On Fri, Feb 05, 2021 at 01:58:06PM -0800, John Hubbard wrote:

On 2/5/21 1:52 PM, Suren Baghdasaryan wrote:

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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.

Okay, now we agreed the dirction right now so let me do that in next
version. If you don't see it's reasonable, let me know.

* I will drop the number of CMA *page* allocation attemtps/failures to
make simple start
* I will keep CMA allocation attemtps/failures
* They will be under /sys/kernel/mm/cma/cma-XX/success,fail
* It will turn on CONFIG_CMA && CONFIG_SYSFS

Orthognal work(diffrent patchset)

* adding global CMA alloc/fail into vmstat
* adding alloc_range success/failure under CONFIG_CMA_ALLOC_TRACKING
  whatever configuration or just by default if everyone agree

Thanks.