Re: [RFC PATCH v2 3/3] android: ion: include system heap size in meminfo extra

On Mon, Mar 23, 2020 at 05:05:03PM +0900, Jaewon Kim wrote:

In Android system ion system heap size is huge like hundreds of MB. To
know overal system memory usage, include ion system heap size in
proc/meminfo_extra.

To include heap size, use register_meminfo_extra introduced in previous
patch.

Prior to register we need to add stats to show the ion heap usage. Add
total_allocated into ion heap and count it on allocation and freeing. In
a ion heap using ION_HEAP_FLAG_DEFER_FREE, a buffer can be freed from
user but still live on deferred free list. Keep stats until the buffer
is finally freed so that we can cover situation of deferred free thread
stuck problem.

i.e) cat /proc/meminfo_extra | grep IonSystemHeap
IonSystemHeap:    242620 kB

i.e.) show_mem on oom
<6>[  420.856428]  Mem-Info:
<6>[  420.856433]  IonSystemHeap:32813kB

Signed-off-by: Jaewon Kim <redacted>
---
 drivers/staging/android/ion/ion.c             | 2 ++
 drivers/staging/android/ion/ion.h             | 1 +
 drivers/staging/android/ion/ion_system_heap.c | 2 ++
 3 files changed, 5 insertions(+)

Does this really give the proper granularity that ion users have?  I
thought they wanted to know what each heap was doing.

Also, this code should be deleted really soon now, so I would not make
any core changes to the kernel based on it at all.

thanks,

greg k-h