On 03.04.24 13:48, Ryan Roberts wrote:
On 03/04/2024 09:22, David Hildenbrand wrote:
On 03.04.24 05:55, Barry Song wrote:
From: Barry Song <v-songbaohua@xxxxxxxx>
Profiling a system blindly with mTHP has become challenging due
to the lack of visibility into its operations. Presenting the
success rate of mTHP allocations appears to be pressing need.
Recently, I've been experiencing significant difficulty debugging
performance improvements and regressions without these figures.
It's crucial for us to understand the true effectiveness of
mTHP in real-world scenarios, especially in systems with
fragmented memory.
This patch sets up the framework for per-order mTHP counters,
starting with the introduction of anon_alloc_success and
anon_alloc_fail counters. Incorporating additional counters
should now be straightforward as well.
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
---
-v3:
* save some memory as order-0 and order-1 can't be THP, Ryan;
* rename to anon_alloc as right now we only support anon to address
David's comment;
* drop a redundant "else", Ryan
include/linux/huge_mm.h | 18 ++++++++++++++
mm/huge_memory.c | 54 +++++++++++++++++++++++++++++++++++++++++
mm/memory.c | 2 ++
3 files changed, 74 insertions(+)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index e896ca4760f6..5e9af6be9537 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -70,6 +70,7 @@ extern struct kobj_attribute shmem_enabled_attr;
* (which is a limitation of the THP implementation).
*/
#define THP_ORDERS_ALL_ANON ((BIT(PMD_ORDER + 1) - 1) & ~(BIT(0) | BIT(1)))
+#define THP_MIN_ORDER 2
/*
* Mask of all large folio orders supported for file THP.
@@ -264,6 +265,23 @@ unsigned long thp_vma_allowable_orders(struct
vm_area_struct *vma,
enforce_sysfs, orders);
}
+enum thp_event_item {
+ THP_ANON_ALLOC_SUCCESS,
+ THP_ANON_ALLOC_FAIL,
+ NR_THP_EVENT_ITEMS
+};
Maybe use a prefix that resembles matches the enum name and is "obviously"
different to the ones in vm_event_item.h, like
enum thp_event {
THP_EVENT_ANON_ALLOC_SUCCESS,
THP_EVENT_ANON_ALLOC_FAIL,
__THP_EVENT_COUNT,
};
FWIW, I'd personally replace "event" with "stat". For me "event" only ever
increments, but "stat" can increment and decrement. An event is a type of stat.
You are only adding events for now, but we have identified a need for inc/dec
stats that will be added in future.
Fully agree!
--
Cheers,
David / dhildenb
