tree de4b214ccd0de78d9dab8b960efe12ee46ebaa2f
parent 36df7ddfa6045507a1c9391a24c32ef33c5a0798
author Baoquan He <bhe@redhat.com> 1530694998 +0200
committer Michal Hocko <mhocko@suse.com> 1530695019 +0200

mm/sparsemem.c: defer the ms->section_mem_map clearing

In sparse_init(), if CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER=y, system
will allocate one continuous memory chunk for mem maps on one node and
populate the relevant page tables to map memory section one by one.  If
fail to populate for a certain mem section, print warning and its
->section_mem_map will be cleared to cancel the marking of being present.
Like this, the number of mem sections marked as present could become less
during sparse_init() execution.

Here just defer the ms->section_mem_map clearing if failed to populate its
page tables until the last for_each_present_section_nr() loop.  This is in
preparation for later optimizing the mem map allocation.

Link: http://lkml.kernel.org/r/20180228032657.32385-3-bhe@redhat.com
[akpm: remove now-unused local `ms', per Oscar]
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>