8fb472c09b
Recently we started using ipmr with thousands of entries and easily hit soft lockups on smaller devices. The reason is that the hash function uses the high order bits from the src and dst, but those don't change in many common cases, also the hash table is only 64 elements so with thousands it doesn't scale at all. This patch migrates the hash table to rhashtable, and in particular the rhl interface which allows for duplicate elements to be chained because of the MFC_PROXY support (*,G; *,*,oif cases) which allows for multiple duplicate entries to be added with different interfaces (IMO wrong, but it's been in for a long time). And here are some results from tests I've run in a VM: mr_table size (default, allocated for all namespaces): Before After 49304 bytes 2400 bytes Add 65000 routes (the diff is much larger on smaller devices): Before After 1m42s 58s Forwarding 256 byte packets with 65000 routes (test done in a VM): Before After 3 Mbps / ~1465 pps 122 Mbps / ~59000 pps As a bonus we no longer see the soft lockups on smaller devices which showed up even with 2000 entries before. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> 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.