Messages in this thread | | | Date | Tue, 30 May 2023 18:22:07 +0200 | Subject | Re: [PATCH net-next v2 02/12] iavf: kill "legacy-rx" for good | From | Alexander Lobakin <> |
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From: Alexander H Duyck <alexander.duyck@gmail.com> Date: Tue, 30 May 2023 08:29:10 -0700
> On Thu, 2023-05-25 at 14:57 +0200, Alexander Lobakin wrote: >> Ever since build_skb() became stable, the old way with allocating an skb >> for storing the headers separately, which will be then copied manually, >> was slower, less flexible and thus obsolete.
[...]
> The "legacy-rx" was never about performance. It was mostly about > providing a fall back in the event of an unexpected behavior. Keep in > mind that in order to enable this we are leaving the page mapped and > syncing it multiple times. In order to enable support for this we had > to add several new items that I had deemed to be a bit risky such as > support for DMA pages that were synced by the driver instead of on > map/unmap and the use of the build_skb logic.
And now pretty much every driver doesn't do map/unmap each time and keeps its mapping for a very long time. And now Chris noticed that and says it's not supposed to be used like that :D
> > My main concern was that if we ever ran into header corruption we > could switch this on and then the pages would only be writable by the > device.
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> Since it has been about 6 years without any issues I would say we are > safe to remove it. > > Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Thanks! Olek
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