Messages in this thread | | | Date | Fri, 4 Aug 2023 12:49:37 +0200 | Subject | Re: [PATCH V5,net-next] net: mana: Add page pool for RX buffers | From | Jesper Dangaard Brouer <> |
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On 03/08/2023 03.44, Jesse Brandeburg wrote: > On 8/2/2023 11:07 AM, Haiyang Zhang wrote: >> Add page pool for RX buffers for faster buffer cycle and reduce CPU >> usage. >>
Can you add some info on the performance improvement this patch gives?
Your previous post mentioned: > With iperf and 128 threads test, this patch improved the throughput by 12-15%, and decreased the IRQ associated CPU's usage from 99-100% to 10-50%.
>> The standard page pool API is used. >> >> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> >> --- >> V5: >> In err path, set page_pool_put_full_page(..., false) as suggested by >> Jakub Kicinski >> V4: >> Add nid setting, remove page_pool_nid_changed(), as suggested by >> Jesper Dangaard Brouer >> V3: >> Update xdp mem model, pool param, alloc as suggested by Jakub Kicinski >> V2: >> Use the standard page pool API as suggested by Jesper Dangaard Brouer >> --- > >> diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h >> index 024ad8ddb27e..b12859511839 100644 >> --- a/include/net/mana/mana.h >> +++ b/include/net/mana/mana.h >> @@ -280,6 +280,7 @@ struct mana_recv_buf_oob { >> struct gdma_wqe_request wqe_req; >> >> void *buf_va; >> + bool from_pool; /* allocated from a page pool */ > > suggest you use flags and not bools, as bools waste 7 bits each, plus > your packing of this struct will be full of holes, made worse by this > patch. (see pahole tool) >
Agreed.
> >> >> /* SGL of the buffer going to be sent has part of the work request. */ >> u32 num_sge; >> @@ -330,6 +331,8 @@ struct mana_rxq { >> bool xdp_flush; >> int xdp_rc; /* XDP redirect return code */ >> >> + struct page_pool *page_pool; >> + >> /* MUST BE THE LAST MEMBER: >> * Each receive buffer has an associated mana_recv_buf_oob. >> */ > > > The rest of the patch looks ok and is remarkably compact for a > conversion to page pool. I'd prefer someone with more page pool exposure > review this for correctness, but FWIW >
Both Jakub and I have reviewed the page_pool parts, and I think we are in a good place.
Looking at the driver, I wonder why you are keeping the driver local memory cache (when PP is also contains a memory cache) ? (I assume there is a good reason, so this is not blocking patch)
> > Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Thanks for taking your time to review.
I'm ready to ACK once the description is improved a bit :-)
--Jesper pw-bot: cr
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