Re: [Qemu-devel] [PATCH 1/1] linux-aio: prevent submitting more than MAX_EVENTS

2016-07-13 Thread Roman Penyaev
On Wed, Jul 13, 2016 at 9:43 AM, Paolo Bonzini wrote: > > > On 12/07/2016 19:51, Roman Pen wrote: >> +if (s->io_q.in_flight >= MAX_EVENTS) >> +break; >> QSIMPLEQ_FOREACH(aiocb, &s->io_q.pending, next) { >> iocbs[len++] = &aiocb->iocb; >> -if (l

Re: [Qemu-devel] [PATCH 1/1] linux-aio: prevent submitting more than MAX_EVENTS

2016-07-13 Thread Paolo Bonzini
On 12/07/2016 19:51, Roman Pen wrote: > +if (s->io_q.in_flight >= MAX_EVENTS) > +break; > QSIMPLEQ_FOREACH(aiocb, &s->io_q.pending, next) { > iocbs[len++] = &aiocb->iocb; > -if (len == MAX_QUEUED_IO) { > +if (s->io_q.in_flight + le

Re: [Qemu-devel] [PATCH 1/1] linux-aio: prevent submitting more than MAX_EVENTS

2016-07-12 Thread Fam Zheng
On Tue, 07/12 19:51, Roman Pen wrote: > Invoking io_setup(MAX_EVENTS) we ask kernel to create ring buffer for us > with specified number of events. But kernel ring buffer allocation logic > is a bit tricky (ring buffer is page size aligned + some percpu allocation > are required) so eventually mor

[Qemu-devel] [PATCH 1/1] linux-aio: prevent submitting more than MAX_EVENTS

2016-07-12 Thread Roman Pen
Invoking io_setup(MAX_EVENTS) we ask kernel to create ring buffer for us with specified number of events. But kernel ring buffer allocation logic is a bit tricky (ring buffer is page size aligned + some percpu allocation are required) so eventually more than requested events number is allocated.