Re: [Intel-wired-lan] Increased memory usage on NUMA nodes with ICE driver after upgrade to 6.13.y (regression in commit 492a044508ad)

[Jacob Keller <jacob.e.keller@intel.com>]

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On 7/2/2025 2:48 AM, Jaroslav Pulchart wrote:
>>
>> On 6/30/2025 11:48 PM, Jaroslav Pulchart wrote:
>>>> On 6/30/2025 2:56 PM, Jacob Keller wrote:
>>>>> Unfortunately it looks like the fix I mentioned has landed in 6.14, so
>>>>> its not a fix for your issue (since you mentioned 6.14 has failed
>>>>> testing in your system)
>>>>>
>>>>> $ git describe --first-parent --contains --match=v* --exclude=*rc*
>>>>> 743bbd93cf29f653fae0e1416a31f03231689911
>>>>> v6.14~251^2~15^2~2
>>>>>
>>>>> I don't see any other relevant changes since v6.14. I can try to see if
>>>>> I see similar issues with CONFIG_MEM_ALLOC_PROFILING on some test
>>>>> systems here.
>>>>
>>>> On my system I see this at boot after loading the ice module from
>>>>
>>>> $ grep -F "/ice/" /proc/allocinfo | sort -g | tail | numfmt --to=iec>
>>>>       26K      230 drivers/net/ethernet/intel/ice/ice_irq.c:84 [ice]
>>>> func:ice_get_irq_res
>>>>>          48K        2 drivers/net/ethernet/intel/ice/ice_arfs.c:565 [ice] func:ice_init_arfs
>>>>>          57K      226 drivers/net/ethernet/intel/ice/ice_lib.c:397 [ice] func:ice_vsi_alloc_ring_stats
>>>>>          57K      226 drivers/net/ethernet/intel/ice/ice_lib.c:416 [ice] func:ice_vsi_alloc_ring_stats
>>>>>          85K      226 drivers/net/ethernet/intel/ice/ice_lib.c:1398 [ice] func:ice_vsi_alloc_rings
>>>>>         339K      226 drivers/net/ethernet/intel/ice/ice_lib.c:1422 [ice] func:ice_vsi_alloc_rings
>>>>>         678K      226 drivers/net/ethernet/intel/ice/ice_base.c:109 [ice] func:ice_vsi_alloc_q_vector
>>>>>         1.1M      257 drivers/net/ethernet/intel/ice/ice_fwlog.c:40 [ice] func:ice_fwlog_alloc_ring_buffs
>>>>>         7.2M      114 drivers/net/ethernet/intel/ice/ice_txrx.c:493 [ice] func:ice_setup_rx_ring
>>>>>         896M   229264 drivers/net/ethernet/intel/ice/ice_txrx.c:680 [ice] func:ice_alloc_mapped_page
>>>>
>>>> Its about 1GB for the mapped pages. I don't see any increase moment to
>>>> moment. I've started an iperf session to simulate some traffic, and I'll
>>>> leave this running to see if anything changes overnight.
>>>>
>>>> Is there anything else that you can share about the traffic setup or
>>>> otherwise that I could look into?  Your system seems to use ~2.5 x the
>>>> buffer size as mine, but that might just be a smaller number of CPUs.
>>>>
>>>> Hopefully I'll get some more results overnight.
>>>
>>> The traffic is random production workloads from VMs, using standard
>>> Linux or OVS bridges. There is no specific pattern to it. I haven’t
>>> had any luck reproducing (or was not patient enough) this with iperf3
>>> myself. The two active (UP) interfaces are in an LACP bonding setup.
>>> Here are our ethtool settings for the two member ports (em1 and p3p1)
>>>
>>
>> I had iperf3 running overnight and the memory usage for
>> ice_alloc_mapped_pages is constant here. Mine was direct connections
>> without bridge or bonding. From your description I assume there's no XDP
>> happening either.
> 
> Yes, no XDP in use.
> 
> BTW the allocinfo after 6days uptime:
> # uptime ; sort -g /proc/allocinfo| tail -n 15
>  11:46:44 up 6 days,  2:18,  1 user,  load average: 9.24, 11.33, 15.07
>    102489024   533797 fs/dcache.c:1681 func:__d_alloc
>    106229760    25935 mm/shmem.c:1854 func:shmem_alloc_folio
>    117118192   103097 fs/ext4/super.c:1388 [ext4] func:ext4_alloc_inode
>    134479872    32832 kernel/events/ring_buffer.c:811 func:perf_mmap_alloc_page
>    162783232     7656 mm/slub.c:2452 func:alloc_slab_page
>    189906944    46364 mm/memory.c:1056 func:folio_prealloc
>    499384320   121920 mm/percpu-vm.c:95 func:pcpu_alloc_pages
>    530579456   129536 mm/page_ext.c:271 func:alloc_page_ext
>    625876992    54186 mm/slub.c:2450 func:alloc_slab_page
>    838860800      400 mm/huge_memory.c:1165 func:vma_alloc_anon_folio_pmd
>   1014710272   247732 mm/filemap.c:1978 func:__filemap_get_folio
>   1056710656   257986 mm/memory.c:1054 func:folio_prealloc
>   1279262720      610 mm/khugepaged.c:1084 func:alloc_charge_folio
>   1334530048   325763 mm/readahead.c:186 func:ractl_alloc_folio
>   3341238272   412215 drivers/net/ethernet/intel/ice/ice_txrx.c:681
> [ice] func:ice_alloc_mapped_page
> 
I have a suspicion that the issue is related to the updating of
page_count in ice_get_rx_pgcnt(). The i40e driver has a very similar
logic for page reuse but doesn't do this. It also has a counter to track
failure to re-use the Rx pages.

Commit 11c4aa074d54 ("ice: gather page_count()'s of each frag right
before XDP prog call") changed the logic to update page_count of the Rx
page just prior to the XDP call instead of at the point where we get the
page from ice_get_rx_buf(). I think this change was originally
introduced while we were trying out an experimental refactor of the
hotpath to handle fragments differently, which no longer happens since
743bbd93cf29 ("ice: put Rx buffers after being done with current
frame"), which ironically was part of this very same series..

I think this updating of page count is accidentally causing us to
miscount when we could perform page-reuse, and ultimately causes us to
leak the page somehow. I'm still investigating, but I think this might
trigger if somehow the page pgcnt - pagecnt_bias becomes >1, we don't
reuse the page.

The i40e driver stores the page count in i40e_get_rx_buffer, and I think
our updating it later can somehow get things out-of-sync.

Do you know if your traffic pattern happens to send fragmented frames? I
think iperf doesn't do that, which might be part of whats causing this
issue. I'm going to try to see if I can generate such fragmentation to
confirm. Is your MTU kept at the default ethernet size?

At the very least I'm going to propose a patch for ice similar to the
one from Joe Damato to track the rx busy page count. That might at least
help track something..

Thanks,
Jake

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