[0/2] Fix the incorrect memmap init defer handling

Message

Baoquan He Dec. 13, 2020, 3:09 p.m. UTC

VMware reported the performance regression during memmap_init() invocation.
And they bisected to commit 73a6e474cb376 ("mm: memmap_init: iterate over
memblock regions rather that check each PFN") causing it.

After investigation, it's caused by incorrect memmap init defer handling
in memmap_init_zone() after commit 73a6e474cb376. The current
memmap_init_zone() only handle one memory region of one zone, while
memmap_init() iterates over all its memory regions and pass them one by
one into memmap_init_zone() to handle.

So in this patchset, patch 1/2 fixes the bug observed by VMware. Patch
2/2 clean up the inappropriate name of memmap_init(), memmap_init_zone()
accordingly.

VMware helped do the testing on their VMware ESI platform. This patchset
is based on 5.10.0-rc7+, master branch of Linus's tree.

Baoquan He (2):
  mm: memmap defer init dosn't work as expected
  mm: rename memmap_init() and memmap_init_zone()

 arch/ia64/mm/init.c |  8 ++++----
 include/linux/mm.h  |  5 +++--
 mm/memory_hotplug.c |  2 +-
 mm/page_alloc.c     | 22 ++++++++++++----------
 4 files changed, 20 insertions(+), 17 deletions(-)