On 02.04.24 23:29, Barry Song wrote:
On Wed, Apr 3, 2024 at 7:46 AM David Hildenbrand <david@xxxxxxxxxx> wrote:
On 28.03.24 10:51, 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 alloc_success and alloc_fail
counters. Incorporating additional counters should now be
straightforward as well.
The initial two unsigned longs for each event are unused, given
that order-0 and order-1 are not mTHP. Nonetheless, this refinement
improves code clarity.
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
---
-v2:
* move to sysfs and provide per-order counters; David, Ryan, Willy
-v1:
https://lore.kernel.org/linux-mm/20240326030103.50678-1-21cnbao@xxxxxxxxx/
include/linux/huge_mm.h | 17 +++++++++++++
mm/huge_memory.c | 54 +++++++++++++++++++++++++++++++++++++++++
mm/memory.c | 3 +++
3 files changed, 74 insertions(+)
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index e896ca4760f6..27fa26a22a8f 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -264,6 +264,23 @@ unsigned long thp_vma_allowable_orders(struct vm_area_struct *vma,
enforce_sysfs, orders);
}
+enum thp_event_item {
+ THP_ALLOC_SUCCESS,
+ THP_ALLOC_FAIL,
+ NR_THP_EVENT_ITEMS
+};
Why not simply "enum thp_event" ... "NR_THP_EVENT".
I'm wondering if these should be ANON specific for now. We might want to
add others (shmem, file) in the future.
I've two ways to do that
1. rename to ANON_THP_ALLOC, so that I can have SHMEM_THP_ALLOC, FILE_THP_ALLOC
in the future;
2. let THP_ALLOC cover all of shmem, file and anon.
following vmstat, actually 1 might be better as we have both THP_FAULT_ALLOC and
THP_FILE_ALLOC for pmd-mapped THP.
Yes. Because anon was first, people just named it "THP". Then, file THP
were added later. Some of that needs a cleanup.
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
THP_FAULT_ALLOC,
THP_FAULT_FALLBACK,
THP_FAULT_FALLBACK_CHARGE,
THP_COLLAPSE_ALLOC,
THP_COLLAPSE_ALLOC_FAILED,
THP_FILE_ALLOC,
THP_FILE_FALLBACK,
THP_FILE_FALLBACK_CHARGE,
THP_FILE_MAPPED,
THP_SPLIT_PAGE,
THP_SPLIT_PAGE_FAILED,
THP_DEFERRED_SPLIT_PAGE,
THP_SPLIT_PMD,
THP_SCAN_EXCEED_NONE_PTE,
THP_SCAN_EXCEED_SWAP_PTE,
THP_SCAN_EXCEED_SHARED_PTE,
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
THP_SPLIT_PUD,
#endif
THP_ZERO_PAGE_ALLOC,
THP_ZERO_PAGE_ALLOC_FAILED,
THP_SWPOUT,
THP_SWPOUT_FALLBACK,
#endif
And reading mm/shmem.c, obviously, shmem is using THP_FILE_ALLOC.
Right.
I will rename it to ANON_THP_ALLOC in v3, let me know if you disagree :-)
You should give people more time to respond before resending. Please try
sending new versions only after the discussion on the old version
finished. Otherwise it's going to be a mess (because I won't repost my
feedback to v3 :P ).
THP_EVENT_ANON_ALLOC
might be better, so "THP_EVENT" would be your common prefix for "enum
thp_event".
--
Cheers,
David / dhildenb
