diff mbox series

+ mm-khugepaged-avoid-overriding-min_free_kbytes-set-by-user.patch added to -mm tree

Message ID 20200925025156.Q7pMC%akpm@linux-foundation.org
State New
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Series + mm-khugepaged-avoid-overriding-min_free_kbytes-set-by-user.patch added to -mm tree | expand

Commit Message

Andrew Morton Sept. 25, 2020, 2:51 a.m. UTC 
The patch titled
     Subject: mm: khugepaged: avoid overriding min_free_kbytes set by user
has been added to the -mm tree.  Its filename is
     mm-khugepaged-avoid-overriding-min_free_kbytes-set-by-user.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-khugepaged-avoid-overriding-min_free_kbytes-set-by-user.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-khugepaged-avoid-overriding-min_free_kbytes-set-by-user.patch

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------------------------------------------------------
From: Vijay Balakrishna <vijayb@linux.microsoft.com>
Subject: mm: khugepaged: avoid overriding min_free_kbytes set by user

set_recommended_min_free_kbytes need to honor min_free_kbytes set by the
user.  Post start-of-day THP enable or memory hotplug operations can lose
user specified min_free_kbytes, in particular when it is higher than
calculated recommended value.  user_min_free_kbytes initialized to 0 to
avoid undesired result when comparing with "unsigned long" type.

Link: https://lkml.kernel.org/r/1600305709-2319-3-git-send-email-vijayb@linux.microsoft.com
Signed-off-by: Vijay Balakrishna <vijayb@linux.microsoft.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Allen Pais <apais@microsoft.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/khugepaged.c |    3 ++-
 mm/page_alloc.c |    2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

--- a/mm/khugepaged.c~mm-khugepaged-avoid-overriding-min_free_kbytes-set-by-user
+++ a/mm/khugepaged.c
@@ -2283,7 +2283,8 @@  static void set_recommended_min_free_kby
 			      (unsigned long) nr_free_buffer_pages() / 20);
 	recommended_min <<= (PAGE_SHIFT-10);
 
-	if (recommended_min > min_free_kbytes) {
+	if (recommended_min > min_free_kbytes ||
+		recommended_min > user_min_free_kbytes) {
 		if (user_min_free_kbytes >= 0)
 			pr_info("raising min_free_kbytes from %d to %lu to help transparent hugepage allocations\n",
 				min_free_kbytes, recommended_min);
--- a/mm/page_alloc.c~mm-khugepaged-avoid-overriding-min_free_kbytes-set-by-user
+++ a/mm/page_alloc.c
@@ -315,7 +315,7 @@  compound_page_dtor * const compound_page
 };
 
 int min_free_kbytes = 1024;
-int user_min_free_kbytes = -1;
+int user_min_free_kbytes = 0;
 #ifdef CONFIG_DISCONTIGMEM
 /*
  * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges