| Message ID | 20180119205847.7141-5-jsnow@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | blockjob: refactor mirror_throttle | expand |
On 2018-01-19 21:58, John Snow wrote: > Instead of only sleeping for 0ms when we've hit a timeout, optionally > take a longer more explicit delay_ns that always forces the sleep. > > Signed-off-by: John Snow <jsnow@redhat.com> > --- > block/mirror.c | 4 ++-- > blockjob.c | 9 ++++----- > include/block/blockjob_int.h | 10 +++++++--- > 3 files changed, 13 insertions(+), 10 deletions(-) [...] > diff --git a/blockjob.c b/blockjob.c > index 6f2e709b51..51c0eb5d9e 100644 > --- a/blockjob.c > +++ b/blockjob.c > @@ -906,12 +906,11 @@ void block_job_yield(BlockJob *job) > block_job_pause_point(job); > } > > -void block_job_relax(BlockJob *job) > +void block_job_relax(BlockJob *job, int64_t delay_ns) > { > - int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); > - > - if (now - job->last_enter_ns > SLICE_TIME) { > - block_job_sleep_ns(job, 0); > + if (delay_ns || (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - \ > + job->last_enter_ns > SLICE_TIME)) { > + block_job_sleep_ns(job, delay_ns); I can't say I like the readability of that any better... (And I'd argue that if delay_ns > 0, the one superfluous call to qemu_clock_get_ns() isn't going to harm performance.) > } else { > block_job_pause_point(job); > } > diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h > index 553784d86f..5f1520fab7 100644 > --- a/include/block/blockjob_int.h > +++ b/include/block/blockjob_int.h > @@ -160,11 +160,15 @@ void block_job_yield(BlockJob *job); > /** > * block_job_relax: > * @job: The job that calls the function. > + * @delay_ns: The amount of time to sleep for > * > - * Yield if it has been SLICE_TIME nanoseconds since the last yield. > - * Otherwise, check if we need to pause, and yield if so. > + * Sleep for delay_ns nanoseconds. > + * > + * If delay_ns is 0, yield if it has been SLICE_TIME > + * nanoseconds since the last yield. Otherwise, check > + * if we need to yield for a pause event. That "Otherwise" now sounds as if it refers to the "If delay_ns is 0". Code change is OK, but this comment needs some fixing. Max > */ > -void block_job_relax(BlockJob *job); > +void block_job_relax(BlockJob *job, int64_t delay_ns); > > /** > * block_job_pause_all: >
diff --git a/block/mirror.c b/block/mirror.c index 36c681c7a1..3c73caed5e 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -610,7 +610,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) int bytes = MIN(s->bdev_length - offset, QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); - block_job_relax(&s->common); + block_job_relax(&s->common, 0); if (block_job_is_cancelled(&s->common)) { s->initial_zeroing_ongoing = false; @@ -638,7 +638,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) int bytes = MIN(s->bdev_length - offset, QEMU_ALIGN_DOWN(INT_MAX, s->granularity)); - block_job_relax(&s->common); + block_job_relax(&s->common, 0); if (block_job_is_cancelled(&s->common)) { return 0; diff --git a/blockjob.c b/blockjob.c index 6f2e709b51..51c0eb5d9e 100644 --- a/blockjob.c +++ b/blockjob.c @@ -906,12 +906,11 @@ void block_job_yield(BlockJob *job) block_job_pause_point(job); } -void block_job_relax(BlockJob *job) +void block_job_relax(BlockJob *job, int64_t delay_ns) { - int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); - - if (now - job->last_enter_ns > SLICE_TIME) { - block_job_sleep_ns(job, 0); + if (delay_ns || (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - \ + job->last_enter_ns > SLICE_TIME)) { + block_job_sleep_ns(job, delay_ns); } else { block_job_pause_point(job); } diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h index 553784d86f..5f1520fab7 100644 --- a/include/block/blockjob_int.h +++ b/include/block/blockjob_int.h @@ -160,11 +160,15 @@ void block_job_yield(BlockJob *job); /** * block_job_relax: * @job: The job that calls the function. + * @delay_ns: The amount of time to sleep for * - * Yield if it has been SLICE_TIME nanoseconds since the last yield. - * Otherwise, check if we need to pause, and yield if so. + * Sleep for delay_ns nanoseconds. + * + * If delay_ns is 0, yield if it has been SLICE_TIME + * nanoseconds since the last yield. Otherwise, check + * if we need to yield for a pause event. */ -void block_job_relax(BlockJob *job); +void block_job_relax(BlockJob *job, int64_t delay_ns); /** * block_job_pause_all:
Instead of only sleeping for 0ms when we've hit a timeout, optionally take a longer more explicit delay_ns that always forces the sleep. Signed-off-by: John Snow <jsnow@redhat.com> --- block/mirror.c | 4 ++-- blockjob.c | 9 ++++----- include/block/blockjob_int.h | 10 +++++++--- 3 files changed, 13 insertions(+), 10 deletions(-)