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Jesper Dangaard Brouer says: ==================== net: optimize ICMP-reply code path This patchset is optimizing the ICMP-reply code path, for ICMP packets that gets rate limited. A remote party can easily trigger this code path by sending packets to port number with no listening service. Generally the patchset moves the sysctl_icmp_msgs_per_sec ratelimit checking to earlier in the code path and removes an allocation. Use-case: The specific case I experienced this being a bottleneck is, sending UDP packets to a port with no listener, which obviously result in kernel replying with ICMP Destination Unreachable (type:3), Port Unreachable (code:3), which cause the bottleneck. After Eric and Paolo optimized the UDP socket code, the kernels PPS processing capabilities is lower for no-listen ports, than normal UDP sockets. This is bad for capacity planning when restarting a service. UDP no-listen benchmark 8xCPUs using pktgen_sample04_many_flows.sh: Baseline: 6.6 Mpps Patch: 14.7 Mpps Driver mlx5 at 50Gbit/s. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.