Messages in this thread | | | Date | Fri, 29 Mar 2024 12:54:30 +0800 | Subject | Re: [PATCH v3 0/3] page_owner: Fix refcount imbalance | From | Kefeng Wang <> |
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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(-) >
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