[PATCH v1 0/2] sparse_init rewrite

From: Pavel Tatashin
Date: Thu Jun 28 2018 - 13:34:03 EST


In sparse_init() we allocate two large buffers to temporary hold usemap and
memmap for the whole machine. However, we can avoid doing that if we
changed sparse_init() to operated on per-node bases instead of doing it on
the whole machine beforehand.

As shown by Baoquan
http://lkml.kernel.org/r/20180628062857.29658-1-bhe@xxxxxxxxxx

The buffers are large enough to cause machine stop to boot on small memory
systems.

These patches should be applied on top of Baoquan's work, as
CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER is removed in that work.

For the ease of review, I split this work so the first patch only adds new
interfaces, the second patch enables them, and removes the old ones.

Pavel Tatashin (2):
mm/sparse: add sparse_init_nid()
mm/sparse: start using sparse_init_nid(), and remove old code

include/linux/mm.h | 9 +-
mm/sparse-vmemmap.c | 44 ++++---
mm/sparse.c | 285 ++++++++++++++------------------------------
3 files changed, 125 insertions(+), 213 deletions(-)

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2.18.0