]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
mm/page_reporting: allow driver to specify reporting order
authorGavin Shan <gshan@redhat.com>
Tue, 29 Jun 2021 02:35:22 +0000 (19:35 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 29 Jun 2021 17:53:47 +0000 (10:53 -0700)
commit9f849c6f9572d8cef407f55928d3dc68fc42ad3e
tree7a8c8c792098f1061438db886a60fe87212a38fc
parentf58780a8e3851edae5bafb7d3af19425308a37f5
mm/page_reporting: allow driver to specify reporting order

The page reporting order (threshold) is sticky to @pageblock_order by
default.  The page reporting can never be triggered because the freeing
page can't come up with a free area like that huge.  The situation becomes
worse when the system memory becomes heavily fragmented.

For example, the following configurations are used on ARM64 when 64KB base
page size is enabled.  In this specific case, the page reporting won't be
triggered until the freeing page comes up with a 512MB free area.  That's
hard to be met, especially when the system memory becomes heavily
fragmented.

   PAGE_SIZE:          64KB
   HPAGE_SIZE:         512MB
   pageblock_order:    13       (512MB)
   MAX_ORDER:          14

This allows the drivers to specify the page reporting order when the page
reporting device is registered.  It falls back to @pageblock_order if it's
not specified by the driver.  The existing users (hv_balloon and
virtio_balloon) don't specify it and @pageblock_order is still taken as
their page reporting order.  So this shouldn't introduce any functional
changes.

Link: https://lkml.kernel.org/r/20210625014710.42954-4-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/page_reporting.h
mm/page_reporting.c