Re: [net-next 01/12] i40e: replace switch-statement to speed-up retpoline-enabled builds
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2019-05-02 14:47:52
On 04/29/2019 09:16 PM, Jeff Kirsher wrote:
From: Björn Töpel <redacted> GCC will generate jump tables for switch-statements with more than 5 case statements. An entry into the jump table is an indirect call, which means that for CONFIG_RETPOLINE builds, this is rather expensive. This commit replaces the switch-statement that acts on the XDP program result with an if-clause. The if-clause was also refactored into a common function that can be used by AF_XDP zero-copy and non-zero-copy code.
Isn't it fixed upstream by now already (also in gcc)? https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ce02ef06fcf7a399a6276adb83f37373d10cbbe1 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a9d57ef15cbe327fe54416dd194ee0ea66ae53a4