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| author | Mina Almasry <almasrymina@google.com> | 2024-11-08 00:03:31 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-11-12 05:11:46 +0300 |
| commit | 102d1404c385611c574498b1e0d1f3762e253359 (patch) | |
| tree | 13bbf79b4c2f2542568787cff06d8f909d3c6346 /Documentation | |
| parent | f2685c00c3222305f5b6740a8b16ea044640283a (diff) | |
| download | linux-102d1404c385611c574498b1e0d1f3762e253359.tar.xz | |
net: clarify SO_DEVMEM_DONTNEED behavior in documentation
Document new behavior when the number of frags passed is too big.
Signed-off-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20241107210331.3044434-2-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/devmem.rst | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/networking/devmem.rst b/Documentation/networking/devmem.rst index a55bf21f671c..d95363645331 100644 --- a/Documentation/networking/devmem.rst +++ b/Documentation/networking/devmem.rst @@ -225,6 +225,15 @@ The user must ensure the tokens are returned to the kernel in a timely manner. Failure to do so will exhaust the limited dmabuf that is bound to the RX queue and will lead to packet drops. +The user must pass no more than 128 tokens, with no more than 1024 total frags +among the token->token_count across all the tokens. If the user provides more +than 1024 frags, the kernel will free up to 1024 frags and return early. + +The kernel returns the number of actual frags freed. The number of frags freed +can be less than the tokens provided by the user in case of: + +(a) an internal kernel leak bug. +(b) the user passed more than 1024 frags. Implementation & Caveats ======================== |