Convert the ice driver to Page Pool [POC] #8
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The commit 5384467 ("iavf: kill "legacy-rx" for good") removes the legacy Rx in iavf driver. Now it is time for ice. Converting the page management to page_pool is a good opportunity to remove an obsolete code per the arguments listed in the original iavf commit. Co-developed-by: Alexander Lobakin <[email protected]> Signed-off-by: Michal Kubiak <[email protected]>
As in case of iavf driver, the commit 920d86f ("iavf: drop page splitting and recycling") introduces an intermediate step in page_pool conversion, perform the same step for ice. Remove all page splitting/recycling code. Just always allocate a new page and don't touch its refcount, so that it gets freed by the core stack later. Co-developed-by: Alexander Lobakin <[email protected]> Signed-off-by: Michal Kubiak <[email protected]>
The patch is the ice version of the IAVF commit 5fa4caf ("iavf: switch to Page Pool"), enhanced with XDP stuff conversion. Generic Rx path changes can be described in exactly the same way as the original IAVF commit. Now that the ice driver simply uses dev_alloc_page() + free_page() with no custom recycling logics, it can easily be switched to using Page Pool / libeth API instead. This allows to removing the whole dancing around headroom, HW buffer size, and page order. All DMA-for-device is now done in the PP core, for-CPU -- in the libeth helper. Use skb_mark_for_recycle() to bring back the recycling and restore the performance. In terms of XDP, use basic XDP helpers provided by the libeth_xdp module. For XDP_TX skip DMA mapping for each xmitted frame. Instead, map all buffers as bi-directional and rely on the page_pool page management mechanism. Thanks to this, performance of XDP_TX can be improved, especially in scenarios when IOMMU is enabled. Suggested-by: Maciej Fijalkowski <[email protected]> Suggested-by: Alexander Lobakin <[email protected]> Signed-off-by: Michal Kubiak <[email protected]>
Since the ice driver uses the same Rx path for handling regular NAPI Rx queues as well as control VSI flow director queues, the page_pool could not be applied in a generic way. Skip that design issue temporarily, just to avoid the POC crashes, by disabling the flow director completely. The issue has to be addressed after we decide to upstream that page_pool solution. Signed-off-by: Michal Kubiak <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
No description provided.