On Thu, Jun 23, 2016 at 12:05:17PM +0200, Arnd Bergmann wrote:

I see some new warnings from a recent mm change:

mm/filemap.c: In function '__delete_from_page_cache':
include/linux/vmstat.h:116:2: error: array subscript is above array bounds [-Werror=array-bounds]
  atomic_long_add(x, &zone->vm_stat[item]);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/vmstat.h:116:35: error: array subscript is above array bounds [-Werror=array-bounds]
  atomic_long_add(x, &zone->vm_stat[item]);
                      ~~~~~~~~~~~~~^~~~~~
include/linux/vmstat.h:116:35: error: array subscript is above array bounds [-Werror=array-bounds]
include/linux/vmstat.h:117:2: error: array subscript is above array bounds [-Werror=array-bounds]

Looking deeper into it, I find that we pass the wrong enum
into some functions after the type for the symbol has changed.

This changes the code to use the other function for those that
are using the incorrect type. I've done this blindly just going
by warnings I got from a debug patch I did for this, so it's likely
that some cases are more subtle and need another change, so please
treat this as a bug-report rather than a patch for applying.

I have an alternative fix for this in a private tree. For now, I've asked
Andrew to withdraw the series entirely as there are non-trivial collisions
with OOM detection rework and huge page support for tmpfs.  It'll be easier
and safer to resolve this outside of mmotm as it'll require a full round
of testing which takes 3-4 days.

Thanks.

-- 
Mel Gorman
SUSE Labs

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