From: Yunsheng Lin <linyunsheng@xxxxxxxxxx> Date: Thu, 29 Jun 2023 20:02:20 +0800 > In [1] & [2] & [3], there are usecases for veth and virtio_net > to use frag support in page pool to reduce memory usage, and it > may request different frag size depending on the head/tail > room space for xdp_frame/shinfo and mtu/packet size. When the > requested frag size is large enough that a single page can not > be split into more than one frag, using frag support only have > performance penalty because of the extra frag count handling > for frag support. > > So this patchset provides a page pool API for the driver to > allocate memory with least memory utilization and performance > penalty when it doesn't know the size of memory it need > beforehand. > > 1. https://patchwork.kernel.org/project/netdevbpf/patch/d3ae6bd3537fbce379382ac6a42f67e22f27ece2.1683896626.git.lorenzo@xxxxxxxxxx/ > 2. https://patchwork.kernel.org/project/netdevbpf/patch/20230526054621.18371-3-liangchen.linux@xxxxxxxxx/ > 3. https://github.com/alobakin/linux/tree/iavf-pp-frag Thanks for sharing the link :D > > v5 RFC: add a new page_pool_cache_alloc() API, and other minor > change as discussed in v4. As there seems to be three > comsumers that might be made use of the new API, so > repost it as RFC and CC the relevant authors to see > if the new API fits their need. Tested v5 against my latest tree, no regressions, perf is even a bit better than it was. That also might've come from that net-next pulled Linus' tree with a good bunch of PRs already merged, or from v4 -> v5 update. Re consumers, I'm planning to send the RFC series with IAVF as a consumer on Monday (and a couple generic Page Pool improvements today, will see). > > V4. Fix a typo and add a patch to update document about frag > API, PAGE_POOL_DMA_USE_PP_FRAG_COUNT is not renamed yet > as we may need a different thread to discuss that. > > V3: Incorporate changes from the disscusion with Alexander, > mostly the inline wraper, PAGE_POOL_DMA_USE_PP_FRAG_COUNT > change split to separate patch and comment change. > V2: Add patch to remove PP_FLAG_PAGE_FRAG flags and mention > virtio_net usecase in the cover letter. > V1: Drop RFC tag and page_pool_frag patch. Thanks, Olek
