Re: [PATCH] mm: cma: support sysfs

[John Hubbard]

On 2/5/21 1:52 PM, Suren Baghdasaryan wrote:
> > > > I takes your suggestion something like this.
> > > >
> > > > [alloc_range] could be order or range by interval
> > > >
> > > > /sys/kernel/mm/cma/cma-A/[alloc_range]/success
> > > > /sys/kernel/mm/cma/cma-A/[alloc_range]/fail
> > > > ..
> > > > ..
> > > > /sys/kernel/mm/cma/cma-Z/[alloc_range]/success
> > > > /sys/kernel/mm/cma/cma-Z/[alloc_range]/fail
>
> The interface above seems to me the most useful actually, if by
> [alloc_range] you mean the different allocation orders. This would
> cover Minchan's per-CMA failure tracking and would also allow us to
> understand what kind of allocations are failing and therefore if the
> problem is caused by pinning/fragmentation or by over-utilization.

I agree. That seems about right, now that we've established that
cma areas are a must-have.

thanks,
--
John Hubbard
NVIDIA