+ mm-mark-idle-page-tracking-as-broken.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: mm: mark idle page tracking as BROKEN
has been added to the -mm tree.  Its filename is
     mm-mark-idle-page-tracking-as-broken.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-mark-idle-page-tracking-as-broken.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-mark-idle-page-tracking-as-broken.patch

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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: mm: mark idle page tracking as BROKEN

In discussion with other MM developers around how idle page tracking
should be fixed for transparent huge pages, several expressed the opinion
that it should be removed as it is inefficient at accomplishing the job
that it is supposed to, and we have better mechanisms (eg uffd) for
accomplishing the same goals these days.

Mark the feature as BROKEN for now and we can remove it entirely in a few
months if nobody complains.  It is not enabled by Android, ChromeOS,
Debian, Fedora or SUSE.  Red Hat enabled it with RHEL-8.1 and UEK followed
suit, but I have been unable to find why RHEL enabled it.

Link: https://lkml.kernel.org/r/20210612000714.775825-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Yu Zhao <yuzhao@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
SeongJae Park <sj38.park@gmail.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/Kconfig~mm-mark-idle-page-tracking-as-broken
+++ a/mm/Kconfig
@@ -772,7 +772,7 @@ config DEFERRED_STRUCT_PAGE_INIT
 
 config IDLE_PAGE_TRACKING
 	bool "Enable idle page tracking"
-	depends on SYSFS && MMU
+	depends on SYSFS && MMU && BROKEN
 	select PAGE_EXTENSION if !64BIT
 	help
 	  This feature allows to estimate the amount of user pages that have
_

Patches currently in -mm which might be from willy@infradead.org are

mm-mark-idle-page-tracking-as-broken.patch
mm-make-__dump_page-static.patch
mm-debug-factor-pagepoisoned-out-of-__dump_page.patch
mm-page_owner-constify-dump_page_owner.patch
mm-make-compound_head-const-preserving.patch
mm-constify-get_pfnblock_flags_mask-and-get_pfnblock_migratetype.patch
mm-constify-page_count-and-page_ref_count.patch
mm-optimise-nth_page-for-contiguous-memmap.patch