 05:44:24PM +0100, Paolo Bonzini wrote: > On 18/01/2017 16:43, Stefan Hajnoczi wrote: > > On Fri, Jan 13, 2017 at 02:17:25PM +0100, Paolo Bonzini wrote: > >> diff --git a/block/null.c b/block/null.c > >> index b300390..356209a 100644 > >> --- a/block/null.c > >> +++ b/block/null.c > >> @@ -141,7 +141,11 @@ static void null_bh_cb(void *opaque) > >> static void null_timer_cb(void *opaque) > >> { > >> NullAIOCB *acb = opaque; > >> + AioContext *ctx = bdrv_get_aio_context(acb->common.bs); > >> + > >> + aio_context_acquire(ctx); > >> acb->common.cb(acb->common.opaque, 0); > >> + aio_context_release(ctx); > >> timer_deinit(&acb->timer); > >> qemu_aio_unref(acb); > > > > Is qemu_aio_unref() thread-safe? > > qemu_aio_ref()/qemu_aio_unref() is only used by bdrv_aio_cancel, which > in turn is not used by dataplane. So in the multithreaded case > qemu_aio_unref() is effectively qemu_aio_free(). > > Probably needs more documentation, or a different implementation of > bdrv_aio_cancel (e.g. replacing the reference counting with a > NotifierList of some kind). Let me know what you prefer for v2. Documentation is fine. I just checked and see that virtio-scsi dataplane uses blk_aio_cancel_async() so the aio refcount is never touched - no race. Stefan
diff --git a/aio-posix.c b/aio-posix.c index 3fd64fb..8d79cf3 100644 --- a/aio-posix.c +++ b/aio-posix.c @@ -454,9 +454,7 @@ bool aio_dispatch(AioContext *ctx, bool dispatch_fds) } /* Run our timers */ - aio_context_acquire(ctx); progress |= timerlistgroup_run_timers(&ctx->tlg); - aio_context_release(ctx); return progress; } diff --git a/aio-win32.c b/aio-win32.c index ab6d0e5..810e1c6 100644 --- a/aio-win32.c +++ b/aio-win32.c @@ -403,9 +403,7 @@ bool aio_poll(AioContext *ctx, bool blocking) progress |= aio_dispatch_handlers(ctx, event); } while (count > 0); - aio_context_acquire(ctx); progress |= timerlistgroup_run_timers(&ctx->tlg); - aio_context_release(ctx); return progress; } diff --git a/block/curl.c b/block/curl.c index 792fef8..65e6da1 100644 --- a/block/curl.c +++ b/block/curl.c @@ -424,9 +424,11 @@ static void curl_multi_timeout_do(void *arg) return; } + aio_context_acquire(s->aio_context); curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running); curl_multi_check_completion(s); + aio_context_release(s->aio_context); #else abort(); #endif diff --git a/block/iscsi.c b/block/iscsi.c index 6aeeb9e..e1f10d6 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -174,7 +174,7 @@ static void iscsi_retry_timer_expired(void *opaque) struct IscsiTask *iTask = opaque; iTask->complete = 1; if (iTask->co) { - qemu_coroutine_enter(iTask->co); + aio_co_wake(iTask->co); } } @@ -1388,16 +1388,20 @@ static void iscsi_nop_timed_event(void *opaque) { IscsiLun *iscsilun = opaque; + aio_context_acquire(iscsilun->aio_context); if (iscsi_get_nops_in_flight(iscsilun->iscsi) >= MAX_NOP_FAILURES) { error_report("iSCSI: NOP timeout. Reconnecting..."); iscsilun->request_timed_out = true; } else if (iscsi_nop_out_async(iscsilun->iscsi, NULL, NULL, 0, NULL) != 0) { error_report("iSCSI: failed to sent NOP-Out. Disabling NOP messages."); - return; + goto out; } timer_mod(iscsilun->nop_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL); iscsi_set_events(iscsilun); + +out: + aio_context_release(iscsilun->aio_context); } static void iscsi_readcapacity_sync(IscsiLun *iscsilun, Error **errp) diff --git a/block/null.c b/block/null.c index b300390..356209a 100644 --- a/block/null.c +++ b/block/null.c @@ -141,7 +141,11 @@ static void null_bh_cb(void *opaque) static void null_timer_cb(void *opaque) { NullAIOCB *acb = opaque; + AioContext *ctx = bdrv_get_aio_context(acb->common.bs); + + aio_context_acquire(ctx); acb->common.cb(acb->common.opaque, 0); + aio_context_release(ctx); timer_deinit(&acb->timer); qemu_aio_unref(acb); } diff --git a/block/qed.c b/block/qed.c index 7f1c508..a21d025 100644 --- a/block/qed.c +++ b/block/qed.c @@ -345,10 +345,22 @@ static void qed_need_check_timer_cb(void *opaque) trace_qed_need_check_timer_cb(s); + qed_acquire(s); qed_plug_allocating_write_reqs(s); /* Ensure writes are on disk before clearing flag */ bdrv_aio_flush(s->bs->file->bs, qed_clear_need_check, s); + qed_release(s); +} + +void qed_acquire(BDRVQEDState *s) +{ + aio_context_acquire(bdrv_get_aio_context(s->bs)); +} + +void qed_release(BDRVQEDState *s) +{ + aio_context_release(bdrv_get_aio_context(s->bs)); } static void qed_start_need_check_timer(BDRVQEDState *s) diff --git a/block/qed.h b/block/qed.h index 9676ab9..ce8c314 100644 --- a/block/qed.h +++ b/block/qed.h @@ -198,6 +198,9 @@ enum { */ typedef void QEDFindClusterFunc(void *opaque, int ret, uint64_t offset, size_t len); +void qed_acquire(BDRVQEDState *s); +void qed_release(BDRVQEDState *s); + /** * Generic callback for chaining async callbacks */ diff --git a/block/throttle-groups.c b/block/throttle-groups.c index 17b2efb..aade5de 100644 --- a/block/throttle-groups.c +++ b/block/throttle-groups.c @@ -416,7 +416,9 @@ static void timer_cb(BlockBackend *blk, bool is_write) qemu_mutex_unlock(&tg->lock); /* Run the request that was waiting for this timer */ + aio_context_acquire(blk_get_aio_context(blk)); empty_queue = !qemu_co_enter_next(&blkp->throttled_reqs[is_write]); + aio_context_release(blk_get_aio_context(blk)); /* If the request queue was empty then we have to take care of * scheduling the next one */ diff --git a/util/qemu-coroutine-sleep.c b/util/qemu-coroutine-sleep.c index 25de3ed..9c56550 100644 --- a/util/qemu-coroutine-sleep.c +++ b/util/qemu-coroutine-sleep.c @@ -25,7 +25,7 @@ static void co_sleep_cb(void *opaque) { CoSleepCB *sleep_cb = opaque; - qemu_coroutine_enter(sleep_cb->co); + aio_co_wake(sleep_cb->co); } void coroutine_fn co_aio_sleep_ns(AioContext *ctx, QEMUClockType type,
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- aio-posix.c | 2 -- aio-win32.c | 2 -- block/curl.c | 2 ++ block/iscsi.c | 8 ++++++-- block/null.c | 4 ++++ block/qed.c | 12 ++++++++++++ block/qed.h | 3 +++ block/throttle-groups.c | 2 ++ util/qemu-coroutine-sleep.c | 2 +- 9 files changed, 30 insertions(+), 7 deletions(-)