On 2024/3/26 14:30, Oscar Salvador wrote:
This series consists of a refactoring/correctness of updating the metadata
of tail pages and a couple of fixups for the refcounting part.
From this series on, instead of counting the stacks, we count the outstanding
nr_base_pages each stack has, which gives us a much better memory overview.
The other fixup is for the migration part.
A more detailed explanation can be found in the changelog of the respective
patches.
Hi Oscar, this patchset fix the following issue when I test my migration
changes, but
[ 31.478715] ------------[ cut here ]------------
[ 31.480491] refcount_t: decrement hit 0; leaking memory.
[ 31.482724] WARNING: CPU: 7 PID: 113 at lib/refcount.c:31
refcount_warn_saturate+0x13c/0x148
[ 31.485390] Modules linked in:
[ 31.486800] CPU: 7 PID: 113 Comm: sh Not tainted
6.9.0-rc1-00178-g317c7bc0ef03 #139
[ 31.487883] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0
02/06/2015
[ 31.489066] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS
BTYPE=--)
[ 31.489872] pc : refcount_warn_saturate+0x13c/0x148
[ 31.490350] lr : refcount_warn_saturate+0x13c/0x148
[ 31.490829] sp : ffff800087913650
[ 31.491182] x29: ffff800087913650 x28: ffff00020624d010 x27:
0000000000000000
[ 31.492419] x26: 0000000000000001 x25: ffff800082dd0d60 x24:
0000000000000000
[ 31.493006] x23: 0000000754405c20 x22: ffff800082ec0000 x21:
00000000028c008e
[ 31.493527] x20: ffff0000d1638208 x19: ffff0000d1638200 x18:
0000000000000010
[ 31.493984] x17: 0000000000000006 x16: 0000000000000000 x15:
ffff0000c6253c18
[ 31.494330] x14: 0000000000000000 x13: 0000000000000002 x12:
ffff800082dff318
[ 31.494669] x11: ffff800082e6f640 x10: ffff800082e57600 x9 :
ffff80008015869c
[ 31.495056] x8 : 0000000000017fe8 x7 : c0000000ffffefff x6 :
0000000000000001
[ 31.495383] x5 : 0000000000057fa8 x4 : 0000000000000000 x3 :
0000000000000000
[ 31.495756] x2 : ffff800082dff228 x1 : 0000000000000000 x0 :
0000000000000000
[ 31.496367] Call trace:
[ 31.496528] refcount_warn_saturate+0x13c/0x148
[ 31.496760] __reset_page_owner+0x124/0x158
[ 31.496965] free_unref_page_prepare+0x2a4/0x440
[ 31.497183] free_unref_folios+0x118/0x460
[ 31.497368] folios_put_refs+0x11c/0x250
[ 31.497559] free_pages_and_swap_cache+0xd4/0x160
[ 31.497772] tlb_flush_mmu+0x8c/0x188
[ 31.497952] tlb_finish_mmu+0x54/0x160
[ 31.498123] exit_mmap+0x174/0x4e8
[ 31.498295] mmput+0xb4/0x1a0
[ 31.498429] begin_new_exec+0x474/0xd30
[ 31.498606] load_elf_binary+0x378/0x1488
[ 31.498792] bprm_execve+0x2a0/0x7e0
[ 31.498956] do_execveat_common.isra.0+0x19c/0x240
[ 31.499174] __arm64_sys_execve+0x48/0x68
[ 31.499358] invoke_syscall+0x4c/0x118
[ 31.499534] el0_svc_common.constprop.0+0x48/0xf0
[ 31.499816] do_el0_svc+0x24/0x38
[ 31.500063] el0_svc+0x4c/0x120
[ 31.500314] el0t_64_sync_handler+0xc0/0xc8
[ 31.500584] el0t_64_sync+0x190/0x198
I still see the following memory leak, could you check it?
/mnt/arm64 # cat /sys//kernel/debug/kmemleak
unreferenced object 0xffff000200d91000 (size 16):
comm "kworker/4:0", pid 42, jiffies 4294892753
hex dump (first 16 bytes):
60 37 57 c1 00 00 ff ff 00 00 00 00 00 00 00 00 `7W.............
backtrace (crc 4458f477):
[<(____ptrval____)>] kmemleak_alloc+0x3c/0x50
[<(____ptrval____)>] kmalloc_trace+0x20c/0x2e0
[<(____ptrval____)>] __set_page_owner+0x1d0/0x2a0
[<(____ptrval____)>] prep_new_page+0x108/0x138
[<(____ptrval____)>] get_page_from_freelist+0x79c/0x16b8
[<(____ptrval____)>] __alloc_pages+0x1bc/0x440
[<(____ptrval____)>] new_slab+0x104/0x3c8
[<(____ptrval____)>] ___slab_alloc+0x368/0xb20
[<(____ptrval____)>] __slab_alloc.isra.0+0x3c/0x88
[<(____ptrval____)>] kmalloc_trace+0x280/0x2e0
[<(____ptrval____)>] __set_page_owner+0x1d0/0x2a0
[<(____ptrval____)>] prep_new_page+0x108/0x138
[<(____ptrval____)>] get_page_from_freelist+0x79c/0x16b8
[<(____ptrval____)>] __alloc_pages+0x1bc/0x440
[<(____ptrval____)>] new_slab+0x104/0x3c8
[<(____ptrval____)>] ___slab_alloc+0x368/0xb20
unreferenced object 0xffff000200d90000 (size 16):
comm "kworker/4:0", pid 42, jiffies 4294892753
hex dump (first 16 bytes):
20 38 57 c1 00 00 ff ff 00 10 d9 00 02 00 ff ff 8W.............
backtrace (crc 786eca4d):
[<(____ptrval____)>] kmemleak_alloc+0x3c/0x50
[<(____ptrval____)>] kmalloc_trace+0x20c/0x2e0
[<(____ptrval____)>] __set_page_owner+0x1d0/0x2a0
[<(____ptrval____)>] prep_new_page+0x108/0x138
[<(____ptrval____)>] get_page_from_freelist+0x79c/0x16b8
[<(____ptrval____)>] __alloc_pages+0x1bc/0x440
[<(____ptrval____)>] new_slab+0x104/0x3c8
[<(____ptrval____)>] ___slab_alloc+0x368/0xb20
[<(____ptrval____)>] __slab_alloc.isra.0+0x3c/0x88
[<(____ptrval____)>] kmalloc_node_trace+0x274/0x2f0
[<(____ptrval____)>] alloc_worker+0x2c/0x70
[<(____ptrval____)>] create_worker+0x58/0x278
[<(____ptrval____)>] worker_thread+0x260/0x320
[<(____ptrval____)>] kthread+0x130/0x148
[<(____ptrval____)>] ret_from_fork+0x10/0x20
unreferenced object 0xffff000200d90010 (size 16):
comm "kworker/4:0", pid 42, jiffies 4294892753
hex dump (first 16 bytes):
e0 39 57 c1 00 00 ff ff 00 00 d9 00 02 00 ff ff .9W.............
backtrace (crc d4c89665):
[<(____ptrval____)>] kmemleak_alloc+0x3c/0x50
[<(____ptrval____)>] kmalloc_trace+0x20c/0x2e0
[<(____ptrval____)>] __set_page_owner+0x1d0/0x2a0
[<(____ptrval____)>] prep_new_page+0x108/0x138
[<(____ptrval____)>] get_page_from_freelist+0x79c/0x16b8
[<(____ptrval____)>] __alloc_pages+0x1bc/0x440
[<(____ptrval____)>] new_slab+0x104/0x3c8
[<(____ptrval____)>] ___slab_alloc+0x368/0xb20
[<(____ptrval____)>] __slab_alloc.isra.0+0x3c/0x88
[<(____ptrval____)>] kmalloc_trace+0x280/0x2e0
[<(____ptrval____)>] __kthread_create_on_node+0x7c/0x190
[<(____ptrval____)>] kthread_create_on_node+0x60/0x90
[<(____ptrval____)>] create_worker+0xd0/0x278
[<(____ptrval____)>] worker_thread+0x260/0x320
[<(____ptrval____)>] kthread+0x130/0x148
[<(____ptrval____)>] ret_from_fork+0x10/0x20
Thanks.
Oscar Salvador (3):
mm,page_owner: Update metada for tail pages
mm,page_owner: Fix refcount imbalance
mm,page_owner: Fix accounting of pages when migrating
Documentation/mm/page_owner.rst | 73 +++++++------
mm/page_owner.c | 184 +++++++++++++++++++-------------
2 files changed, 146 insertions(+), 111 deletions(-)
