Re: [Intel-wired-lan] [PATCH net-next v5 03/14] page_pool: avoid calling no-op externals when possible

From: Alexander Lobakin <aleksander.lobakin@intel.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>,
	Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
	Jesper Dangaard Brouer <hawk@kernel.org>,
	Eric Dumazet <edumazet@google.com>,
	Larysa Zaremba <larysa.zaremba@intel.com>,
	netdev@vger.kernel.org, Alexander Duyck <alexanderduyck@fb.com>,
	Ilias Apalodimas <ilias.apalodimas@linaro.org>,
	linux-kernel@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Yunsheng Lin <linyunsheng@huawei.com>,
	Michal Kubiak <michal.kubiak@intel.com>,
	intel-wired-lan@lists.osuosl.org,
	David Christensen <drc@linux.vnet.ibm.com>,
	Paolo Abeni <pabeni@redhat.com>, Christoph Hellwig <hch@lst.de>
Subject: Re: [Intel-wired-lan] [PATCH net-next v5 03/14] page_pool: avoid calling no-op externals when possible
Date: Tue, 28 Nov 2023 17:50:57 +0100	[thread overview]
Message-ID: <9a65e703-3476-4584-bec0-8f41198d840f@intel.com> (raw)
In-Reply-To: <20231127101720.282862f6@kernel.org>

From: Jakub Kicinski <kuba@kernel.org>
Date: Mon, 27 Nov 2023 10:17:20 -0800

> On Mon, 27 Nov 2023 15:32:19 +0100 Alexander Lobakin wrote:
>>> Sorry for not remembering the suggestion:(  
>>
>> In the previous versions of this change I used a global flag per whole
>> page_pool, just like XSk does for the whole XSk buff pool, then you
>> proposed to use the lowest bit of ::dma_addr and store it per page, so
>> that it would be more granular/precise. I tested it and it doesn't
>> perform worse than global, but in some cases may be beneficial.
> 
> FWIW I'd vote to stick to per-page pool. You seem to handle the
> sizeof(dma_addr_t) > sizeof(long) case correctly but the code is
> growing in complexity, providing no known/measurable benefit.
> We can always do this later but for now it seems like a premature
> optimization to me.

Yeah, this also seems more logical and optimal to me. Will wait a bit
for a possible reply from Chris and then send the next rev.

Thanks,
Olek
_______________________________________________
Intel-wired-lan mailing list
Intel-wired-lan@osuosl.org
https://lists.osuosl.org/mailman/listinfo/intel-wired-lan