linux/kernel/liveupdate
Pratyush Yadav 22bdab8e98 kho: drop restriction on maximum page order
KHO currently restricts the maximum order of a restored page to the
maximum order supported by the buddy allocator.  While this works fine for
much of the data passed across kexec, it is possible to have pages larger
than MAX_PAGE_ORDER.

For one, it is possible to get a larger order when using
kho_preserve_pages() if the number of pages is large enough, since it
tries to combine multiple aligned 0-order preservations into one higher
order preservation.

For another, upcoming support for hugepages can have gigantic hugepages
being preserved over KHO.

There is no real reason for this limit.  The KHO preservation machinery
can handle any page order.  Remove this artificial restriction on max page
order.

Link: https://lkml.kernel.org/r/20260309123410.382308-2-pratyush@kernel.org
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Samiullah Khawaja <skhawaja@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05 13:53:24 -07:00
..
Kconfig liveupdate: separate memfd support into LIVEUPDATE_MEMFD 2026-01-26 19:07:10 -08:00
kexec_handover_debug.c
kexec_handover_debugfs.c kho: remove finalize state and clients 2026-04-05 13:53:04 -07:00
kexec_handover_internal.h kho: remove finalize state and clients 2026-04-05 13:53:04 -07:00
kexec_handover.c kho: drop restriction on maximum page order 2026-04-05 13:53:24 -07:00
luo_core.c kho: remove finalize state and clients 2026-04-05 13:53:04 -07:00
luo_file.c liveupdate: luo_file: remember retrieve() status 2026-02-24 11:13:26 -08:00
luo_flb.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
luo_internal.h tests/liveupdate: add in-kernel liveupdate test 2026-02-08 00:13:33 -08:00
luo_session.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
Makefile liveupdate: luo_flb: introduce File-Lifecycle-Bound global state 2026-02-08 00:13:33 -08:00