netdev - Re: [PATCH v6 net-next 1/5] net: add generic per-cpu page

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7343292d-3273-a10a-9167-420f3232dbdd@huawei.com>
Date: Tue, 30 Jan 2024 19:02:22 +0800
From: Yunsheng Lin <linyunsheng@...wei.com>
To: Lorenzo Bianconi <lorenzo.bianconi@...hat.com>
CC: Lorenzo Bianconi <lorenzo@...nel.org>, <netdev@...r.kernel.org>,
	<davem@...emloft.net>, <kuba@...nel.org>, <edumazet@...gle.com>,
	<pabeni@...hat.com>, <bpf@...r.kernel.org>, <toke@...hat.com>,
	<willemdebruijn.kernel@...il.com>, <jasowang@...hat.com>, <sdf@...gle.com>,
	<hawk@...nel.org>, <ilias.apalodimas@...aro.org>
Subject: Re: [PATCH v6 net-next 1/5] net: add generic per-cpu page_pool
 allocator

On 2024/1/29 21:04, Lorenzo Bianconi wrote:
>> On 2024/1/28 22:20, Lorenzo Bianconi wrote:
>>
>>>  #ifdef CONFIG_LOCKDEP
>>>  /*
>>>   * register_netdevice() inits txq->_xmit_lock and sets lockdep class
>>> @@ -11686,6 +11690,27 @@ static void __init net_dev_struct_check(void)
>>>   *
>>>   */
>>>  
>>> +#define SD_PAGE_POOL_RING_SIZE	256
>>
>> I might missed that if there is a reason we choose 256 here, do we
>> need to use different value for differe page size, for 64K page size,
>> it means we might need to reserve 16MB memory for each CPU.
> 
> honestly I have not spent time on it, most of the current page_pool users set
> pool_size to 256. Anyway, do you mean something like:
> 
> diff --git a/net/core/dev.c b/net/core/dev.c
> index f70fb6cad2b2..3934a3fc5c45 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -11806,12 +11806,11 @@ static void __init net_dev_struct_check(void)
>   *
>   */
>  
> -#define SD_PAGE_POOL_RING_SIZE	256
>  static int net_page_pool_alloc(int cpuid)
>  {
>  #if IS_ENABLED(CONFIG_PAGE_POOL)

Isn't better to have a config like CONFIG_PER_CPU_PAGE_POOL to enable
this feature? and this config can be selected by whoever needs this
feature?

>  	struct page_pool_params page_pool_params = {
> -		.pool_size = SD_PAGE_POOL_RING_SIZE,
> +		.pool_size = PAGE_SIZE < SZ_64K ? 256 : 16,

What about other page size? like 16KB?
How about something like below:
PAGE_SIZE << get_order(PER_CPU_PAGE_POOL_MAX_SIZE)

>  		.nid = NUMA_NO_NODE,
>  	};
>  	struct page_pool *pp_ptr;