Re: [Qemu-devel] [PATCH v3 1/1] linux-aio: prevent submitting more than MAX_EVENTS

2016-07-15 Thread Stefan Hajnoczi
On Wed, Jul 13, 2016 at 03:03:24PM +0200, 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 requir

Re: [Qemu-devel] [PATCH v3 1/1] linux-aio: prevent submitting more than MAX_EVENTS

2016-07-14 Thread Stefan Hajnoczi
On Wed, Jul 13, 2016 at 03:03:24PM +0200, 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 requir

[Qemu-devel] [PATCH v3 1/1] linux-aio: prevent submitting more than MAX_EVENTS

2016-07-13 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.