I was recently going over all users of PG_reserved. Short story: it is
difficult and sometimes not really clear if setting/checking for
PG_reserved is only a relict from the past. Easy to break things. I
guess I know have a pretty good idea wh things are like that
nowadays and how they evolved.
I had way more cleanups in this series inititally,
but some architectures take PG_reserved as a way to apply a different
caching strategy (for MMIO pages). So I decided to only include the most
obvious changes (that are less likely to break something). So the big
chunk of manual SetPageReserved users are MMIO/DMA related things on
device buffers.
Most notably, for device memory we will hopefully soon stop setting
PG_reserved. The the documentation has to be updated.
RFC -> V1:
- Add more details to "mm: better document PG_reserved"
- Add "arm64: kdump: No need to mark crashkernel pages manually
PG_reserved"
- Add "ia64: perfmon: Don't mark buffer pages as PG_reserved"
- Added ACKs
David Hildenbrand (9):
agp: efficeon: no need to set PG_reserved on GATT tables
s390/vdso: don't clear PG_reserved
powerpc/vdso: don't clear PG_reserved
riscv/vdso: don't clear PG_reserved
m68k/mm: use __ClearPageReserved()
arm64: kexec: no need to ClearPageReserved()
arm64: kdump: No need to mark crashkernel pages manually PG_reserved
ia64: perfmon: Don't mark buffer pages as PG_reserved
mm: better document PG_reserved
arch/arm64/kernel/machine_kexec.c | 3 +-
arch/arm64/mm/init.c | 27 --------------
arch/ia64/kernel/perfmon.c | 59 +++----------------------------
arch/m68k/mm/memory.c | 2 +-
arch/powerpc/kernel/vdso.c | 2 --
arch/riscv/kernel/vdso.c | 1 -
arch/s390/kernel/vdso.c | 2 --
drivers/char/agp/efficeon-agp.c | 2 --
include/linux/page-flags.h | 33 +++++++++++++++--
9 files changed, 37 insertions(+), 94 deletions(-)
--
2.17.2
