Based on discussion with Miaohe Lin [1]. There are various places where the K(x) macro is defined, sometimes under different names, sometimes it is just open-coded. In this RFC I suggest providing a common K(x) definition that replaces existing ones. For that, a new header, mm_tools.h, is created. I couldn't find a more appropriate place for K(x). Probably, an existing header like mm_inline.h would work as well. I tried placing this macro under mm.h, but then it conflicts with uapi/linux/keyboard.h. In case this approach is acceptable, replacing open-coded variants would be done in a separate patch. For now, I'm using `git grep -nE '<<\s?\(PAGE_SHIFT\s?\-\s?10\)'` to find such places. Also note, here I do not touch files under arch/ like arch/arc/include/asm/arcregs.h where PAGES_TO_KB() is defined, or arch/powerpc/platforms/pseries/cmm.c with PAGES2KB() as well as arch/s390/appldata/appldata_mem.c with P2K() as I'm not sure if it is appropriate to include another header file there. The patch is based on top of next-20210831 and is compile-tested using allyesconfig. Please let me know what you think. Thanks. [1] https://lore.kernel.org/linux-mm/9161665.bUqNH3lxUD@xxxxxxxxxxxxxx/ Oleksandr Natalenko (1): mm: provide one common K(x) macro drivers/base/node.c | 2 +- drivers/scsi/mpt3sas/mpt3sas_base.c | 5 ++--- drivers/xen/xen-balloon.c | 11 +++++------ include/linux/mm_tools.h | 9 +++++++++ include/trace/events/writeback.h | 19 +++++++++---------- kernel/debug/kdb/kdb_main.c | 2 +- mm/backing-dev.c | 3 +-- mm/memcontrol.c | 2 +- mm/oom_kill.c | 3 +-- mm/page_alloc.c | 3 +-- 10 files changed, 31 insertions(+), 28 deletions(-) create mode 100644 include/linux/mm_tools.h -- 2.33.0
