Re: [PATCH] net: skbuff: allocate the fclone in the current NUMA node

Shijie Huang
2024-02-20T08:37:34Z

在 2024/2/20 16:17, Eric Dumazet 写道:
> On Tue, Feb 20, 2024 at 7:26 AM Shijie Huang
> <shijie@amperemail.onmicrosoft.com> wrote:
>>
>> 在 2024/2/20 13:32, Eric Dumazet 写道:
>>> On Tue, Feb 20, 2024 at 3:18 AM Huang Shijie
>>> <shijie@os.amperecomputing.com> wrote:
>>>> The current code passes NUMA_NO_NODE to __alloc_skb(), we found
>>>> it may creates fclone SKB in remote NUMA node.
>>> This is intended (WAI)
>> Okay. thanks a lot.
>>
>> It seems I should fix the issue in other code, not the networking.
>>
>>> What about the NUMA policies of the current thread ?
>> We use "numactl -m 0" for memcached, the NUMA policy should allocate
>> fclone in
>>
>> node 0, but we can see many fclones were allocated in node 1.
>>
>> We have enough memory to allocate these fclones in node 0.
>>
>>> Has NUMA_NO_NODE behavior changed recently?
>> I guess not.
>>> What means : "it may creates" ? Please be more specific.
>> When we use the memcached for testing in NUMA, there are maybe 20% ~ 30%
>> fclones were allocated in
>>
>> remote NUMA node.
> Interesting, how was it measured exactly ?

I created a private patch to record the status for each fclone allocation.

> Are you using SLUB or SLAB ?

I think I use SLUB. (CONFIG_SLUB=y,
CONFIG_SLAB_MERGE_DEFAULT=y,CONFIG_SLUB_CPU_PARTIAL=y)

Thanks

Huang Shijie