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authorVijay Balakrishna <vijayb@linux.microsoft.com>2020-10-10 23:16:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-11 10:31:11 -0700
commit4aab2be0983031a05cb4a19696c9da5749523426 (patch)
treefdcd0839b793970a43c03f3201c0878ccc4cd611
parent8b7b2eb131d3476062ffd34358785b44be25172f (diff)
mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected by khugepaged
When memory is hotplug added or removed the min_free_kbytes should be recalculated based on what is expected by khugepaged. Currently after hotplug, min_free_kbytes will be set to a lower default and higher default set when THP enabled is lost. This change restores min_free_kbytes as expected for THP consumers. [vijayb@linux.microsoft.com: v5] Link: https://lkml.kernel.org/r/1601398153-5517-1-git-send-email-vijayb@linux.microsoft.com Fixes: f000565adb77 ("thp: set recommended min free kbytes") Signed-off-by: Vijay Balakrishna <vijayb@linux.microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Allen Pais <apais@microsoft.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Song Liu <songliubraving@fb.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/1600305709-2319-2-git-send-email-vijayb@linux.microsoft.com Link: https://lkml.kernel.org/r/1600204258-13683-1-git-send-email-vijayb@linux.microsoft.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/khugepaged.h5
-rw-r--r--mm/khugepaged.c13
-rw-r--r--mm/page_alloc.c3
3 files changed, 19 insertions, 2 deletions
diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h
index bc45ea1efbf7..c941b7377321 100644
--- a/include/linux/khugepaged.h
+++ b/include/linux/khugepaged.h
@@ -15,6 +15,7 @@ extern int __khugepaged_enter(struct mm_struct *mm);
extern void __khugepaged_exit(struct mm_struct *mm);
extern int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
unsigned long vm_flags);
+extern void khugepaged_min_free_kbytes_update(void);
#ifdef CONFIG_SHMEM
extern void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr);
#else
@@ -85,6 +86,10 @@ static inline void collapse_pte_mapped_thp(struct mm_struct *mm,
unsigned long addr)
{
}
+
+static inline void khugepaged_min_free_kbytes_update(void)
+{
+}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif /* _LINUX_KHUGEPAGED_H */
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 3a494cfa56d2..58b0d9c502a1 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -56,6 +56,9 @@ enum scan_result {
#define CREATE_TRACE_POINTS
#include <trace/events/huge_memory.h>
+static struct task_struct *khugepaged_thread __read_mostly;
+static DEFINE_MUTEX(khugepaged_mutex);
+
/* default scan 8*512 pte (or vmas) every 30 second */
static unsigned int khugepaged_pages_to_scan __read_mostly;
static unsigned int khugepaged_pages_collapsed;
@@ -2304,8 +2307,6 @@ static void set_recommended_min_free_kbytes(void)
int start_stop_khugepaged(void)
{
- static struct task_struct *khugepaged_thread __read_mostly;
- static DEFINE_MUTEX(khugepaged_mutex);
int err = 0;
mutex_lock(&khugepaged_mutex);
@@ -2332,3 +2333,11 @@ fail:
mutex_unlock(&khugepaged_mutex);
return err;
}
+
+void khugepaged_min_free_kbytes_update(void)
+{
+ mutex_lock(&khugepaged_mutex);
+ if (khugepaged_enabled() && khugepaged_thread)
+ set_recommended_min_free_kbytes();
+ mutex_unlock(&khugepaged_mutex);
+}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6866533de8e6..780c8f023b28 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -69,6 +69,7 @@
#include <linux/nmi.h>
#include <linux/psi.h>
#include <linux/padata.h>
+#include <linux/khugepaged.h>
#include <asm/sections.h>
#include <asm/tlbflush.h>
@@ -7904,6 +7905,8 @@ int __meminit init_per_zone_wmark_min(void)
setup_min_slab_ratio();
#endif
+ khugepaged_min_free_kbytes_update();
+
return 0;
}
postcore_initcall(init_per_zone_wmark_min)