The patch titled
Subject: mm, page_owner: make init_pages_in_zone() faster
has been removed from the -mm tree. Its filename was
mm-page_owner-make-init_pages_in_zone-faster.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm, page_owner: make init_pages_in_zone() faster
In init_pages_in_zone() we currently use the generic set_page_owner()
function to initialize page_owner info for early allocated pages. This
means we needlessly do lookup_page_ext() twice for each page, and more
importantly save_stack(), which has to unwind the stack and find the
corresponding stack depot handle. Because the stack is always the same
for the initialization, unwind it once in init_pages_in_zone() and reuse
the handle. Also avoid the repeated lookup_page_ext().
This can significantly reduce boot times with page_owner=on on large
machines, especially for kernels built without frame pointer, where the
stack unwinding is noticeably slower.
[vbabka@xxxxxxx: don't duplicate code of __set_page_owner(), per Michal Hocko]
[akpm@xxxxxxxxxxxxxxxxxxxx: coding-style fixes]
[vbabka@xxxxxxx: create statically allocated fake stack trace for early allocated pages, per Michal]
Link: http://lkml.kernel.org/r/45813564-2342-fc8d-d31a-f4b68a724325@xxxxxxx
Link: http://lkml.kernel.org/r/20170720134029.25268-2-vbabka@xxxxxxx
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Yang Shi <yang.shi@xxxxxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx>
Cc: zhong jiang <zhongjiang@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_owner.c | 52 ++++++++++++++++++++++++++++------------------
1 file changed, 32 insertions(+), 20 deletions(-)
diff -puN mm/page_owner.c~mm-page_owner-make-init_pages_in_zone-faster mm/page_owner.c
--- a/mm/page_owner.c~mm-page_owner-make-init_pages_in_zone-faster
+++ a/mm/page_owner.c
@@ -30,6 +30,7 @@ DEFINE_STATIC_KEY_FALSE(page_owner_inite
static depot_stack_handle_t dummy_handle;
static depot_stack_handle_t failure_handle;
+static depot_stack_handle_t early_handle;
static void init_early_allocated_pages(void);
@@ -53,7 +54,7 @@ static bool need_page_owner(void)
return true;
}
-static noinline void register_dummy_stack(void)
+static __always_inline depot_stack_handle_t create_dummy_stack(void)
{
unsigned long entries[4];
struct stack_trace dummy;
@@ -64,21 +65,22 @@ static noinline void register_dummy_stac
dummy.skip = 0;
save_stack_trace(&dummy);
- dummy_handle = depot_save_stack(&dummy, GFP_KERNEL);
+ return depot_save_stack(&dummy, GFP_KERNEL);
}
-static noinline void register_failure_stack(void)
+static noinline void register_dummy_stack(void)
{
- unsigned long entries[4];
- struct stack_trace failure;
+ dummy_handle = create_dummy_stack();
+}
- failure.nr_entries = 0;
- failure.max_entries = ARRAY_SIZE(entries);
- failure.entries = &entries[0];
- failure.skip = 0;
+static noinline void register_failure_stack(void)
+{
+ failure_handle = create_dummy_stack();
+}
- save_stack_trace(&failure);
- failure_handle = depot_save_stack(&failure, GFP_KERNEL);
+static noinline void register_early_stack(void)
+{
+ early_handle = create_dummy_stack();
}
static void init_page_owner(void)
@@ -88,6 +90,7 @@ static void init_page_owner(void)
register_dummy_stack();
register_failure_stack();
+ register_early_stack();
static_branch_enable(&page_owner_inited);
init_early_allocated_pages();
}
@@ -165,17 +168,13 @@ static noinline depot_stack_handle_t sav
return handle;
}
-noinline void __set_page_owner(struct page *page, unsigned int order,
- gfp_t gfp_mask)
+static inline void __set_page_owner_handle(struct page_ext *page_ext,
+ depot_stack_handle_t handle, unsigned int order, gfp_t gfp_mask)
{
- struct page_ext *page_ext = lookup_page_ext(page);
struct page_owner *page_owner;
- if (unlikely(!page_ext))
- return;
-
page_owner = get_page_owner(page_ext);
- page_owner->handle = save_stack(gfp_mask);
+ page_owner->handle = handle;
page_owner->order = order;
page_owner->gfp_mask = gfp_mask;
page_owner->last_migrate_reason = -1;
@@ -183,6 +182,19 @@ noinline void __set_page_owner(struct pa
__set_bit(PAGE_EXT_OWNER, &page_ext->flags);
}
+noinline void __set_page_owner(struct page *page, unsigned int order,
+ gfp_t gfp_mask)
+{
+ struct page_ext *page_ext = lookup_page_ext(page);
+ depot_stack_handle_t handle;
+
+ if (unlikely(!page_ext))
+ return;
+
+ handle = save_stack(gfp_mask);
+ __set_page_owner_handle(page_ext, handle, order, gfp_mask);
+}
+
void __set_page_owner_migrate_reason(struct page *page, int reason)
{
struct page_ext *page_ext = lookup_page_ext(page);
@@ -565,12 +577,12 @@ static void init_pages_in_zone(pg_data_t
if (unlikely(!page_ext))
continue;
- /* Maybe overraping zone */
+ /* Maybe overlapping zone */
if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))
continue;
/* Found early allocated page */
- set_page_owner(page, 0, 0);
+ __set_page_owner_handle(page_ext, early_handle, 0, 0);
count++;
}
}
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
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