netdev - Re: [PATCH net v3 3/3] bnxt_en: handle tpa

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: <a1d5ffda-1e6c-4730-8b36-6ba644bb0118@huawei.com>
Date: Wed, 11 Dec 2024 20:32:42 +0800
From: Yunsheng Lin <linyunsheng@...wei.com>
To: David Wei <dw@...idwei.uk>, <netdev@...r.kernel.org>, Michael Chan
	<michael.chan@...adcom.com>, Andy Gospodarek
	<andrew.gospodarek@...adcom.com>, Somnath Kotur <somnath.kotur@...adcom.com>
CC: Andrew Lunn <andrew+netdev@...n.ch>, "David S. Miller"
	<davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski
	<kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>
Subject: Re: [PATCH net v3 3/3] bnxt_en: handle tpa_info in queue API
 implementation

On 2024/12/11 2:14, David Wei wrote:
> On 2024-12-10 04:25, Yunsheng Lin wrote:
>> On 2024/12/4 12:10, David Wei wrote:
>>
>>>  	bnxt_copy_rx_ring(bp, rxr, clone);
>>> @@ -15563,6 +15580,8 @@ static int bnxt_queue_stop(struct net_device *dev, void *qmem, int idx)
>>>  	bnxt_hwrm_rx_agg_ring_free(bp, rxr, false);
>>>  	rxr->rx_next_cons = 0;
>>>  	page_pool_disable_direct_recycling(rxr->page_pool);
>>> +	if (bnxt_separate_head_pool())
>>> +		page_pool_disable_direct_recycling(rxr->head_pool);
>>
>> Hi, David
>> As mentioned in [1], is the above page_pool_disable_direct_recycling()
>> really needed?
>>
>> Is there any NAPI API called in the implementation of netdev_queue_mgmt_ops?
>> It doesn't seem obvious there is any NAPI API like napi_enable() &
>> ____napi_schedule() that is called in bnxt_queue_start()/bnxt_queue_stop()/
>> bnxt_queue_mem_alloc()/bnxt_queue_mem_free() through code reading.
>>
>> 1. https://lore.kernel.org/all/c2b306af-4817-4169-814b-adbf25803919@huawei.com/
> 
> Hi Yunsheng, there are explicitly no napi_enable/disable() calls in the
> bnxt implementation of netdev_queue_mgmt_ops due to ... let's say HW/FW
> quirks. I looked back at my discussions w/ Broadcom, and IIU/RC
> bnxt_hwrm_vnic_update() will prevent any work from coming into the rxq
> that I'm trying to stop. Calling napi_disable() has unintended side
> effects on the Tx side.

It seems that bnxt_hwrm_vnic_update() sends a VNIC_UPDATE cmd to disable
a VNIC? and a napi_disable() is not needed? Is it possible that there may
be some pending NAPI work is still being processed after bnxt_hwrm_vnic_update()
is called?

> 
> The intent of the call to page_pool_disable_direct_recycling() is to
> prevent pages from the old page pool from being returned into the fast
> cache. These pages must be returned via page_pool_return_page() so that
> the it can eventually be freed in page_pool_release_retry().
> 
> I'm going to take a look at your discussions in [1] and respond there.

Thanks.