On 2023-11-21 16:33, Jakub Kicinski wrote:
On Mon, 20 Nov 2023 13:56:09 -0700 Ahmed Zaki wrote:
+ * @data: Extension for the RSS hash function. Valid values are one of the
+ * %RXH_HFUNC_*.
@data is way too generic. Can we call this key_xfrm? key_preproc?
We manipulate the "input data" (protocol fields) not the key. I will
rename to "input_xfrm".
+/* RSS hash function data
+ * XOR the corresponding source and destination fields of each specified
+ * protocol. Both copies of the XOR'ed fields are fed into the RSS and RXHASH
+ * calculation.
+ */
+#define RXH_HFUNC_SYM_XOR (1 << 0)
We need to mention somewhere that sym-xor is unsafe, per Alex's
comments.
I already added the following in Documentation/networking/scaling.rst:
"The Symmetric-XOR" is a type of RSS algorithms that achieves this hash
symmetry by XORing the input source and destination fields of the IP
and/or L4 protocols. This, however, results in reduced input entropy and
could potentially be exploited."
Or do you mean add it also to "uapi/linux/ethtool.h" ?
Will do the rest in the next version.
